Provided by: libguestfs-perl_1.32.2-4ubuntu2.2_amd64 
NAME
Sys::Guestfs - Perl bindings for libguestfs
SYNOPSIS
use Sys::Guestfs;
my $g = Sys::Guestfs->new ();
$g->add_drive_opts ('guest.img', format => 'raw');
$g->launch ();
$g->mount ('/dev/sda1', '/');
$g->touch ('/hello');
$g->shutdown ();
$g->close ();
DESCRIPTION
The "Sys::Guestfs" module provides a Perl XS binding to the libguestfs API for examining
and modifying virtual machine disk images.
Amongst the things this is good for: making batch configuration changes to guests, getting
disk used/free statistics (see also: virt-df), migrating between virtualization systems
(see also: virt-p2v), performing partial backups, performing partial guest clones, cloning
guests and changing registry/UUID/hostname info, and much else besides.
Libguestfs uses Linux kernel and qemu code, and can access any type of guest filesystem
that Linux and qemu can, including but not limited to: ext2/3/4, btrfs, FAT and NTFS, LVM,
many different disk partition schemes, qcow, qcow2, vmdk.
Libguestfs provides ways to enumerate guest storage (eg. partitions, LVs, what filesystem
is in each LV, etc.). It can also run commands in the context of the guest. Also you can
access filesystems over FUSE.
ERRORS
All errors turn into calls to "croak" (see Carp(3)).
The error string from libguestfs is directly available from $@. Use the "last_errno"
method if you want to get the errno.
METHODS
$g = Sys::Guestfs->new ([environment => 0,] [close_on_exit => 0]);
Create a new guestfs handle.
If the optional argument "environment" is false, then the
"GUESTFS_CREATE_NO_ENVIRONMENT" flag is set.
If the optional argument "close_on_exit" is false, then the
"GUESTFS_CREATE_NO_CLOSE_ON_EXIT" flag is set.
$g->close ();
Explicitly close the guestfs handle.
Note: You should not usually call this function. The handle will be closed implicitly
when its reference count goes to zero (eg. when it goes out of scope or the program
ends). This call is only required in some exceptional cases, such as where the
program may contain cached references to the handle 'somewhere' and you really have to
have the close happen right away. After calling "close" the program must not call any
method (including "close") on the handle (but the implicit call to "DESTROY" that
happens when the final reference is cleaned up is OK).
$Sys::Guestfs::EVENT_CLOSE
See "GUESTFS_EVENT_CLOSE" in guestfs(3).
$Sys::Guestfs::EVENT_SUBPROCESS_QUIT
See "GUESTFS_EVENT_SUBPROCESS_QUIT" in guestfs(3).
$Sys::Guestfs::EVENT_LAUNCH_DONE
See "GUESTFS_EVENT_LAUNCH_DONE" in guestfs(3).
$Sys::Guestfs::EVENT_PROGRESS
See "GUESTFS_EVENT_PROGRESS" in guestfs(3).
$Sys::Guestfs::EVENT_APPLIANCE
See "GUESTFS_EVENT_APPLIANCE" in guestfs(3).
$Sys::Guestfs::EVENT_LIBRARY
See "GUESTFS_EVENT_LIBRARY" in guestfs(3).
$Sys::Guestfs::EVENT_TRACE
See "GUESTFS_EVENT_TRACE" in guestfs(3).
$Sys::Guestfs::EVENT_ENTER
See "GUESTFS_EVENT_ENTER" in guestfs(3).
$Sys::Guestfs::EVENT_LIBVIRT_AUTH
See "GUESTFS_EVENT_LIBVIRT_AUTH" in guestfs(3).
$Sys::Guestfs::EVENT_WARNING
See "GUESTFS_EVENT_WARNING" in guestfs(3).
$Sys::Guestfs::EVENT_ALL
See "GUESTFS_EVENT_ALL" in guestfs(3).
$event_handle = $g->set_event_callback (\&cb, $event_bitmask);
Register "cb" as a callback function for all of the events in $event_bitmask (one or
more "$Sys::Guestfs::EVENT_*" flags logically or'd together).
This function returns an event handle which can be used to delete the callback using
"delete_event_callback".
The callback function receives 4 parameters:
&cb ($event, $event_handle, $buf, $array)
$event
The event which happened (equal to one of "$Sys::Guestfs::EVENT_*").
$event_handle
The event handle.
$buf
For some event types, this is a message buffer (ie. a string).
$array
For some event types (notably progress events), this is an array of integers.
You should carefully read the documentation for "guestfs_set_event_callback" in
guestfs(3) before using this function.
$g->delete_event_callback ($event_handle);
This removes the callback which was previously registered using "set_event_callback".
$str = Sys::Guestfs::event_to_string ($events);
$events is either a single event or a bitmask of events. This returns a printable
string, useful for debugging.
Note that this is a class function, not a method.
$errnum = $g->last_errno ();
This returns the last error number (errno) that happened on the handle $g.
If successful, an errno integer not equal to zero is returned.
If no error number is available, this returns 0. See "guestfs_last_errno" in
guestfs(3) for more details of why this can happen.
You can use the standard Perl module Errno(3) to compare the numeric error returned
from this call with symbolic errnos:
$g->mkdir ("/foo");
if ($g->last_errno() == Errno::EEXIST()) {
# mkdir failed because the directory exists already.
}
$g->acl_delete_def_file ($dir);
This function deletes the default POSIX Access Control List (ACL) attached to
directory "dir".
$acl = $g->acl_get_file ($path, $acltype);
This function returns the POSIX Access Control List (ACL) attached to "path". The ACL
is returned in "long text form" (see acl(5)).
The "acltype" parameter may be:
"access"
Return the ordinary (access) ACL for any file, directory or other filesystem
object.
"default"
Return the default ACL. Normally this only makes sense if "path" is a directory.
$g->acl_set_file ($path, $acltype, $acl);
This function sets the POSIX Access Control List (ACL) attached to "path".
The "acltype" parameter may be:
"access"
Set the ordinary (access) ACL for any file, directory or other filesystem object.
"default"
Set the default ACL. Normally this only makes sense if "path" is a directory.
The "acl" parameter is the new ACL in either "long text form" or "short text form"
(see acl(5)). The new ACL completely replaces any previous ACL on the file. The ACL
must contain the full Unix permissions (eg. "u::rwx,g::rx,o::rx").
If you are specifying individual users or groups, then the mask field is also required
(eg. "m::rwx"), followed by the "u:ID:..." and/or "g:ID:..." field(s). A full ACL
string might therefore look like this:
u::rwx,g::rwx,o::rwx,m::rwx,u:500:rwx,g:500:rwx
\ Unix permissions / \mask/ \ ACL /
You should use numeric UIDs and GIDs. To map usernames and groupnames to the correct
numeric ID in the context of the guest, use the Augeas functions (see "$g->aug_init").
$g->add_cdrom ($filename);
This function adds a virtual CD-ROM disk image to the guest.
The image is added as read-only drive, so this function is equivalent of
"$g->add_drive_ro".
This function is deprecated. In new code, use the "add_drive_ro" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$nrdisks = $g->add_domain ($dom [, libvirturi => $libvirturi] [, readonly => $readonly] [,
iface => $iface] [, live => $live] [, allowuuid => $allowuuid] [, readonlydisk =>
$readonlydisk] [, cachemode => $cachemode] [, discard => $discard] [, copyonread =>
$copyonread]);
This function adds the disk(s) attached to the named libvirt domain "dom". It works
by connecting to libvirt, requesting the domain and domain XML from libvirt, parsing
it for disks, and calling "$g->add_drive_opts" on each one.
The number of disks added is returned. This operation is atomic: if an error is
returned, then no disks are added.
This function does some minimal checks to make sure the libvirt domain is not running
(unless "readonly" is true). In a future version we will try to acquire the libvirt
lock on each disk.
Disks must be accessible locally. This often means that adding disks from a remote
libvirt connection (see <http://libvirt.org/remote.html>) will fail unless those disks
are accessible via the same device path locally too.
The optional "libvirturi" parameter sets the libvirt URI (see
<http://libvirt.org/uri.html>). If this is not set then we connect to the default
libvirt URI (or one set through an environment variable, see the libvirt documentation
for full details).
The optional "live" flag controls whether this call will try to connect to a running
virtual machine "guestfsd" process if it sees a suitable <channel> element in the
libvirt XML definition. The default (if the flag is omitted) is never to try. See
"ATTACHING TO RUNNING DAEMONS" in guestfs(3) for more information.
If the "allowuuid" flag is true (default is false) then a UUID may be passed instead
of the domain name. The "dom" string is treated as a UUID first and looked up, and if
that lookup fails then we treat "dom" as a name as usual.
The optional "readonlydisk" parameter controls what we do for disks which are marked
<readonly/> in the libvirt XML. Possible values are:
readonlydisk = "error"
If "readonly" is false:
The whole call is aborted with an error if any disk with the <readonly/> flag is
found.
If "readonly" is true:
Disks with the <readonly/> flag are added read-only.
readonlydisk = "read"
If "readonly" is false:
Disks with the <readonly/> flag are added read-only. Other disks are added
read/write.
If "readonly" is true:
Disks with the <readonly/> flag are added read-only.
readonlydisk = "write" (default)
If "readonly" is false:
Disks with the <readonly/> flag are added read/write.
If "readonly" is true:
Disks with the <readonly/> flag are added read-only.
readonlydisk = "ignore"
If "readonly" is true or false:
Disks with the <readonly/> flag are skipped.
The other optional parameters are passed directly through to "$g->add_drive_opts".
$g->add_drive ($filename [, readonly => $readonly] [, format => $format] [, iface =>
$iface] [, name => $name] [, label => $label] [, protocol => $protocol] [, server =>
$server] [, username => $username] [, secret => $secret] [, cachemode => $cachemode] [,
discard => $discard] [, copyonread => $copyonread]);
This function adds a disk image called filename to the handle. filename may be a
regular host file or a host device.
When this function is called before "$g->launch" (the usual case) then the first time
you call this function, the disk appears in the API as /dev/sda, the second time as
/dev/sdb, and so on.
In libguestfs X 1.20 you can also call this function after launch (with some
restrictions). This is called "hotplugging". When hotplugging, you must specify a
"label" so that the new disk gets a predictable name. For more information see
"HOTPLUGGING" in guestfs(3).
You don't necessarily need to be root when using libguestfs. However you obviously do
need sufficient permissions to access the filename for whatever operations you want to
perform (ie. read access if you just want to read the image or write access if you
want to modify the image).
This call checks that filename exists.
filename may be the special string "/dev/null". See "NULL DISKS" in guestfs(3).
The optional arguments are:
"readonly"
If true then the image is treated as read-only. Writes are still allowed, but
they are stored in a temporary snapshot overlay which is discarded at the end.
The disk that you add is not modified.
"format"
This forces the image format. If you omit this (or use "$g->add_drive" or
"$g->add_drive_ro") then the format is automatically detected. Possible formats
include "raw" and "qcow2".
Automatic detection of the format opens you up to a potential security hole when
dealing with untrusted raw-format images. See CVE-2010-3851 and RHBZ#642934.
Specifying the format closes this security hole.
"iface"
This rarely-used option lets you emulate the behaviour of the deprecated
"$g->add_drive_with_if" call (q.v.)
"name"
The name the drive had in the original guest, e.g. /dev/sdb. This is used as a
hint to the guest inspection process if it is available.
"label"
Give the disk a label. The label should be a unique, short string using only
ASCII characters "[a-zA-Z]". As well as its usual name in the API (such as
/dev/sda), the drive will also be named /dev/disk/guestfs/label.
See "DISK LABELS" in guestfs(3).
"protocol"
The optional protocol argument can be used to select an alternate source protocol.
See also: "REMOTE STORAGE" in guestfs(3).
"protocol = "file""
filename is interpreted as a local file or device. This is the default if the
optional protocol parameter is omitted.
"protocol = "ftp"|"ftps"|"http"|"https"|"tftp""
Connect to a remote FTP, HTTP or TFTP server. The "server" parameter must
also be supplied - see below.
See also: "FTP, HTTP AND TFTP" in guestfs(3)
"protocol = "gluster""
Connect to the GlusterFS server. The "server" parameter must also be supplied
- see below.
See also: "GLUSTER" in guestfs(3)
"protocol = "iscsi""
Connect to the iSCSI server. The "server" parameter must also be supplied -
see below. The "username" parameter may be supplied. See below. The
"secret" parameter may be supplied. See below.
See also: "ISCSI" in guestfs(3).
"protocol = "nbd""
Connect to the Network Block Device server. The "server" parameter must also
be supplied - see below.
See also: "NETWORK BLOCK DEVICE" in guestfs(3).
"protocol = "rbd""
Connect to the Ceph (librbd/RBD) server. The "server" parameter must also be
supplied - see below. The "username" parameter may be supplied. See below.
The "secret" parameter may be supplied. See below.
See also: "CEPH" in guestfs(3).
"protocol = "sheepdog""
Connect to the Sheepdog server. The "server" parameter may also be supplied -
see below.
See also: "SHEEPDOG" in guestfs(3).
"protocol = "ssh""
Connect to the Secure Shell (ssh) server.
The "server" parameter must be supplied. The "username" parameter may be
supplied. See below.
See also: "SSH" in guestfs(3).
"server"
For protocols which require access to a remote server, this is a list of
server(s).
Protocol Number of servers required
-------- --------------------------
file List must be empty or param not used at all
ftp|ftps|http|https|tftp Exactly one
gluster Exactly one
iscsi Exactly one
nbd Exactly one
rbd Zero or more
sheepdog Zero or more
ssh Exactly one
Each list element is a string specifying a server. The string must be in one of
the following formats:
hostname
hostname:port
tcp:hostname
tcp:hostname:port
unix:/path/to/socket
If the port number is omitted, then the standard port number for the protocol is
used (see /etc/services).
"username"
For the "ftp", "ftps", "http", "https", "iscsi", "rbd", "ssh" and "tftp"
protocols, this specifies the remote username.
If not given, then the local username is used for "ssh", and no authentication is
attempted for ceph. But note this sometimes may give unexpected results, for
example if using the libvirt backend and if the libvirt backend is configured to
start the qemu appliance as a special user such as "qemu.qemu". If in doubt,
specify the remote username you want.
"secret"
For the "rbd" protocol only, this specifies the 'secret' to use when connecting to
the remote device. It must be base64 encoded.
If not given, then a secret matching the given username will be looked up in the
default keychain locations, or if no username is given, then no authentication
will be used.
"cachemode"
Choose whether or not libguestfs will obey sync operations (safe but slow) or not
(unsafe but fast). The possible values for this string are:
"cachemode = "writeback""
This is the default.
Write operations in the API do not return until a write(2) call has completed
in the host [but note this does not imply that anything gets written to disk].
Sync operations in the API, including implicit syncs caused by filesystem
journalling, will not return until an fdatasync(2) call has completed in the
host, indicating that data has been committed to disk.
"cachemode = "unsafe""
In this mode, there are no guarantees. Libguestfs may cache anything and
ignore sync requests. This is suitable only for scratch or temporary disks.
"discard"
Enable or disable discard (a.k.a. trim or unmap) support on this drive. If
enabled, operations such as "$g->fstrim" will be able to discard / make thin /
punch holes in the underlying host file or device.
Possible discard settings are:
"discard = "disable""
Disable discard support. This is the default.
"discard = "enable""
Enable discard support. Fail if discard is not possible.
"discard = "besteffort""
Enable discard support if possible, but don't fail if it is not supported.
Since not all backends and not all underlying systems support discard, this is
a good choice if you want to use discard if possible, but don't mind if it
doesn't work.
"copyonread"
The boolean parameter "copyonread" enables copy-on-read support. This only
affects disk formats which have backing files, and causes reads to be stored in
the overlay layer, speeding up multiple reads of the same area of disk.
The default is false.
$g->add_drive_opts ($filename [, readonly => $readonly] [, format => $format] [, iface =>
$iface] [, name => $name] [, label => $label] [, protocol => $protocol] [, server =>
$server] [, username => $username] [, secret => $secret] [, cachemode => $cachemode] [,
discard => $discard] [, copyonread => $copyonread]);
This is an alias of "add_drive".
$g->add_drive_ro ($filename);
This function is the equivalent of calling "$g->add_drive_opts" with the optional
parameter "GUESTFS_ADD_DRIVE_OPTS_READONLY" set to 1, so the disk is added read-only,
with the format being detected automatically.
$g->add_drive_ro_with_if ($filename, $iface);
This is the same as "$g->add_drive_ro" but it allows you to specify the QEMU interface
emulation to use at run time.
This function is deprecated. In new code, use the "add_drive" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->add_drive_scratch ($size [, name => $name] [, label => $label]);
This command adds a temporary scratch drive to the handle. The "size" parameter is
the virtual size (in bytes). The scratch drive is blank initially (all reads return
zeroes until you start writing to it). The drive is deleted when the handle is
closed.
The optional arguments "name" and "label" are passed through to "$g->add_drive".
$g->add_drive_with_if ($filename, $iface);
This is the same as "$g->add_drive" but it allows you to specify the QEMU interface
emulation to use at run time.
This function is deprecated. In new code, use the "add_drive" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$nrdisks = $g->add_libvirt_dom ($dom [, readonly => $readonly] [, iface => $iface] [, live
=> $live] [, readonlydisk => $readonlydisk] [, cachemode => $cachemode] [, discard =>
$discard] [, copyonread => $copyonread]);
This function adds the disk(s) attached to the libvirt domain "dom". It works by
requesting the domain XML from libvirt, parsing it for disks, and calling
"$g->add_drive_opts" on each one.
In the C API we declare "void *dom", but really it has type "virDomainPtr dom". This
is so we don't need <libvirt.h>.
The number of disks added is returned. This operation is atomic: if an error is
returned, then no disks are added.
This function does some minimal checks to make sure the libvirt domain is not running
(unless "readonly" is true). In a future version we will try to acquire the libvirt
lock on each disk.
Disks must be accessible locally. This often means that adding disks from a remote
libvirt connection (see <http://libvirt.org/remote.html>) will fail unless those disks
are accessible via the same device path locally too.
The optional "live" flag controls whether this call will try to connect to a running
virtual machine "guestfsd" process if it sees a suitable <channel> element in the
libvirt XML definition. The default (if the flag is omitted) is never to try. See
"ATTACHING TO RUNNING DAEMONS" in guestfs(3) for more information.
The optional "readonlydisk" parameter controls what we do for disks which are marked
<readonly/> in the libvirt XML. See "$g->add_domain" for possible values.
The other optional parameters are passed directly through to "$g->add_drive_opts".
$g->aug_clear ($augpath);
Set the value associated with "path" to "NULL". This is the same as the augtool(1)
"clear" command.
$g->aug_close ();
Close the current Augeas handle and free up any resources used by it. After calling
this, you have to call "$g->aug_init" again before you can use any other Augeas
functions.
%nrnodescreated = $g->aug_defnode ($name, $expr, $val);
Defines a variable "name" whose value is the result of evaluating "expr".
If "expr" evaluates to an empty nodeset, a node is created, equivalent to calling
"$g->aug_set" "expr", "value". "name" will be the nodeset containing that single
node.
On success this returns a pair containing the number of nodes in the nodeset, and a
boolean flag if a node was created.
$nrnodes = $g->aug_defvar ($name, $expr);
Defines an Augeas variable "name" whose value is the result of evaluating "expr". If
"expr" is NULL, then "name" is undefined.
On success this returns the number of nodes in "expr", or 0 if "expr" evaluates to
something which is not a nodeset.
$val = $g->aug_get ($augpath);
Look up the value associated with "path". If "path" matches exactly one node, the
"value" is returned.
$g->aug_init ($root, $flags);
Create a new Augeas handle for editing configuration files. If there was any previous
Augeas handle associated with this guestfs session, then it is closed.
You must call this before using any other "$g->aug_*" commands.
"root" is the filesystem root. "root" must not be NULL, use / instead.
The flags are the same as the flags defined in <augeas.h>, the logical or of the
following integers:
"AUG_SAVE_BACKUP" = 1
Keep the original file with a ".augsave" extension.
"AUG_SAVE_NEWFILE" = 2
Save changes into a file with extension ".augnew", and do not overwrite original.
Overrides "AUG_SAVE_BACKUP".
"AUG_TYPE_CHECK" = 4
Typecheck lenses.
This option is only useful when debugging Augeas lenses. Use of this option may
require additional memory for the libguestfs appliance. You may need to set the
"LIBGUESTFS_MEMSIZE" environment variable or call "$g->set_memsize".
"AUG_NO_STDINC" = 8
Do not use standard load path for modules.
"AUG_SAVE_NOOP" = 16
Make save a no-op, just record what would have been changed.
"AUG_NO_LOAD" = 32
Do not load the tree in "$g->aug_init".
To close the handle, you can call "$g->aug_close".
To find out more about Augeas, see <http://augeas.net/>.
$g->aug_insert ($augpath, $label, $before);
Create a new sibling "label" for "path", inserting it into the tree before or after
"path" (depending on the boolean flag "before").
"path" must match exactly one existing node in the tree, and "label" must be a label,
ie. not contain /, "*" or end with a bracketed index "[N]".
$label = $g->aug_label ($augpath);
The label (name of the last element) of the Augeas path expression "augpath" is
returned. "augpath" must match exactly one node, else this function returns an error.
$g->aug_load ();
Load files into the tree.
See "aug_load" in the Augeas documentation for the full gory details.
@matches = $g->aug_ls ($augpath);
This is just a shortcut for listing "$g->aug_match" "path/*" and sorting the resulting
nodes into alphabetical order.
@matches = $g->aug_match ($augpath);
Returns a list of paths which match the path expression "path". The returned paths
are sufficiently qualified so that they match exactly one node in the current tree.
$g->aug_mv ($src, $dest);
Move the node "src" to "dest". "src" must match exactly one node. "dest" is
overwritten if it exists.
$nrnodes = $g->aug_rm ($augpath);
Remove "path" and all of its children.
On success this returns the number of entries which were removed.
$g->aug_save ();
This writes all pending changes to disk.
The flags which were passed to "$g->aug_init" affect exactly how files are saved.
$g->aug_set ($augpath, $val);
Set the value associated with "path" to "val".
In the Augeas API, it is possible to clear a node by setting the value to NULL. Due
to an oversight in the libguestfs API you cannot do that with this call. Instead you
must use the "$g->aug_clear" call.
$nodes = $g->aug_setm ($base, $sub, $val);
Change multiple Augeas nodes in a single operation. "base" is an expression matching
multiple nodes. "sub" is a path expression relative to "base". All nodes matching
"base" are found, and then for each node, "sub" is changed to "val". "sub" may also
be "NULL" in which case the "base" nodes are modified.
This returns the number of nodes modified.
$g->available (\@groups);
This command is used to check the availability of some groups of functionality in the
appliance, which not all builds of the libguestfs appliance will be able to provide.
The libguestfs groups, and the functions that those groups correspond to, are listed
in "AVAILABILITY" in guestfs(3). You can also fetch this list at runtime by calling
"$g->available_all_groups".
The argument "groups" is a list of group names, eg: "["inotify", "augeas"]" would
check for the availability of the Linux inotify functions and Augeas (configuration
file editing) functions.
The command returns no error if all requested groups are available.
It fails with an error if one or more of the requested groups is unavailable in the
appliance.
If an unknown group name is included in the list of groups then an error is always
returned.
Notes:
• "$g->feature_available" is the same as this call, but with a slightly simpler to
use API: that call returns a boolean true/false instead of throwing an error.
• You must call "$g->launch" before calling this function.
The reason is because we don't know what groups are supported by the
appliance/daemon until it is running and can be queried.
• If a group of functions is available, this does not necessarily mean that they
will work. You still have to check for errors when calling individual API
functions even if they are available.
• It is usually the job of distro packagers to build complete functionality into the
libguestfs appliance. Upstream libguestfs, if built from source with all
requirements satisfied, will support everything.
• This call was added in version 1.0.80. In previous versions of libguestfs all you
could do would be to speculatively execute a command to find out if the daemon
implemented it. See also "$g->version".
See also "$g->filesystem_available".
@groups = $g->available_all_groups ();
This command returns a list of all optional groups that this daemon knows about. Note
this returns both supported and unsupported groups. To find out which ones the daemon
can actually support you have to call "$g->available" / "$g->feature_available" on
each member of the returned list.
See also "$g->available", "$g->feature_available" and "AVAILABILITY" in guestfs(3).
$g->base64_in ($base64file, $filename);
This command uploads base64-encoded data from "base64file" to filename.
$g->base64_out ($filename, $base64file);
This command downloads the contents of filename, writing it out to local file
"base64file" encoded as base64.
$g->blkdiscard ($device);
This discards all blocks on the block device "device", giving the free space back to
the host.
This operation requires support in libguestfs, the host filesystem, qemu and the host
kernel. If this support isn't present it may give an error or even appear to run but
do nothing. You must also set the "discard" attribute on the underlying drive (see
"$g->add_drive_opts").
$zeroes = $g->blkdiscardzeroes ($device);
This call returns true if blocks on "device" that have been discarded by a call to
"$g->blkdiscard" are returned as blocks of zero bytes when read the next time.
If it returns false, then it may be that discarded blocks are read as stale or random
data.
%info = $g->blkid ($device);
This command returns block device attributes for "device". The following fields are
usually present in the returned hash. Other fields may also be present.
"UUID"
The uuid of this device.
"LABEL"
The label of this device.
"VERSION"
The version of blkid command.
"TYPE"
The filesystem type or RAID of this device.
"USAGE"
The usage of this device, for example "filesystem" or "raid".
$g->blockdev_flushbufs ($device);
This tells the kernel to flush internal buffers associated with "device".
This uses the blockdev(8) command.
$blocksize = $g->blockdev_getbsz ($device);
This returns the block size of a device.
Note: this is different from both size in blocks and filesystem block size. Also this
setting is not really used by anything. You should probably not use it for anything.
Filesystems have their own idea about what block size to choose.
This uses the blockdev(8) command.
$ro = $g->blockdev_getro ($device);
Returns a boolean indicating if the block device is read-only (true if read-only,
false if not).
This uses the blockdev(8) command.
$sizeinbytes = $g->blockdev_getsize64 ($device);
This returns the size of the device in bytes.
See also "$g->blockdev_getsz".
This uses the blockdev(8) command.
$sectorsize = $g->blockdev_getss ($device);
This returns the size of sectors on a block device. Usually 512, but can be larger
for modern devices.
(Note, this is not the size in sectors, use "$g->blockdev_getsz" for that).
This uses the blockdev(8) command.
$sizeinsectors = $g->blockdev_getsz ($device);
This returns the size of the device in units of 512-byte sectors (even if the
sectorsize isn't 512 bytes ... weird).
See also "$g->blockdev_getss" for the real sector size of the device, and
"$g->blockdev_getsize64" for the more useful size in bytes.
This uses the blockdev(8) command.
$g->blockdev_rereadpt ($device);
Reread the partition table on "device".
This uses the blockdev(8) command.
$g->blockdev_setbsz ($device, $blocksize);
This call does nothing and has never done anything because of a bug in blockdev. Do
not use it.
If you need to set the filesystem block size, use the "blocksize" option of
"$g->mkfs".
This function is deprecated. In new code, use the "mkfs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->blockdev_setra ($device, $sectors);
Set readahead (in 512-byte sectors) for the device.
This uses the blockdev(8) command.
$g->blockdev_setro ($device);
Sets the block device named "device" to read-only.
This uses the blockdev(8) command.
$g->blockdev_setrw ($device);
Sets the block device named "device" to read-write.
This uses the blockdev(8) command.
$g->btrfs_balance_cancel ($path);
Cancel a running balance on a btrfs filesystem.
$g->btrfs_balance_pause ($path);
Pause a running balance on a btrfs filesystem.
$g->btrfs_balance_resume ($path);
Resume a paused balance on a btrfs filesystem.
%status = $g->btrfs_balance_status ($path);
Show the status of a running or paused balance on a btrfs filesystem.
$g->btrfs_device_add (\@devices, $fs);
Add the list of device(s) in "devices" to the btrfs filesystem mounted at "fs". If
"devices" is an empty list, this does nothing.
$g->btrfs_device_delete (\@devices, $fs);
Remove the "devices" from the btrfs filesystem mounted at "fs". If "devices" is an
empty list, this does nothing.
$g->btrfs_filesystem_balance ($fs);
Balance the chunks in the btrfs filesystem mounted at "fs" across the underlying
devices.
$g->btrfs_filesystem_defragment ($path [, flush => $flush] [, compress => $compress]);
Defragment a file or directory on a btrfs filesystem. compress is one of zlib or lzo.
$g->btrfs_filesystem_resize ($mountpoint [, size => $size]);
This command resizes a btrfs filesystem.
Note that unlike other resize calls, the filesystem has to be mounted and the
parameter is the mountpoint not the device (this is a requirement of btrfs itself).
The optional parameters are:
"size"
The new size (in bytes) of the filesystem. If omitted, the filesystem is resized
to the maximum size.
See also btrfs(8).
$g->btrfs_filesystem_sync ($fs);
Force sync on the btrfs filesystem mounted at "fs".
$g->btrfs_fsck ($device [, superblock => $superblock] [, repair => $repair]);
Used to check a btrfs filesystem, "device" is the device file where the filesystem is
stored.
$g->btrfs_image (\@source, $image [, compresslevel => $compresslevel]);
This is used to create an image of a btrfs filesystem. All data will be zeroed, but
metadata and the like is preserved.
$g->btrfs_qgroup_assign ($src, $dst, $path);
Add qgroup "src" to parent qgroup "dst". This command can group several qgroups into a
parent qgroup to share common limit.
$g->btrfs_qgroup_create ($qgroupid, $subvolume);
Create a quota group (qgroup) for subvolume at "subvolume".
$g->btrfs_qgroup_destroy ($qgroupid, $subvolume);
Destroy a quota group.
$g->btrfs_qgroup_limit ($subvolume, $size);
Limit the size of a subvolume which's path is "subvolume". "size" can have suffix of
G, M, or K.
$g->btrfs_qgroup_remove ($src, $dst, $path);
Remove qgroup "src" from the parent qgroup "dst".
@qgroups = $g->btrfs_qgroup_show ($path);
Show all subvolume quota groups in a btrfs filesystem, including their usages.
$g->btrfs_quota_enable ($fs, $enable);
Enable or disable subvolume quota support for filesystem which contains "path".
$g->btrfs_quota_rescan ($fs);
Trash all qgroup numbers and scan the metadata again with the current config.
$g->btrfs_replace ($srcdev, $targetdev, $mntpoint);
Replace device of a btrfs filesystem. On a live filesystem, duplicate the data to the
target device which is currently stored on the source device. After completion of the
operation, the source device is wiped out and removed from the filesystem.
The "targetdev" needs to be same size or larger than the "srcdev". Devices which are
currently mounted are never allowed to be used as the "targetdev".
$g->btrfs_rescue_chunk_recover ($device);
Recover the chunk tree of btrfs filesystem by scanning the devices one by one.
$g->btrfs_rescue_super_recover ($device);
Recover bad superblocks from good copies.
$g->btrfs_scrub_cancel ($path);
Cancel a running scrub on a btrfs filesystem.
$g->btrfs_scrub_resume ($path);
Resume a previously canceled or interrupted scrub on a btrfs filesystem.
$g->btrfs_scrub_start ($path);
Reads all the data and metadata on the filesystem, and uses checksums and the
duplicate copies from RAID storage to identify and repair any corrupt data.
%status = $g->btrfs_scrub_status ($path);
Show status of running or finished scrub on a btrfs filesystem.
$g->btrfs_set_seeding ($device, $seeding);
Enable or disable the seeding feature of a device that contains a btrfs filesystem.
$g->btrfs_subvolume_create ($dest [, qgroupid => $qgroupid]);
Create a btrfs subvolume. The "dest" argument is the destination directory and the
name of the subvolume, in the form /path/to/dest/name. The optional parameter
"qgroupid" represents the qgroup which the newly created subvolume will be added to.
$g->btrfs_subvolume_create_opts ($dest [, qgroupid => $qgroupid]);
This is an alias of "btrfs_subvolume_create".
$g->btrfs_subvolume_delete ($subvolume);
Delete the named btrfs subvolume or snapshot.
$id = $g->btrfs_subvolume_get_default ($fs);
Get the default subvolume or snapshot of a filesystem mounted at "mountpoint".
@subvolumes = $g->btrfs_subvolume_list ($fs);
List the btrfs snapshots and subvolumes of the btrfs filesystem which is mounted at
"fs".
$g->btrfs_subvolume_set_default ($id, $fs);
Set the subvolume of the btrfs filesystem "fs" which will be mounted by default. See
"$g->btrfs_subvolume_list" to get a list of subvolumes.
%btrfssubvolumeinfo = $g->btrfs_subvolume_show ($subvolume);
Return detailed information of the subvolume.
$g->btrfs_subvolume_snapshot ($source, $dest [, ro => $ro] [, qgroupid => $qgroupid]);
Create a snapshot of the btrfs subvolume "source". The "dest" argument is the
destination directory and the name of the snapshot, in the form /path/to/dest/name. By
default the newly created snapshot is writable, if the value of optional parameter
"ro" is true, then a readonly snapshot is created. The optional parameter "qgroupid"
represents the qgroup which the newly created snapshot will be added to.
$g->btrfs_subvolume_snapshot_opts ($source, $dest [, ro => $ro] [, qgroupid =>
$qgroupid]);
This is an alias of "btrfs_subvolume_snapshot".
$g->btrfstune_enable_extended_inode_refs ($device);
This will Enable extended inode refs.
$g->btrfstune_enable_skinny_metadata_extent_refs ($device);
This enable skinny metadata extent refs.
$g->btrfstune_seeding ($device, $seeding);
Enable seeding of a btrfs device, this will force a fs readonly so that you can use it
to build other filesystems.
$ptr = $g->c_pointer ();
In non-C language bindings, this allows you to retrieve the underlying C pointer to
the handle (ie. "$g->h *"). The purpose of this is to allow other libraries to
interwork with libguestfs.
$canonical = $g->canonical_device_name ($device);
This utility function is useful when displaying device names to the user. It takes a
number of irregular device names and returns them in a consistent format:
/dev/hdX
/dev/vdX
These are returned as /dev/sdX. Note this works for device names and partition
names. This is approximately the reverse of the algorithm described in "BLOCK
DEVICE NAMING" in guestfs(3).
/dev/mapper/VG-LV
/dev/dm-N
Converted to /dev/VG/LV form using "$g->lvm_canonical_lv_name".
Other strings are returned unmodified.
$cap = $g->cap_get_file ($path);
This function returns the Linux capabilities attached to "path". The capabilities set
is returned in text form (see cap_to_text(3)).
If no capabilities are attached to a file, an empty string is returned.
$g->cap_set_file ($path, $cap);
This function sets the Linux capabilities attached to "path". The capabilities set
"cap" should be passed in text form (see cap_from_text(3)).
$rpath = $g->case_sensitive_path ($path);
This can be used to resolve case insensitive paths on a filesystem which is case
sensitive. The use case is to resolve paths which you have read from Windows
configuration files or the Windows Registry, to the true path.
The command handles a peculiarity of the Linux ntfs-3g filesystem driver (and probably
others), which is that although the underlying filesystem is case-insensitive, the
driver exports the filesystem to Linux as case-sensitive.
One consequence of this is that special directories such as C:\windows may appear as
/WINDOWS or /windows (or other things) depending on the precise details of how they
were created. In Windows itself this would not be a problem.
Bug or feature? You decide:
<http://www.tuxera.com/community/ntfs-3g-faq/#posixfilenames1>
"$g->case_sensitive_path" attempts to resolve the true case of each element in the
path. It will return a resolved path if either the full path or its parent directory
exists. If the parent directory exists but the full path does not, the case of the
parent directory will be correctly resolved, and the remainder appended unmodified.
For example, if the file "/Windows/System32/netkvm.sys" exists:
"$g->case_sensitive_path" ("/windows/system32/netkvm.sys")
"Windows/System32/netkvm.sys"
"$g->case_sensitive_path" ("/windows/system32/NoSuchFile")
"Windows/System32/NoSuchFile"
"$g->case_sensitive_path" ("/windows/system33/netkvm.sys")
ERROR
Note: Because of the above behaviour, "$g->case_sensitive_path" cannot be used to
check for the existence of a file.
Note: This function does not handle drive names, backslashes etc.
See also "$g->realpath".
$content = $g->cat ($path);
Return the contents of the file named "path".
Because, in C, this function returns a "char *", there is no way to differentiate
between a "\0" character in a file and end of string. To handle binary files, use the
"$g->read_file" or "$g->download" functions.
$checksum = $g->checksum ($csumtype, $path);
This call computes the MD5, SHAx or CRC checksum of the file named "path".
The type of checksum to compute is given by the "csumtype" parameter which must have
one of the following values:
"crc"
Compute the cyclic redundancy check (CRC) specified by POSIX for the "cksum"
command.
"md5"
Compute the MD5 hash (using the "md5sum" program).
"sha1"
Compute the SHA1 hash (using the "sha1sum" program).
"sha224"
Compute the SHA224 hash (using the "sha224sum" program).
"sha256"
Compute the SHA256 hash (using the "sha256sum" program).
"sha384"
Compute the SHA384 hash (using the "sha384sum" program).
"sha512"
Compute the SHA512 hash (using the "sha512sum" program).
The checksum is returned as a printable string.
To get the checksum for a device, use "$g->checksum_device".
To get the checksums for many files, use "$g->checksums_out".
$checksum = $g->checksum_device ($csumtype, $device);
This call computes the MD5, SHAx or CRC checksum of the contents of the device named
"device". For the types of checksums supported see the "$g->checksum" command.
$g->checksums_out ($csumtype, $directory, $sumsfile);
This command computes the checksums of all regular files in directory and then emits a
list of those checksums to the local output file "sumsfile".
This can be used for verifying the integrity of a virtual machine. However to be
properly secure you should pay attention to the output of the checksum command (it
uses the ones from GNU coreutils). In particular when the filename is not printable,
coreutils uses a special backslash syntax. For more information, see the GNU
coreutils info file.
$g->chmod ($mode, $path);
Change the mode (permissions) of "path" to "mode". Only numeric modes are supported.
Note: When using this command from guestfish, "mode" by default would be decimal,
unless you prefix it with 0 to get octal, ie. use 0700 not 700.
The mode actually set is affected by the umask.
$g->chown ($owner, $group, $path);
Change the file owner to "owner" and group to "group".
Only numeric uid and gid are supported. If you want to use names, you will need to
locate and parse the password file yourself (Augeas support makes this relatively
easy).
$count = $g->clear_backend_setting ($name);
If there is a backend setting string matching "name" or beginning with "name=", then
that string is removed from the backend settings.
This call returns the number of strings which were removed (which may be 0, 1 or
greater than 1).
See "BACKEND" in guestfs(3), "BACKEND SETTINGS" in guestfs(3).
$output = $g->command (\@arguments);
This call runs a command from the guest filesystem. The filesystem must be mounted,
and must contain a compatible operating system (ie. something Linux, with the same or
compatible processor architecture).
The single parameter is an argv-style list of arguments. The first element is the
name of the program to run. Subsequent elements are parameters. The list must be
non-empty (ie. must contain a program name). Note that the command runs directly, and
is not invoked via the shell (see "$g->sh").
The return value is anything printed to stdout by the command.
If the command returns a non-zero exit status, then this function returns an error
message. The error message string is the content of stderr from the command.
The $PATH environment variable will contain at least /usr/bin and /bin. If you
require a program from another location, you should provide the full path in the first
parameter.
Shared libraries and data files required by the program must be available on
filesystems which are mounted in the correct places. It is the caller's
responsibility to ensure all filesystems that are needed are mounted at the right
locations.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
@lines = $g->command_lines (\@arguments);
This is the same as "$g->command", but splits the result into a list of lines.
See also: "$g->sh_lines"
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$g->compress_device_out ($ctype, $device, $zdevice [, level => $level]);
This command compresses "device" and writes it out to the local file "zdevice".
The "ctype" and optional "level" parameters have the same meaning as in
"$g->compress_out".
$g->compress_out ($ctype, $file, $zfile [, level => $level]);
This command compresses file and writes it out to the local file zfile.
The compression program used is controlled by the "ctype" parameter. Currently this
includes: "compress", "gzip", "bzip2", "xz" or "lzop". Some compression types may not
be supported by particular builds of libguestfs, in which case you will get an error
containing the substring "not supported".
The optional "level" parameter controls compression level. The meaning and default
for this parameter depends on the compression program being used.
$g->config ($hvparam, $hvvalue);
This can be used to add arbitrary hypervisor parameters of the form -param value.
Actually it's not quite arbitrary - we prevent you from setting some parameters which
would interfere with parameters that we use.
The first character of "hvparam" string must be a "-" (dash).
"hvvalue" can be NULL.
$g->copy_attributes ($src, $dest [, all => $all] [, mode => $mode] [, xattributes =>
$xattributes] [, ownership => $ownership]);
Copy the attributes of a path (which can be a file or a directory) to another path.
By default "no" attribute is copied, so make sure to specify any (or "all" to copy
everything).
The optional arguments specify which attributes can be copied:
"mode"
Copy part of the file mode from "source" to "destination". Only the UNIX
permissions and the sticky/setuid/setgid bits can be copied.
"xattributes"
Copy the Linux extended attributes (xattrs) from "source" to "destination". This
flag does nothing if the linuxxattrs feature is not available (see
"$g->feature_available").
"ownership"
Copy the owner uid and the group gid of "source" to "destination".
"all"
Copy all the attributes from "source" to "destination". Enabling it enables all
the other flags, if they are not specified already.
$g->copy_device_to_device ($src, $dest [, srcoffset => $srcoffset] [, destoffset =>
$destoffset] [, size => $size] [, sparse => $sparse] [, append => $append]);
The four calls "$g->copy_device_to_device", "$g->copy_device_to_file",
"$g->copy_file_to_device", and "$g->copy_file_to_file" let you copy from a source
(device|file) to a destination (device|file).
Partial copies can be made since you can specify optionally the source offset,
destination offset and size to copy. These values are all specified in bytes. If not
given, the offsets both default to zero, and the size defaults to copying as much as
possible until we hit the end of the source.
The source and destination may be the same object. However overlapping regions may
not be copied correctly.
If the destination is a file, it is created if required. If the destination file is
not large enough, it is extended.
If the destination is a file and the "append" flag is not set, then the destination
file is truncated. If the "append" flag is set, then the copy appends to the
destination file. The "append" flag currently cannot be set for devices.
If the "sparse" flag is true then the call avoids writing blocks that contain only
zeroes, which can help in some situations where the backing disk is thin-provisioned.
Note that unless the target is already zeroed, using this option will result in
incorrect copying.
$g->copy_device_to_file ($src, $dest [, srcoffset => $srcoffset] [, destoffset =>
$destoffset] [, size => $size] [, sparse => $sparse] [, append => $append]);
See "$g->copy_device_to_device" for a general overview of this call.
$g->copy_file_to_device ($src, $dest [, srcoffset => $srcoffset] [, destoffset =>
$destoffset] [, size => $size] [, sparse => $sparse] [, append => $append]);
See "$g->copy_device_to_device" for a general overview of this call.
$g->copy_file_to_file ($src, $dest [, srcoffset => $srcoffset] [, destoffset =>
$destoffset] [, size => $size] [, sparse => $sparse] [, append => $append]);
See "$g->copy_device_to_device" for a general overview of this call.
This is not the function you want for copying files. This is for copying blocks
within existing files. See "$g->cp", "$g->cp_a" and "$g->mv" for general file copying
and moving functions.
$g->copy_in ($localpath, $remotedir);
"$g->copy_in" copies local files or directories recursively into the disk image,
placing them in the directory called "remotedir" (which must exist).
Wildcards cannot be used.
$g->copy_out ($remotepath, $localdir);
"$g->copy_out" copies remote files or directories recursively out of the disk image,
placing them on the host disk in a local directory called "localdir" (which must
exist).
To download to the current directory, use "." as in:
C<$g-E<gt>copy_out> /home .
Wildcards cannot be used.
$g->copy_size ($src, $dest, $size);
This command copies exactly "size" bytes from one source device or file "src" to
another destination device or file "dest".
Note this will fail if the source is too short or if the destination is not large
enough.
This function is deprecated. In new code, use the "copy_device_to_device" call
instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->cp ($src, $dest);
This copies a file from "src" to "dest" where "dest" is either a destination filename
or destination directory.
$g->cp_a ($src, $dest);
This copies a file or directory from "src" to "dest" recursively using the "cp -a"
command.
$g->cp_r ($src, $dest);
This copies a file or directory from "src" to "dest" recursively using the "cp -rP"
command.
Most users should use "$g->cp_a" instead. This command is useful when you don't want
to preserve permissions, because the target filesystem does not support it (primarily
when writing to DOS FAT filesystems).
$g->cpio_out ($directory, $cpiofile [, format => $format]);
This command packs the contents of directory and downloads it to local file
"cpiofile".
The optional "format" parameter can be used to select the format. Only the following
formats are currently permitted:
"newc"
New (SVR4) portable format. This format happens to be compatible with the cpio-
like format used by the Linux kernel for initramfs.
This is the default format.
"crc"
New (SVR4) portable format with a checksum.
$g->dd ($src, $dest);
This command copies from one source device or file "src" to another destination device
or file "dest". Normally you would use this to copy to or from a device or partition,
for example to duplicate a filesystem.
If the destination is a device, it must be as large or larger than the source file or
device, otherwise the copy will fail. This command cannot do partial copies (see
"$g->copy_device_to_device").
This function is deprecated. In new code, use the "copy_device_to_device" call
instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$index = $g->device_index ($device);
This function takes a device name (eg. "/dev/sdb") and returns the index of the device
in the list of devices.
Index numbers start from 0. The named device must exist, for example as a string
returned from "$g->list_devices".
See also "$g->list_devices", "$g->part_to_dev".
$output = $g->df ();
This command runs the "df" command to report disk space used.
This command is mostly useful for interactive sessions. It is not intended that you
try to parse the output string. Use "$g->statvfs" from programs.
$output = $g->df_h ();
This command runs the "df -h" command to report disk space used in human-readable
format.
This command is mostly useful for interactive sessions. It is not intended that you
try to parse the output string. Use "$g->statvfs" from programs.
$g->disk_create ($filename, $format, $size [, backingfile => $backingfile] [,
backingformat => $backingformat] [, preallocation => $preallocation] [, compat => $compat]
[, clustersize => $clustersize]);
Create a blank disk image called filename (a host file) with format "format" (usually
"raw" or "qcow2"). The size is "size" bytes.
If used with the optional "backingfile" parameter, then a snapshot is created on top
of the backing file. In this case, "size" must be passed as "-1". The size of the
snapshot is the same as the size of the backing file, which is discovered
automatically. You are encouraged to also pass "backingformat" to describe the format
of "backingfile".
If filename refers to a block device, then the device is formatted. The "size" is
ignored since block devices have an intrinsic size.
The other optional parameters are:
"preallocation"
If format is "raw", then this can be either "off" (or "sparse") or "full" to
create a sparse or fully allocated file respectively. The default is "off".
If format is "qcow2", then this can be "off" (or "sparse"), "metadata" or "full".
Preallocating metadata can be faster when doing lots of writes, but uses more
space. The default is "off".
"compat"
"qcow2" only: Pass the string 1.1 to use the advanced qcow2 format supported by
qemu X 1.1.
"clustersize"
"qcow2" only: Change the qcow2 cluster size. The default is 65536 (bytes) and
this setting may be any power of two between 512 and 2097152.
Note that this call does not add the new disk to the handle. You may need to call
"$g->add_drive_opts" separately.
$format = $g->disk_format ($filename);
Detect and return the format of the disk image called filename. filename can also be
a host device, etc. If the format of the image could not be detected, then "unknown"
is returned.
Note that detecting the disk format can be insecure under some circumstances. See
"CVE-2010-3851" in guestfs(3).
See also: "DISK IMAGE FORMATS" in guestfs(3)
$backingfile = $g->disk_has_backing_file ($filename);
Detect and return whether the disk image filename has a backing file.
Note that detecting disk features can be insecure under some circumstances. See
"CVE-2010-3851" in guestfs(3).
$size = $g->disk_virtual_size ($filename);
Detect and return the virtual size in bytes of the disk image called filename.
Note that detecting disk features can be insecure under some circumstances. See
"CVE-2010-3851" in guestfs(3).
$kmsgs = $g->dmesg ();
This returns the kernel messages ("dmesg" output) from the guest kernel. This is
sometimes useful for extended debugging of problems.
Another way to get the same information is to enable verbose messages with
"$g->set_verbose" or by setting the environment variable "LIBGUESTFS_DEBUG=1" before
running the program.
$g->download ($remotefilename, $filename);
Download file remotefilename and save it as filename on the local machine.
filename can also be a named pipe.
See also "$g->upload", "$g->cat".
$g->download_offset ($remotefilename, $filename, $offset, $size);
Download file remotefilename and save it as filename on the local machine.
remotefilename is read for "size" bytes starting at "offset" (this region must be
within the file or device).
Note that there is no limit on the amount of data that can be downloaded with this
call, unlike with "$g->pread", and this call always reads the full amount unless an
error occurs.
See also "$g->download", "$g->pread".
$g->drop_caches ($whattodrop);
This instructs the guest kernel to drop its page cache, and/or dentries and inode
caches. The parameter "whattodrop" tells the kernel what precisely to drop, see
<http://linux-mm.org/Drop_Caches>
Setting "whattodrop" to 3 should drop everything.
This automatically calls sync(2) before the operation, so that the maximum guest
memory is freed.
$sizekb = $g->du ($path);
This command runs the "du -s" command to estimate file space usage for "path".
"path" can be a file or a directory. If "path" is a directory then the estimate
includes the contents of the directory and all subdirectories (recursively).
The result is the estimated size in kilobytes (ie. units of 1024 bytes).
$g->e2fsck ($device [, correct => $correct] [, forceall => $forceall]);
This runs the ext2/ext3 filesystem checker on "device". It can take the following
optional arguments:
"correct"
Automatically repair the file system. This option will cause e2fsck to
automatically fix any filesystem problems that can be safely fixed without human
intervention.
This option may not be specified at the same time as the "forceall" option.
"forceall"
Assume an answer of 'yes' to all questions; allows e2fsck to be used non-
interactively.
This option may not be specified at the same time as the "correct" option.
$g->e2fsck_f ($device);
This runs "e2fsck -p -f device", ie. runs the ext2/ext3 filesystem checker on
"device", noninteractively (-p), even if the filesystem appears to be clean (-f).
This function is deprecated. In new code, use the "e2fsck" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$output = $g->echo_daemon (\@words);
This command concatenates the list of "words" passed with single spaces between them
and returns the resulting string.
You can use this command to test the connection through to the daemon.
See also "$g->ping_daemon".
@lines = $g->egrep ($regex, $path);
This calls the external "egrep" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@lines = $g->egrepi ($regex, $path);
This calls the external "egrep -i" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$equality = $g->equal ($file1, $file2);
This compares the two files file1 and file2 and returns true if their content is
exactly equal, or false otherwise.
The external cmp(1) program is used for the comparison.
$existsflag = $g->exists ($path);
This returns "true" if and only if there is a file, directory (or anything) with the
given "path" name.
See also "$g->is_file", "$g->is_dir", "$g->stat".
$g->extlinux ($directory);
Install the SYSLINUX bootloader on the device mounted at directory. Unlike
"$g->syslinux" which requires a FAT filesystem, this can be used on an ext2/3/4 or
btrfs filesystem.
The directory parameter can be either a mountpoint, or a directory within the
mountpoint.
You also have to mark the partition as "active" ("$g->part_set_bootable") and a Master
Boot Record must be installed (eg. using "$g->pwrite_device") on the first sector of
the whole disk. The SYSLINUX package comes with some suitable Master Boot Records.
See the extlinux(1) man page for further information.
Additional configuration can be supplied to SYSLINUX by placing a file called
extlinux.conf on the filesystem under directory. For further information about the
contents of this file, see extlinux(1).
See also "$g->syslinux".
$g->fallocate ($path, $len);
This command preallocates a file (containing zero bytes) named "path" of size "len"
bytes. If the file exists already, it is overwritten.
Do not confuse this with the guestfish-specific "alloc" command which allocates a file
in the host and attaches it as a device.
This function is deprecated. In new code, use the "fallocate64" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->fallocate64 ($path, $len);
This command preallocates a file (containing zero bytes) named "path" of size "len"
bytes. If the file exists already, it is overwritten.
Note that this call allocates disk blocks for the file. To create a sparse file use
"$g->truncate_size" instead.
The deprecated call "$g->fallocate" does the same, but owing to an oversight it only
allowed 30 bit lengths to be specified, effectively limiting the maximum size of files
created through that call to 1GB.
Do not confuse this with the guestfish-specific "alloc" and "sparse" commands which
create a file in the host and attach it as a device.
$isavailable = $g->feature_available (\@groups);
This is the same as "$g->available", but unlike that call it returns a simple
true/false boolean result, instead of throwing an exception if a feature is not found.
For other documentation see "$g->available".
@lines = $g->fgrep ($pattern, $path);
This calls the external "fgrep" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@lines = $g->fgrepi ($pattern, $path);
This calls the external "fgrep -i" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$description = $g->file ($path);
This call uses the standard file(1) command to determine the type or contents of the
file.
This call will also transparently look inside various types of compressed file.
The exact command which runs is "file -zb path". Note in particular that the filename
is not prepended to the output (the -b option).
The output depends on the output of the underlying file(1) command and it can change
in future in ways beyond our control. In other words, the output is not guaranteed by
the ABI.
See also: file(1), "$g->vfs_type", "$g->lstat", "$g->is_file", "$g->is_blockdev"
(etc), "$g->is_zero".
$arch = $g->file_architecture ($filename);
This detects the architecture of the binary filename, and returns it if known.
Currently defined architectures are:
"i386"
This string is returned for all 32 bit i386, i486, i586, i686 binaries
irrespective of the precise processor requirements of the binary.
"x86_64"
64 bit x86-64.
"sparc"
32 bit SPARC.
"sparc64"
64 bit SPARC V9 and above.
"ia64"
Intel Itanium.
"ppc"
32 bit Power PC.
"ppc64"
64 bit Power PC.
"arm"
32 bit ARM.
"aarch64"
64 bit ARM.
Libguestfs may return other architecture strings in future.
The function works on at least the following types of files:
• many types of Un*x and Linux binary
• many types of Un*x and Linux shared library
• Windows Win32 and Win64 binaries
• Windows Win32 and Win64 DLLs
Win32 binaries and DLLs return "i386".
Win64 binaries and DLLs return "x86_64".
• Linux kernel modules
• Linux new-style initrd images
• some non-x86 Linux vmlinuz kernels
What it can't do currently:
• static libraries (libfoo.a)
• Linux old-style initrd as compressed ext2 filesystem (RHEL 3)
• x86 Linux vmlinuz kernels
x86 vmlinuz images (bzImage format) consist of a mix of 16-, 32- and compressed
code, and are horribly hard to unpack. If you want to find the architecture of a
kernel, use the architecture of the associated initrd or kernel module(s) instead.
$size = $g->filesize ($file);
This command returns the size of file in bytes.
To get other stats about a file, use "$g->stat", "$g->lstat", "$g->is_dir",
"$g->is_file" etc. To get the size of block devices, use "$g->blockdev_getsize64".
$fsavail = $g->filesystem_available ($filesystem);
Check whether libguestfs supports the named filesystem. The argument "filesystem" is
a filesystem name, such as "ext3".
You must call "$g->launch" before using this command.
This is mainly useful as a negative test. If this returns true, it doesn't mean that
a particular filesystem can be created or mounted, since filesystems can fail for
other reasons such as it being a later version of the filesystem, or having
incompatible features, or lacking the right mkfs.<fs> tool.
See also "$g->available", "$g->feature_available", "AVAILABILITY" in guestfs(3).
$g->fill ($c, $len, $path);
This command creates a new file called "path". The initial content of the file is
"len" octets of "c", where "c" must be a number in the range "[0..255]".
To fill a file with zero bytes (sparsely), it is much more efficient to use
"$g->truncate_size". To create a file with a pattern of repeating bytes use
"$g->fill_pattern".
$g->fill_dir ($dir, $nr);
This function, useful for testing filesystems, creates "nr" empty files in the
directory "dir" with names 00000000 through "nr-1" (ie. each file name is 8 digits
long padded with zeroes).
$g->fill_pattern ($pattern, $len, $path);
This function is like "$g->fill" except that it creates a new file of length "len"
containing the repeating pattern of bytes in "pattern". The pattern is truncated if
necessary to ensure the length of the file is exactly "len" bytes.
@names = $g->find ($directory);
This command lists out all files and directories, recursively, starting at directory.
It is essentially equivalent to running the shell command "find directory -print" but
some post-processing happens on the output, described below.
This returns a list of strings without any prefix. Thus if the directory structure
was:
/tmp/a
/tmp/b
/tmp/c/d
then the returned list from "$g->find" /tmp would be 4 elements:
a
b
c
c/d
If directory is not a directory, then this command returns an error.
The returned list is sorted.
$g->find0 ($directory, $files);
This command lists out all files and directories, recursively, starting at directory,
placing the resulting list in the external file called files.
This command works the same way as "$g->find" with the following exceptions:
• The resulting list is written to an external file.
• Items (filenames) in the result are separated by "\0" characters. See find(1)
option -print0.
• The result list is not sorted.
$device = $g->findfs_label ($label);
This command searches the filesystems and returns the one which has the given label.
An error is returned if no such filesystem can be found.
To find the label of a filesystem, use "$g->vfs_label".
$device = $g->findfs_uuid ($uuid);
This command searches the filesystems and returns the one which has the given UUID.
An error is returned if no such filesystem can be found.
To find the UUID of a filesystem, use "$g->vfs_uuid".
$status = $g->fsck ($fstype, $device);
This runs the filesystem checker (fsck) on "device" which should have filesystem type
"fstype".
The returned integer is the status. See fsck(8) for the list of status codes from
"fsck".
Notes:
• Multiple status codes can be summed together.
• A non-zero return code can mean "success", for example if errors have been
corrected on the filesystem.
• Checking or repairing NTFS volumes is not supported (by linux-ntfs).
This command is entirely equivalent to running "fsck -a -t fstype device".
$g->fstrim ($mountpoint [, offset => $offset] [, length => $length] [, minimumfreeextent
=> $minimumfreeextent]);
Trim the free space in the filesystem mounted on "mountpoint". The filesystem must be
mounted read-write.
The filesystem contents are not affected, but any free space in the filesystem is
"trimmed", that is, given back to the host device, thus making disk images more
sparse, allowing unused space in qcow2 files to be reused, etc.
This operation requires support in libguestfs, the mounted filesystem, the host
filesystem, qemu and the host kernel. If this support isn't present it may give an
error or even appear to run but do nothing.
See also "$g->zero_free_space". That is a slightly different operation that turns
free space in the filesystem into zeroes. It is valid to call "$g->fstrim" either
instead of, or after calling "$g->zero_free_space".
$append = $g->get_append ();
Return the additional kernel options which are added to the libguestfs appliance
kernel command line.
If "NULL" then no options are added.
$backend = $g->get_attach_method ();
Return the current backend.
See "$g->set_backend" and "BACKEND" in guestfs(3).
This function is deprecated. In new code, use the "get_backend" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$autosync = $g->get_autosync ();
Get the autosync flag.
$backend = $g->get_backend ();
Return the current backend.
This handle property was previously called the "attach method".
See "$g->set_backend" and "BACKEND" in guestfs(3).
$val = $g->get_backend_setting ($name);
Find a backend setting string which is either "name" or begins with "name=". If
"name", this returns the string "1". If "name=", this returns the part after the
equals sign (which may be an empty string).
If no such setting is found, this function throws an error. The errno (see
"$g->last_errno") will be "ESRCH" in this case.
See "BACKEND" in guestfs(3), "BACKEND SETTINGS" in guestfs(3).
@settings = $g->get_backend_settings ();
Return the current backend settings.
This call returns all backend settings strings. If you want to find a single backend
setting, see "$g->get_backend_setting".
See "BACKEND" in guestfs(3), "BACKEND SETTINGS" in guestfs(3).
$cachedir = $g->get_cachedir ();
Get the directory used by the handle to store the appliance cache.
$direct = $g->get_direct ();
Return the direct appliance mode flag.
$attrs = $g->get_e2attrs ($file);
This returns the file attributes associated with file.
The attributes are a set of bits associated with each inode which affect the behaviour
of the file. The attributes are returned as a string of letters (described below).
The string may be empty, indicating that no file attributes are set for this file.
These attributes are only present when the file is located on an ext2/3/4 filesystem.
Using this call on other filesystem types will result in an error.
The characters (file attributes) in the returned string are currently:
'A' When the file is accessed, its atime is not modified.
'a' The file is append-only.
'c' The file is compressed on-disk.
'D' (Directories only.) Changes to this directory are written synchronously to disk.
'd' The file is not a candidate for backup (see dump(8)).
'E' The file has compression errors.
'e' The file is using extents.
'h' The file is storing its blocks in units of the filesystem blocksize instead of
sectors.
'I' (Directories only.) The directory is using hashed trees.
'i' The file is immutable. It cannot be modified, deleted or renamed. No link can be
created to this file.
'j' The file is data-journaled.
's' When the file is deleted, all its blocks will be zeroed.
'S' Changes to this file are written synchronously to disk.
'T' (Directories only.) This is a hint to the block allocator that subdirectories
contained in this directory should be spread across blocks. If not present, the
block allocator will try to group subdirectories together.
't' For a file, this disables tail-merging. (Not used by upstream implementations of
ext2.)
'u' When the file is deleted, its blocks will be saved, allowing the file to be
undeleted.
'X' The raw contents of the compressed file may be accessed.
'Z' The compressed file is dirty.
More file attributes may be added to this list later. Not all file attributes may be
set for all kinds of files. For detailed information, consult the chattr(1) man page.
See also "$g->set_e2attrs".
Don't confuse these attributes with extended attributes (see "$g->getxattr").
$generation = $g->get_e2generation ($file);
This returns the ext2 file generation of a file. The generation (which used to be
called the "version") is a number associated with an inode. This is most commonly
used by NFS servers.
The generation is only present when the file is located on an ext2/3/4 filesystem.
Using this call on other filesystem types will result in an error.
See "$g->set_e2generation".
$label = $g->get_e2label ($device);
This returns the ext2/3/4 filesystem label of the filesystem on "device".
This function is deprecated. In new code, use the "vfs_label" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$uuid = $g->get_e2uuid ($device);
This returns the ext2/3/4 filesystem UUID of the filesystem on "device".
This function is deprecated. In new code, use the "vfs_uuid" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$hv = $g->get_hv ();
Return the current hypervisor binary.
This is always non-NULL. If it wasn't set already, then this will return the default
qemu binary name.
$identifier = $g->get_identifier ();
Get the handle identifier. See "$g->set_identifier".
$challenge = $g->get_libvirt_requested_credential_challenge ($index);
Get the challenge (provided by libvirt) for the "index"'th requested credential. If
libvirt did not provide a challenge, this returns the empty string "".
See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.
$defresult = $g->get_libvirt_requested_credential_defresult ($index);
Get the default result (provided by libvirt) for the "index"'th requested credential.
If libvirt did not provide a default result, this returns the empty string "".
See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.
$prompt = $g->get_libvirt_requested_credential_prompt ($index);
Get the prompt (provided by libvirt) for the "index"'th requested credential. If
libvirt did not provide a prompt, this returns the empty string "".
See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.
@creds = $g->get_libvirt_requested_credentials ();
This should only be called during the event callback for events of type
"GUESTFS_EVENT_LIBVIRT_AUTH".
Return the list of credentials requested by libvirt. Possible values are a subset of
the strings provided when you called "$g->set_libvirt_supported_credentials".
See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.
$memsize = $g->get_memsize ();
This gets the memory size in megabytes allocated to the hypervisor.
If "$g->set_memsize" was not called on this handle, and if "LIBGUESTFS_MEMSIZE" was
not set, then this returns the compiled-in default value for memsize.
For more information on the architecture of libguestfs, see guestfs(3).
$network = $g->get_network ();
This returns the enable network flag.
$path = $g->get_path ();
Return the current search path.
This is always non-NULL. If it wasn't set already, then this will return the default
path.
$pgroup = $g->get_pgroup ();
This returns the process group flag.
$pid = $g->get_pid ();
Return the process ID of the hypervisor. If there is no hypervisor running, then this
will return an error.
This is an internal call used for debugging and testing.
$program = $g->get_program ();
Get the program name. See "$g->set_program".
$hv = $g->get_qemu ();
Return the current hypervisor binary (usually qemu).
This is always non-NULL. If it wasn't set already, then this will return the default
qemu binary name.
This function is deprecated. In new code, use the "get_hv" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$recoveryproc = $g->get_recovery_proc ();
Return the recovery process enabled flag.
$selinux = $g->get_selinux ();
This returns the current setting of the selinux flag which is passed to the appliance
at boot time. See "$g->set_selinux".
For more information on the architecture of libguestfs, see guestfs(3).
$smp = $g->get_smp ();
This returns the number of virtual CPUs assigned to the appliance.
$state = $g->get_state ();
This returns the current state as an opaque integer. This is only useful for printing
debug and internal error messages.
For more information on states, see guestfs(3).
$tmpdir = $g->get_tmpdir ();
Get the directory used by the handle to store temporary files.
$trace = $g->get_trace ();
Return the command trace flag.
$mask = $g->get_umask ();
Return the current umask. By default the umask is 022 unless it has been set by
calling "$g->umask".
$verbose = $g->get_verbose ();
This returns the verbose messages flag.
$context = $g->getcon ();
This gets the SELinux security context of the daemon.
See the documentation about SELINUX in guestfs(3), and "$g->setcon"
$xattr = $g->getxattr ($path, $name);
Get a single extended attribute from file "path" named "name". This call follows
symlinks. If you want to lookup an extended attribute for the symlink itself, use
"$g->lgetxattr".
Normally it is better to get all extended attributes from a file in one go by calling
"$g->getxattrs". However some Linux filesystem implementations are buggy and do not
provide a way to list out attributes. For these filesystems (notably ntfs-3g) you
have to know the names of the extended attributes you want in advance and call this
function.
Extended attribute values are blobs of binary data. If there is no extended attribute
named "name", this returns an error.
See also: "$g->getxattrs", "$g->lgetxattr", attr(5).
@xattrs = $g->getxattrs ($path);
This call lists the extended attributes of the file or directory "path".
At the system call level, this is a combination of the listxattr(2) and getxattr(2)
calls.
See also: "$g->lgetxattrs", attr(5).
@paths = $g->glob_expand ($pattern);
This command searches for all the pathnames matching "pattern" according to the
wildcard expansion rules used by the shell.
If no paths match, then this returns an empty list (note: not an error).
It is just a wrapper around the C glob(3) function with flags "GLOB_MARK|GLOB_BRACE".
See that manual page for more details.
Notice that there is no equivalent command for expanding a device name (eg. /dev/sd*).
Use "$g->list_devices", "$g->list_partitions" etc functions instead.
@lines = $g->grep ($regex, $path [, extended => $extended] [, fixed => $fixed] [,
insensitive => $insensitive] [, compressed => $compressed]);
This calls the external "grep" program and returns the matching lines.
The optional flags are:
"extended"
Use extended regular expressions. This is the same as using the -E flag.
"fixed"
Match fixed (don't use regular expressions). This is the same as using the -F
flag.
"insensitive"
Match case-insensitive. This is the same as using the -i flag.
"compressed"
Use "zgrep" instead of "grep". This allows the input to be compress- or gzip-
compressed.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
@lines = $g->grep_opts ($regex, $path [, extended => $extended] [, fixed => $fixed] [,
insensitive => $insensitive] [, compressed => $compressed]);
This is an alias of "grep".
@lines = $g->grepi ($regex, $path);
This calls the external "grep -i" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->grub_install ($root, $device);
This command installs GRUB 1 (the Grand Unified Bootloader) on "device", with the root
directory being "root".
Notes:
• There is currently no way in the API to install grub2, which is used by most
modern Linux guests. It is possible to run the grub2 command from the guest,
although see the caveats in "RUNNING COMMANDS" in guestfs(3).
• This uses "grub-install" from the host. Unfortunately grub is not always
compatible with itself, so this only works in rather narrow circumstances.
Careful testing with each guest version is advisable.
• If grub-install reports the error "No suitable drive was found in the generated
device map." it may be that you need to create a /boot/grub/device.map file first
that contains the mapping between grub device names and Linux device names. It is
usually sufficient to create a file containing:
(hd0) /dev/vda
replacing /dev/vda with the name of the installation device.
@lines = $g->head ($path);
This command returns up to the first 10 lines of a file as a list of strings.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
@lines = $g->head_n ($nrlines, $path);
If the parameter "nrlines" is a positive number, this returns the first "nrlines"
lines of the file "path".
If the parameter "nrlines" is a negative number, this returns lines from the file
"path", excluding the last "nrlines" lines.
If the parameter "nrlines" is zero, this returns an empty list.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$dump = $g->hexdump ($path);
This runs "hexdump -C" on the given "path". The result is the human-readable,
canonical hex dump of the file.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$g->hivex_close ();
Close the current hivex handle.
This is a wrapper around the hivex(3) call of the same name.
$g->hivex_commit ($filename);
Commit (write) changes to the hive.
If the optional filename parameter is null, then the changes are written back to the
same hive that was opened. If this is not null then they are written to the alternate
filename given and the original hive is left untouched.
This is a wrapper around the hivex(3) call of the same name.
$nodeh = $g->hivex_node_add_child ($parent, $name);
Add a child node to "parent" named "name".
This is a wrapper around the hivex(3) call of the same name.
@nodehs = $g->hivex_node_children ($nodeh);
Return the list of nodes which are subkeys of "nodeh".
This is a wrapper around the hivex(3) call of the same name.
$g->hivex_node_delete_child ($nodeh);
Delete "nodeh", recursively if necessary.
This is a wrapper around the hivex(3) call of the same name.
$child = $g->hivex_node_get_child ($nodeh, $name);
Return the child of "nodeh" with the name "name", if it exists. This can return 0
meaning the name was not found.
This is a wrapper around the hivex(3) call of the same name.
$valueh = $g->hivex_node_get_value ($nodeh, $key);
Return the value attached to "nodeh" which has the name "key", if it exists. This can
return 0 meaning the key was not found.
This is a wrapper around the hivex(3) call of the same name.
$name = $g->hivex_node_name ($nodeh);
Return the name of "nodeh".
This is a wrapper around the hivex(3) call of the same name.
$parent = $g->hivex_node_parent ($nodeh);
Return the parent node of "nodeh".
This is a wrapper around the hivex(3) call of the same name.
$g->hivex_node_set_value ($nodeh, $key, $t, $val);
Set or replace a single value under the node "nodeh". The "key" is the name, "t" is
the type, and "val" is the data.
This is a wrapper around the hivex(3) call of the same name.
@valuehs = $g->hivex_node_values ($nodeh);
Return the array of (key, datatype, data) tuples attached to "nodeh".
This is a wrapper around the hivex(3) call of the same name.
$g->hivex_open ($filename [, verbose => $verbose] [, debug => $debug] [, write =>
$write]);
Open the Windows Registry hive file named filename. If there was any previous hivex
handle associated with this guestfs session, then it is closed.
This is a wrapper around the hivex(3) call of the same name.
$nodeh = $g->hivex_root ();
Return the root node of the hive.
This is a wrapper around the hivex(3) call of the same name.
$key = $g->hivex_value_key ($valueh);
Return the key (name) field of a (key, datatype, data) tuple.
This is a wrapper around the hivex(3) call of the same name.
$datatype = $g->hivex_value_type ($valueh);
Return the data type field from a (key, datatype, data) tuple.
This is a wrapper around the hivex(3) call of the same name.
$databuf = $g->hivex_value_utf8 ($valueh);
This calls "$g->hivex_value_value" (which returns the data field from a hivex value
tuple). It then assumes that the field is a UTF-16LE string and converts the result
to UTF-8 (or if this is not possible, it returns an error).
This is useful for reading strings out of the Windows registry. However it is not
foolproof because the registry is not strongly-typed and fields can contain arbitrary
or unexpected data.
$databuf = $g->hivex_value_value ($valueh);
Return the data field of a (key, datatype, data) tuple.
This is a wrapper around the hivex(3) call of the same name.
See also: "$g->hivex_value_utf8".
$content = $g->initrd_cat ($initrdpath, $filename);
This command unpacks the file filename from the initrd file called initrdpath. The
filename must be given without the initial / character.
For example, in guestfish you could use the following command to examine the boot
script (usually called /init) contained in a Linux initrd or initramfs image:
initrd-cat /boot/initrd-<version>.img init
See also "$g->initrd_list".
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
@filenames = $g->initrd_list ($path);
This command lists out files contained in an initrd.
The files are listed without any initial / character. The files are listed in the
order they appear (not necessarily alphabetical). Directory names are listed as
separate items.
Old Linux kernels (2.4 and earlier) used a compressed ext2 filesystem as initrd. We
only support the newer initramfs format (compressed cpio files).
$wd = $g->inotify_add_watch ($path, $mask);
Watch "path" for the events listed in "mask".
Note that if "path" is a directory then events within that directory are watched, but
this does not happen recursively (in subdirectories).
Note for non-C or non-Linux callers: the inotify events are defined by the Linux
kernel ABI and are listed in /usr/include/sys/inotify.h.
$g->inotify_close ();
This closes the inotify handle which was previously opened by inotify_init. It
removes all watches, throws away any pending events, and deallocates all resources.
@paths = $g->inotify_files ();
This function is a helpful wrapper around "$g->inotify_read" which just returns a list
of pathnames of objects that were touched. The returned pathnames are sorted and
deduplicated.
$g->inotify_init ($maxevents);
This command creates a new inotify handle. The inotify subsystem can be used to
notify events which happen to objects in the guest filesystem.
"maxevents" is the maximum number of events which will be queued up between calls to
"$g->inotify_read" or "$g->inotify_files". If this is passed as 0, then the kernel
(or previously set) default is used. For Linux 2.6.29 the default was 16384 events.
Beyond this limit, the kernel throws away events, but records the fact that it threw
them away by setting a flag "IN_Q_OVERFLOW" in the returned structure list (see
"$g->inotify_read").
Before any events are generated, you have to add some watches to the internal watch
list. See: "$g->inotify_add_watch" and "$g->inotify_rm_watch".
Queued up events should be read periodically by calling "$g->inotify_read" (or
"$g->inotify_files" which is just a helpful wrapper around "$g->inotify_read"). If
you don't read the events out often enough then you risk the internal queue
overflowing.
The handle should be closed after use by calling "$g->inotify_close". This also
removes any watches automatically.
See also inotify(7) for an overview of the inotify interface as exposed by the Linux
kernel, which is roughly what we expose via libguestfs. Note that there is one global
inotify handle per libguestfs instance.
@events = $g->inotify_read ();
Return the complete queue of events that have happened since the previous read call.
If no events have happened, this returns an empty list.
Note: In order to make sure that all events have been read, you must call this
function repeatedly until it returns an empty list. The reason is that the call will
read events up to the maximum appliance-to-host message size and leave remaining
events in the queue.
$g->inotify_rm_watch ($wd);
Remove a previously defined inotify watch. See "$g->inotify_add_watch".
$arch = $g->inspect_get_arch ($root);
This returns the architecture of the inspected operating system. The possible return
values are listed under "$g->file_architecture".
If the architecture could not be determined, then the string "unknown" is returned.
Please read "INSPECTION" in guestfs(3) for more details.
$distro = $g->inspect_get_distro ($root);
This returns the distro (distribution) of the inspected operating system.
Currently defined distros are:
"alpinelinux"
Alpine Linux.
"altlinux"
ALT Linux.
"archlinux"
Arch Linux.
"buildroot"
Buildroot-derived distro, but not one we specifically recognize.
"centos"
CentOS.
"cirros"
Cirros.
"coreos"
CoreOS.
"debian"
Debian.
"fedora"
Fedora.
"freebsd"
FreeBSD.
"freedos"
FreeDOS.
"frugalware"
Frugalware.
"gentoo"
Gentoo.
"linuxmint"
Linux Mint.
"mageia"
Mageia.
"mandriva"
Mandriva.
"meego"
MeeGo.
"netbsd"
NetBSD.
"openbsd"
OpenBSD.
"opensuse"
OpenSUSE.
"oraclelinux"
Oracle Linux.
"pardus"
Pardus.
"pldlinux"
PLD Linux.
"redhat-based"
Some Red Hat-derived distro.
"rhel"
Red Hat Enterprise Linux.
"scientificlinux"
Scientific Linux.
"slackware"
Slackware.
"sles"
SuSE Linux Enterprise Server or Desktop.
"suse-based"
Some openSuSE-derived distro.
"ttylinux"
ttylinux.
"ubuntu"
Ubuntu.
"unknown"
The distro could not be determined.
"windows"
Windows does not have distributions. This string is returned if the OS type is
Windows.
Future versions of libguestfs may return other strings here. The caller should be
prepared to handle any string.
Please read "INSPECTION" in guestfs(3) for more details.
%drives = $g->inspect_get_drive_mappings ($root);
This call is useful for Windows which uses a primitive system of assigning drive
letters (like C:\) to partitions. This inspection API examines the Windows Registry
to find out how disks/partitions are mapped to drive letters, and returns a hash table
as in the example below:
C => /dev/vda2
E => /dev/vdb1
F => /dev/vdc1
Note that keys are drive letters. For Windows, the key is case insensitive and just
contains the drive letter, without the customary colon separator character.
In future we may support other operating systems that also used drive letters, but the
keys for those might not be case insensitive and might be longer than 1 character.
For example in OS-9, hard drives were named "h0", "h1" etc.
For Windows guests, currently only hard drive mappings are returned. Removable disks
(eg. DVD-ROMs) are ignored.
For guests that do not use drive mappings, or if the drive mappings could not be
determined, this returns an empty hash table.
Please read "INSPECTION" in guestfs(3) for more details. See also
"$g->inspect_get_mountpoints", "$g->inspect_get_filesystems".
@filesystems = $g->inspect_get_filesystems ($root);
This returns a list of all the filesystems that we think are associated with this
operating system. This includes the root filesystem, other ordinary filesystems, and
non-mounted devices like swap partitions.
In the case of a multi-boot virtual machine, it is possible for a filesystem to be
shared between operating systems.
Please read "INSPECTION" in guestfs(3) for more details. See also
"$g->inspect_get_mountpoints".
$format = $g->inspect_get_format ($root);
This returns the format of the inspected operating system. You can use it to detect
install images, live CDs and similar.
Currently defined formats are:
"installed"
This is an installed operating system.
"installer"
The disk image being inspected is not an installed operating system, but a
bootable install disk, live CD, or similar.
"unknown"
The format of this disk image is not known.
Future versions of libguestfs may return other strings here. The caller should be
prepared to handle any string.
Please read "INSPECTION" in guestfs(3) for more details.
$hostname = $g->inspect_get_hostname ($root);
This function returns the hostname of the operating system as found by inspection of
the guest's configuration files.
If the hostname could not be determined, then the string "unknown" is returned.
Please read "INSPECTION" in guestfs(3) for more details.
$icon = $g->inspect_get_icon ($root [, favicon => $favicon] [, highquality =>
$highquality]);
This function returns an icon corresponding to the inspected operating system. The
icon is returned as a buffer containing a PNG image (re-encoded to PNG if necessary).
If it was not possible to get an icon this function returns a zero-length (non-NULL)
buffer. Callers must check for this case.
Libguestfs will start by looking for a file called /etc/favicon.png or
C:\etc\favicon.png and if it has the correct format, the contents of this file will be
returned. You can disable favicons by passing the optional "favicon" boolean as false
(default is true).
If finding the favicon fails, then we look in other places in the guest for a suitable
icon.
If the optional "highquality" boolean is true then only high quality icons are
returned, which means only icons of high resolution with an alpha channel. The
default (false) is to return any icon we can, even if it is of substandard quality.
Notes:
• Unlike most other inspection API calls, the guest's disks must be mounted up
before you call this, since it needs to read information from the guest filesystem
during the call.
• Security: The icon data comes from the untrusted guest, and should be treated with
caution. PNG files have been known to contain exploits. Ensure that libpng (or
other relevant libraries) are fully up to date before trying to process or display
the icon.
• The PNG image returned can be any size. It might not be square. Libguestfs tries
to return the largest, highest quality icon available. The application must scale
the icon to the required size.
• Extracting icons from Windows guests requires the external "wrestool" program from
the "icoutils" package, and several programs ("bmptopnm", "pnmtopng", "pamcut")
from the "netpbm" package. These must be installed separately.
• Operating system icons are usually trademarks. Seek legal advice before using
trademarks in applications.
$major = $g->inspect_get_major_version ($root);
This returns the major version number of the inspected operating system.
Windows uses a consistent versioning scheme which is not reflected in the popular
public names used by the operating system. Notably the operating system known as
"Windows 7" is really version 6.1 (ie. major = 6, minor = 1). You can find out the
real versions corresponding to releases of Windows by consulting Wikipedia or MSDN.
If the version could not be determined, then 0 is returned.
Please read "INSPECTION" in guestfs(3) for more details.
$minor = $g->inspect_get_minor_version ($root);
This returns the minor version number of the inspected operating system.
If the version could not be determined, then 0 is returned.
Please read "INSPECTION" in guestfs(3) for more details. See also
"$g->inspect_get_major_version".
%mountpoints = $g->inspect_get_mountpoints ($root);
This returns a hash of where we think the filesystems associated with this operating
system should be mounted. Callers should note that this is at best an educated guess
made by reading configuration files such as /etc/fstab. In particular note that this
may return filesystems which are non-existent or not mountable and callers should be
prepared to handle or ignore failures if they try to mount them.
Each element in the returned hashtable has a key which is the path of the mountpoint
(eg. /boot) and a value which is the filesystem that would be mounted there (eg.
/dev/sda1).
Non-mounted devices such as swap devices are not returned in this list.
For operating systems like Windows which still use drive letters, this call will only
return an entry for the first drive "mounted on" /. For information about the mapping
of drive letters to partitions, see "$g->inspect_get_drive_mappings".
Please read "INSPECTION" in guestfs(3) for more details. See also
"$g->inspect_get_filesystems".
$packageformat = $g->inspect_get_package_format ($root);
This function and "$g->inspect_get_package_management" return the package format and
package management tool used by the inspected operating system. For example for
Fedora these functions would return "rpm" (package format), and "yum" or "dnf"
(package management).
This returns the string "unknown" if we could not determine the package format or if
the operating system does not have a real packaging system (eg. Windows).
Possible strings include: "rpm", "deb", "ebuild", "pisi", "pacman", "pkgsrc", "apk".
Future versions of libguestfs may return other strings.
Please read "INSPECTION" in guestfs(3) for more details.
$packagemanagement = $g->inspect_get_package_management ($root);
"$g->inspect_get_package_format" and this function return the package format and
package management tool used by the inspected operating system. For example for
Fedora these functions would return "rpm" (package format), and "yum" or "dnf"
(package management).
This returns the string "unknown" if we could not determine the package management
tool or if the operating system does not have a real packaging system (eg. Windows).
Possible strings include: "yum", "dnf", "up2date", "apt" (for all Debian derivatives),
"portage", "pisi", "pacman", "urpmi", "zypper", "apk". Future versions of libguestfs
may return other strings.
Please read "INSPECTION" in guestfs(3) for more details.
$product = $g->inspect_get_product_name ($root);
This returns the product name of the inspected operating system. The product name is
generally some freeform string which can be displayed to the user, but should not be
parsed by programs.
If the product name could not be determined, then the string "unknown" is returned.
Please read "INSPECTION" in guestfs(3) for more details.
$variant = $g->inspect_get_product_variant ($root);
This returns the product variant of the inspected operating system.
For Windows guests, this returns the contents of the Registry key
"HKLM\Software\Microsoft\Windows NT\CurrentVersion" "InstallationType" which is
usually a string such as "Client" or "Server" (other values are possible). This can
be used to distinguish consumer and enterprise versions of Windows that have the same
version number (for example, Windows 7 and Windows 2008 Server are both version 6.1,
but the former is "Client" and the latter is "Server").
For enterprise Linux guests, in future we intend this to return the product variant
such as "Desktop", "Server" and so on. But this is not implemented at present.
If the product variant could not be determined, then the string "unknown" is returned.
Please read "INSPECTION" in guestfs(3) for more details. See also
"$g->inspect_get_product_name", "$g->inspect_get_major_version".
@roots = $g->inspect_get_roots ();
This function is a convenient way to get the list of root devices, as returned from a
previous call to "$g->inspect_os", but without redoing the whole inspection process.
This returns an empty list if either no root devices were found or the caller has not
called "$g->inspect_os".
Please read "INSPECTION" in guestfs(3) for more details.
$name = $g->inspect_get_type ($root);
This returns the type of the inspected operating system. Currently defined types are:
"linux"
Any Linux-based operating system.
"windows"
Any Microsoft Windows operating system.
"freebsd"
FreeBSD.
"netbsd"
NetBSD.
"openbsd"
OpenBSD.
"hurd"
GNU/Hurd.
"dos"
MS-DOS, FreeDOS and others.
"minix"
MINIX.
"unknown"
The operating system type could not be determined.
Future versions of libguestfs may return other strings here. The caller should be
prepared to handle any string.
Please read "INSPECTION" in guestfs(3) for more details.
$controlset = $g->inspect_get_windows_current_control_set ($root);
This returns the Windows CurrentControlSet of the inspected guest. The
CurrentControlSet is a registry key name such as "ControlSet001".
This call assumes that the guest is Windows and that the Registry could be examined by
inspection. If this is not the case then an error is returned.
Please read "INSPECTION" in guestfs(3) for more details.
$systemroot = $g->inspect_get_windows_systemroot ($root);
This returns the Windows systemroot of the inspected guest. The systemroot is a
directory path such as /WINDOWS.
This call assumes that the guest is Windows and that the systemroot could be
determined by inspection. If this is not the case then an error is returned.
Please read "INSPECTION" in guestfs(3) for more details.
$live = $g->inspect_is_live ($root);
If "$g->inspect_get_format" returns "installer" (this is an install disk), then this
returns true if a live image was detected on the disk.
Please read "INSPECTION" in guestfs(3) for more details.
$multipart = $g->inspect_is_multipart ($root);
If "$g->inspect_get_format" returns "installer" (this is an install disk), then this
returns true if the disk is part of a set.
Please read "INSPECTION" in guestfs(3) for more details.
$netinst = $g->inspect_is_netinst ($root);
If "$g->inspect_get_format" returns "installer" (this is an install disk), then this
returns true if the disk is a network installer, ie. not a self-contained install CD
but one which is likely to require network access to complete the install.
Please read "INSPECTION" in guestfs(3) for more details.
@applications = $g->inspect_list_applications ($root);
Return the list of applications installed in the operating system.
Note: This call works differently from other parts of the inspection API. You have to
call "$g->inspect_os", then "$g->inspect_get_mountpoints", then mount up the disks,
before calling this. Listing applications is a significantly more difficult operation
which requires access to the full filesystem. Also note that unlike the other
"$g->inspect_get_*" calls which are just returning data cached in the libguestfs
handle, this call actually reads parts of the mounted filesystems during the call.
This returns an empty list if the inspection code was not able to determine the list
of applications.
The application structure contains the following fields:
"app_name"
The name of the application. For Red Hat-derived and Debian-derived Linux guests,
this is the package name.
"app_display_name"
The display name of the application, sometimes localized to the install language
of the guest operating system.
If unavailable this is returned as an empty string "". Callers needing to display
something can use "app_name" instead.
"app_epoch"
For package managers which use epochs, this contains the epoch of the package (an
integer). If unavailable, this is returned as 0.
"app_version"
The version string of the application or package. If unavailable this is returned
as an empty string "".
"app_release"
The release string of the application or package, for package managers that use
this. If unavailable this is returned as an empty string "".
"app_install_path"
The installation path of the application (on operating systems such as Windows
which use installation paths). This path is in the format used by the guest
operating system, it is not a libguestfs path.
If unavailable this is returned as an empty string "".
"app_trans_path"
The install path translated into a libguestfs path. If unavailable this is
returned as an empty string "".
"app_publisher"
The name of the publisher of the application, for package managers that use this.
If unavailable this is returned as an empty string "".
"app_url"
The URL (eg. upstream URL) of the application. If unavailable this is returned as
an empty string "".
"app_source_package"
For packaging systems which support this, the name of the source package. If
unavailable this is returned as an empty string "".
"app_summary"
A short (usually one line) description of the application or package. If
unavailable this is returned as an empty string "".
"app_description"
A longer description of the application or package. If unavailable this is
returned as an empty string "".
Please read "INSPECTION" in guestfs(3) for more details.
This function is deprecated. In new code, use the "inspect_list_applications2" call
instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@applications2 = $g->inspect_list_applications2 ($root);
Return the list of applications installed in the operating system.
Note: This call works differently from other parts of the inspection API. You have to
call "$g->inspect_os", then "$g->inspect_get_mountpoints", then mount up the disks,
before calling this. Listing applications is a significantly more difficult operation
which requires access to the full filesystem. Also note that unlike the other
"$g->inspect_get_*" calls which are just returning data cached in the libguestfs
handle, this call actually reads parts of the mounted filesystems during the call.
This returns an empty list if the inspection code was not able to determine the list
of applications.
The application structure contains the following fields:
"app2_name"
The name of the application. For Red Hat-derived and Debian-derived Linux guests,
this is the package name.
"app2_display_name"
The display name of the application, sometimes localized to the install language
of the guest operating system.
If unavailable this is returned as an empty string "". Callers needing to display
something can use "app2_name" instead.
"app2_epoch"
For package managers which use epochs, this contains the epoch of the package (an
integer). If unavailable, this is returned as 0.
"app2_version"
The version string of the application or package. If unavailable this is returned
as an empty string "".
"app2_release"
The release string of the application or package, for package managers that use
this. If unavailable this is returned as an empty string "".
"app2_arch"
The architecture string of the application or package, for package managers that
use this. If unavailable this is returned as an empty string "".
"app2_install_path"
The installation path of the application (on operating systems such as Windows
which use installation paths). This path is in the format used by the guest
operating system, it is not a libguestfs path.
If unavailable this is returned as an empty string "".
"app2_trans_path"
The install path translated into a libguestfs path. If unavailable this is
returned as an empty string "".
"app2_publisher"
The name of the publisher of the application, for package managers that use this.
If unavailable this is returned as an empty string "".
"app2_url"
The URL (eg. upstream URL) of the application. If unavailable this is returned as
an empty string "".
"app2_source_package"
For packaging systems which support this, the name of the source package. If
unavailable this is returned as an empty string "".
"app2_summary"
A short (usually one line) description of the application or package. If
unavailable this is returned as an empty string "".
"app2_description"
A longer description of the application or package. If unavailable this is
returned as an empty string "".
Please read "INSPECTION" in guestfs(3) for more details.
@roots = $g->inspect_os ();
This function uses other libguestfs functions and certain heuristics to inspect the
disk(s) (usually disks belonging to a virtual machine), looking for operating systems.
The list returned is empty if no operating systems were found.
If one operating system was found, then this returns a list with a single element,
which is the name of the root filesystem of this operating system. It is also
possible for this function to return a list containing more than one element,
indicating a dual-boot or multi-boot virtual machine, with each element being the root
filesystem of one of the operating systems.
You can pass the root string(s) returned to other "$g->inspect_get_*" functions in
order to query further information about each operating system, such as the name and
version.
This function uses other libguestfs features such as "$g->mount_ro" and
"$g->umount_all" in order to mount and unmount filesystems and look at the contents.
This should be called with no disks currently mounted. The function may also use
Augeas, so any existing Augeas handle will be closed.
This function cannot decrypt encrypted disks. The caller must do that first
(supplying the necessary keys) if the disk is encrypted.
Please read "INSPECTION" in guestfs(3) for more details.
See also "$g->list_filesystems".
$flag = $g->is_blockdev ($path [, followsymlinks => $followsymlinks]);
This returns "true" if and only if there is a block device with the given "path" name.
If the optional flag "followsymlinks" is true, then a symlink (or chain of symlinks)
that ends with a block device also causes the function to return true.
This call only looks at files within the guest filesystem. Libguestfs partitions and
block devices (eg. /dev/sda) cannot be used as the "path" parameter of this call.
See also "$g->stat".
$flag = $g->is_blockdev_opts ($path [, followsymlinks => $followsymlinks]);
This is an alias of "is_blockdev".
$busy = $g->is_busy ();
This always returns false. This function is deprecated with no replacement. Do not
use this function.
For more information on states, see guestfs(3).
$flag = $g->is_chardev ($path [, followsymlinks => $followsymlinks]);
This returns "true" if and only if there is a character device with the given "path"
name.
If the optional flag "followsymlinks" is true, then a symlink (or chain of symlinks)
that ends with a chardev also causes the function to return true.
See also "$g->stat".
$flag = $g->is_chardev_opts ($path [, followsymlinks => $followsymlinks]);
This is an alias of "is_chardev".
$config = $g->is_config ();
This returns true iff this handle is being configured (in the "CONFIG" state).
For more information on states, see guestfs(3).
$dirflag = $g->is_dir ($path [, followsymlinks => $followsymlinks]);
This returns "true" if and only if there is a directory with the given "path" name.
Note that it returns false for other objects like files.
If the optional flag "followsymlinks" is true, then a symlink (or chain of symlinks)
that ends with a directory also causes the function to return true.
See also "$g->stat".
$dirflag = $g->is_dir_opts ($path [, followsymlinks => $followsymlinks]);
This is an alias of "is_dir".
$flag = $g->is_fifo ($path [, followsymlinks => $followsymlinks]);
This returns "true" if and only if there is a FIFO (named pipe) with the given "path"
name.
If the optional flag "followsymlinks" is true, then a symlink (or chain of symlinks)
that ends with a FIFO also causes the function to return true.
See also "$g->stat".
$flag = $g->is_fifo_opts ($path [, followsymlinks => $followsymlinks]);
This is an alias of "is_fifo".
$fileflag = $g->is_file ($path [, followsymlinks => $followsymlinks]);
This returns "true" if and only if there is a regular file with the given "path" name.
Note that it returns false for other objects like directories.
If the optional flag "followsymlinks" is true, then a symlink (or chain of symlinks)
that ends with a file also causes the function to return true.
See also "$g->stat".
$fileflag = $g->is_file_opts ($path [, followsymlinks => $followsymlinks]);
This is an alias of "is_file".
$launching = $g->is_launching ();
This returns true iff this handle is launching the subprocess (in the "LAUNCHING"
state).
For more information on states, see guestfs(3).
$lvflag = $g->is_lv ($device);
This command tests whether "device" is a logical volume, and returns true iff this is
the case.
$ready = $g->is_ready ();
This returns true iff this handle is ready to accept commands (in the "READY" state).
For more information on states, see guestfs(3).
$flag = $g->is_socket ($path [, followsymlinks => $followsymlinks]);
This returns "true" if and only if there is a Unix domain socket with the given "path"
name.
If the optional flag "followsymlinks" is true, then a symlink (or chain of symlinks)
that ends with a socket also causes the function to return true.
See also "$g->stat".
$flag = $g->is_socket_opts ($path [, followsymlinks => $followsymlinks]);
This is an alias of "is_socket".
$flag = $g->is_symlink ($path);
This returns "true" if and only if there is a symbolic link with the given "path"
name.
See also "$g->stat".
$flag = $g->is_whole_device ($device);
This returns "true" if and only if "device" refers to a whole block device. That is,
not a partition or a logical device.
$zeroflag = $g->is_zero ($path);
This returns true iff the file exists and the file is empty or it contains all zero
bytes.
$zeroflag = $g->is_zero_device ($device);
This returns true iff the device exists and contains all zero bytes.
Note that for large devices this can take a long time to run.
%isodata = $g->isoinfo ($isofile);
This is the same as "$g->isoinfo_device" except that it works for an ISO file located
inside some other mounted filesystem. Note that in the common case where you have
added an ISO file as a libguestfs device, you would not call this. Instead you would
call "$g->isoinfo_device".
%isodata = $g->isoinfo_device ($device);
"device" is an ISO device. This returns a struct of information read from the primary
volume descriptor (the ISO equivalent of the superblock) of the device.
Usually it is more efficient to use the isoinfo(1) command with the -d option on the
host to analyze ISO files, instead of going through libguestfs.
For information on the primary volume descriptor fields, see
<http://wiki.osdev.org/ISO_9660#The_Primary_Volume_Descriptor>
$g->journal_close ();
Close the journal handle.
@fields = $g->journal_get ();
Read the current journal entry. This returns all the fields in the journal as a set
of "(attrname, attrval)" pairs. The "attrname" is the field name (a string).
The "attrval" is the field value (a binary blob, often but not always a string).
Please note that "attrval" is a byte array, not a \0-terminated C string.
The length of data may be truncated to the data threshold (see:
"$g->journal_set_data_threshold", "$g->journal_get_data_threshold").
If you set the data threshold to unlimited (0) then this call can read a journal entry
of any size, ie. it is not limited by the libguestfs protocol.
$threshold = $g->journal_get_data_threshold ();
Get the current data threshold for reading journal entries. This is a hint to the
journal that it may truncate data fields to this size when reading them (note also
that it may not truncate them). If this returns 0, then the threshold is unlimited.
See also "$g->journal_set_data_threshold".
$usec = $g->journal_get_realtime_usec ();
Get the realtime (wallclock) timestamp of the current journal entry.
$more = $g->journal_next ();
Move to the next journal entry. You have to call this at least once after opening the
handle before you are able to read data.
The returned boolean tells you if there are any more journal records to read. "true"
means you can read the next record (eg. using "$g->journal_get"), and "false" means
you have reached the end of the journal.
$g->journal_open ($directory);
Open the systemd journal located in directory. Any previously opened journal handle
is closed.
The contents of the journal can be read using "$g->journal_next" and
"$g->journal_get".
After you have finished using the journal, you should close the handle by calling
"$g->journal_close".
$g->journal_set_data_threshold ($threshold);
Set the data threshold for reading journal entries. This is a hint to the journal
that it may truncate data fields to this size when reading them (note also that it may
not truncate them). If you set this to 0, then the threshold is unlimited.
See also "$g->journal_get_data_threshold".
$rskip = $g->journal_skip ($skip);
Skip forwards ("skip X 0") or backwards ("skip < 0") in the journal.
The number of entries actually skipped is returned (note "rskip X 0"). If this is not
the same as the absolute value of the skip parameter ("|skip|") you passed in then it
means you have reached the end or the start of the journal.
$g->kill_subprocess ();
This kills the hypervisor.
Do not call this. See: "$g->shutdown" instead.
This function is deprecated. In new code, use the "shutdown" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->launch ();
You should call this after configuring the handle (eg. adding drives) but before
performing any actions.
Do not call "$g->launch" twice on the same handle. Although it will not give an error
(for historical reasons), the precise behaviour when you do this is not well defined.
Handles are very cheap to create, so create a new one for each launch.
$g->lchown ($owner, $group, $path);
Change the file owner to "owner" and group to "group". This is like "$g->chown" but
if "path" is a symlink then the link itself is changed, not the target.
Only numeric uid and gid are supported. If you want to use names, you will need to
locate and parse the password file yourself (Augeas support makes this relatively
easy).
$g->ldmtool_create_all ();
This function scans all block devices looking for Windows dynamic disk volumes and
partitions, and creates devices for any that were found.
Call "$g->list_ldm_volumes" and "$g->list_ldm_partitions" to return all devices.
Note that you don't normally need to call this explicitly, since it is done
automatically at "$g->launch" time. However you might want to call this function if
you have hotplugged disks or have just created a Windows dynamic disk.
@disks = $g->ldmtool_diskgroup_disks ($diskgroup);
Return the disks in a Windows dynamic disk group. The "diskgroup" parameter should be
the GUID of a disk group, one element from the list returned by "$g->ldmtool_scan".
$name = $g->ldmtool_diskgroup_name ($diskgroup);
Return the name of a Windows dynamic disk group. The "diskgroup" parameter should be
the GUID of a disk group, one element from the list returned by "$g->ldmtool_scan".
@volumes = $g->ldmtool_diskgroup_volumes ($diskgroup);
Return the volumes in a Windows dynamic disk group. The "diskgroup" parameter should
be the GUID of a disk group, one element from the list returned by "$g->ldmtool_scan".
$g->ldmtool_remove_all ();
This is essentially the opposite of "$g->ldmtool_create_all". It removes the device
mapper mappings for all Windows dynamic disk volumes
@guids = $g->ldmtool_scan ();
This function scans for Windows dynamic disks. It returns a list of identifiers
(GUIDs) for all disk groups that were found. These identifiers can be passed to other
"$g->ldmtool_*" functions.
This function scans all block devices. To scan a subset of block devices, call
"$g->ldmtool_scan_devices" instead.
@guids = $g->ldmtool_scan_devices (\@devices);
This function scans for Windows dynamic disks. It returns a list of identifiers
(GUIDs) for all disk groups that were found. These identifiers can be passed to other
"$g->ldmtool_*" functions.
The parameter "devices" is a list of block devices which are scanned. If this list is
empty, all block devices are scanned.
$hint = $g->ldmtool_volume_hint ($diskgroup, $volume);
Return the hint field of the volume named "volume" in the disk group with GUID
"diskgroup". This may not be defined, in which case the empty string is returned.
The hint field is often, though not always, the name of a Windows drive, eg. "E:".
@partitions = $g->ldmtool_volume_partitions ($diskgroup, $volume);
Return the list of partitions in the volume named "volume" in the disk group with GUID
"diskgroup".
$voltype = $g->ldmtool_volume_type ($diskgroup, $volume);
Return the type of the volume named "volume" in the disk group with GUID "diskgroup".
Possible volume types that can be returned here include: "simple", "spanned",
"striped", "mirrored", "raid5". Other types may also be returned.
$xattr = $g->lgetxattr ($path, $name);
Get a single extended attribute from file "path" named "name". If "path" is a
symlink, then this call returns an extended attribute from the symlink.
Normally it is better to get all extended attributes from a file in one go by calling
"$g->getxattrs". However some Linux filesystem implementations are buggy and do not
provide a way to list out attributes. For these filesystems (notably ntfs-3g) you
have to know the names of the extended attributes you want in advance and call this
function.
Extended attribute values are blobs of binary data. If there is no extended attribute
named "name", this returns an error.
See also: "$g->lgetxattrs", "$g->getxattr", attr(5).
@xattrs = $g->lgetxattrs ($path);
This is the same as "$g->getxattrs", but if "path" is a symbolic link, then it returns
the extended attributes of the link itself.
@mounttags = $g->list_9p ();
List all 9p filesystems attached to the guest. A list of mount tags is returned.
@devices = $g->list_devices ();
List all the block devices.
The full block device names are returned, eg. /dev/sda.
See also "$g->list_filesystems".
%labels = $g->list_disk_labels ();
If you add drives using the optional "label" parameter of "$g->add_drive_opts", you
can use this call to map between disk labels, and raw block device and partition names
(like /dev/sda and /dev/sda1).
This returns a hashtable, where keys are the disk labels (without the
/dev/disk/guestfs prefix), and the values are the full raw block device and partition
names (eg. /dev/sda and /dev/sda1).
@devices = $g->list_dm_devices ();
List all device mapper devices.
The returned list contains /dev/mapper/* devices, eg. ones created by a previous call
to "$g->luks_open".
Device mapper devices which correspond to logical volumes are not returned in this
list. Call "$g->lvs" if you want to list logical volumes.
%fses = $g->list_filesystems ();
This inspection command looks for filesystems on partitions, block devices and logical
volumes, returning a list of "mountables" containing filesystems and their type.
The return value is a hash, where the keys are the devices containing filesystems, and
the values are the filesystem types. For example:
"/dev/sda1" => "ntfs"
"/dev/sda2" => "ext2"
"/dev/vg_guest/lv_root" => "ext4"
"/dev/vg_guest/lv_swap" => "swap"
The key is not necessarily a block device. It may also be an opaque 'mountable' string
which can be passed to "$g->mount".
The value can have the special value "unknown", meaning the content of the device is
undetermined or empty. "swap" means a Linux swap partition.
This command runs other libguestfs commands, which might include "$g->mount" and
"$g->umount", and therefore you should use this soon after launch and only when
nothing is mounted.
Not all of the filesystems returned will be mountable. In particular, swap partitions
are returned in the list. Also this command does not check that each filesystem found
is valid and mountable, and some filesystems might be mountable but require special
options. Filesystems may not all belong to a single logical operating system (use
"$g->inspect_os" to look for OSes).
@devices = $g->list_ldm_partitions ();
This function returns all Windows dynamic disk partitions that were found at launch
time. It returns a list of device names.
@devices = $g->list_ldm_volumes ();
This function returns all Windows dynamic disk volumes that were found at launch time.
It returns a list of device names.
@devices = $g->list_md_devices ();
List all Linux md devices.
@partitions = $g->list_partitions ();
List all the partitions detected on all block devices.
The full partition device names are returned, eg. /dev/sda1
This does not return logical volumes. For that you will need to call "$g->lvs".
See also "$g->list_filesystems".
$listing = $g->ll ($directory);
List the files in directory (relative to the root directory, there is no cwd) in the
format of 'ls -la'.
This command is mostly useful for interactive sessions. It is not intended that you
try to parse the output string.
$listing = $g->llz ($directory);
List the files in directory in the format of 'ls -laZ'.
This command is mostly useful for interactive sessions. It is not intended that you
try to parse the output string.
$g->ln ($target, $linkname);
This command creates a hard link using the "ln" command.
$g->ln_f ($target, $linkname);
This command creates a hard link using the "ln -f" command. The -f option removes the
link ("linkname") if it exists already.
$g->ln_s ($target, $linkname);
This command creates a symbolic link using the "ln -s" command.
$g->ln_sf ($target, $linkname);
This command creates a symbolic link using the "ln -sf" command, The -f option removes
the link ("linkname") if it exists already.
$g->lremovexattr ($xattr, $path);
This is the same as "$g->removexattr", but if "path" is a symbolic link, then it
removes an extended attribute of the link itself.
@listing = $g->ls ($directory);
List the files in directory (relative to the root directory, there is no cwd). The
'.' and '..' entries are not returned, but hidden files are shown.
$g->ls0 ($dir, $filenames);
This specialized command is used to get a listing of the filenames in the directory
"dir". The list of filenames is written to the local file filenames (on the host).
In the output file, the filenames are separated by "\0" characters.
"." and ".." are not returned. The filenames are not sorted.
$g->lsetxattr ($xattr, $val, $vallen, $path);
This is the same as "$g->setxattr", but if "path" is a symbolic link, then it sets an
extended attribute of the link itself.
%statbuf = $g->lstat ($path);
Returns file information for the given "path".
This is the same as "$g->stat" except that if "path" is a symbolic link, then the link
is stat-ed, not the file it refers to.
This is the same as the lstat(2) system call.
This function is deprecated. In new code, use the "lstatns" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@statbufs = $g->lstatlist ($path, \@names);
This call allows you to perform the "$g->lstat" operation on multiple files, where all
files are in the directory "path". "names" is the list of files from this directory.
On return you get a list of stat structs, with a one-to-one correspondence to the
"names" list. If any name did not exist or could not be lstat'd, then the "st_ino"
field of that structure is set to "-1".
This call is intended for programs that want to efficiently list a directory contents
without making many round-trips. See also "$g->lxattrlist" for a similarly efficient
call for getting extended attributes.
This function is deprecated. In new code, use the "lstatnslist" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
%statbuf = $g->lstatns ($path);
Returns file information for the given "path".
This is the same as "$g->statns" except that if "path" is a symbolic link, then the
link is stat-ed, not the file it refers to.
This is the same as the lstat(2) system call.
@statbufs = $g->lstatnslist ($path, \@names);
This call allows you to perform the "$g->lstatns" operation on multiple files, where
all files are in the directory "path". "names" is the list of files from this
directory.
On return you get a list of stat structs, with a one-to-one correspondence to the
"names" list. If any name did not exist or could not be lstat'd, then the "st_ino"
field of that structure is set to "-1".
This call is intended for programs that want to efficiently list a directory contents
without making many round-trips. See also "$g->lxattrlist" for a similarly efficient
call for getting extended attributes.
$g->luks_add_key ($device, $key, $newkey, $keyslot);
This command adds a new key on LUKS device "device". "key" is any existing key, and
is used to access the device. "newkey" is the new key to add. "keyslot" is the key
slot that will be replaced.
Note that if "keyslot" already contains a key, then this command will fail. You have
to use "$g->luks_kill_slot" first to remove that key.
$g->luks_close ($device);
This closes a LUKS device that was created earlier by "$g->luks_open" or
"$g->luks_open_ro". The "device" parameter must be the name of the LUKS mapping
device (ie. /dev/mapper/mapname) and not the name of the underlying block device.
$g->luks_format ($device, $key, $keyslot);
This command erases existing data on "device" and formats the device as a LUKS
encrypted device. "key" is the initial key, which is added to key slot "slot". (LUKS
supports 8 key slots, numbered 0-7).
$g->luks_format_cipher ($device, $key, $keyslot, $cipher);
This command is the same as "$g->luks_format" but it also allows you to set the
"cipher" used.
$g->luks_kill_slot ($device, $key, $keyslot);
This command deletes the key in key slot "keyslot" from the encrypted LUKS device
"device". "key" must be one of the other keys.
$g->luks_open ($device, $key, $mapname);
This command opens a block device which has been encrypted according to the Linux
Unified Key Setup (LUKS) standard.
"device" is the encrypted block device or partition.
The caller must supply one of the keys associated with the LUKS block device, in the
"key" parameter.
This creates a new block device called /dev/mapper/mapname. Reads and writes to this
block device are decrypted from and encrypted to the underlying "device" respectively.
If this block device contains LVM volume groups, then calling "$g->vgscan" followed by
"$g->vg_activate_all" will make them visible.
Use "$g->list_dm_devices" to list all device mapper devices.
$g->luks_open_ro ($device, $key, $mapname);
This is the same as "$g->luks_open" except that a read-only mapping is created.
$g->lvcreate ($logvol, $volgroup, $mbytes);
This creates an LVM logical volume called "logvol" on the volume group "volgroup",
with "size" megabytes.
$g->lvcreate_free ($logvol, $volgroup, $percent);
Create an LVM logical volume called /dev/volgroup/logvol, using approximately
"percent" % of the free space remaining in the volume group. Most usefully, when
"percent" is 100 this will create the largest possible LV.
$lv = $g->lvm_canonical_lv_name ($lvname);
This converts alternative naming schemes for LVs that you might find to the canonical
name. For example, /dev/mapper/VG-LV is converted to /dev/VG/LV.
This command returns an error if the "lvname" parameter does not refer to a logical
volume.
See also "$g->is_lv", "$g->canonical_device_name".
$g->lvm_clear_filter ();
This undoes the effect of "$g->lvm_set_filter". LVM will be able to see every block
device.
This command also clears the LVM cache and performs a volume group scan.
$g->lvm_remove_all ();
This command removes all LVM logical volumes, volume groups and physical volumes.
$g->lvm_set_filter (\@devices);
This sets the LVM device filter so that LVM will only be able to "see" the block
devices in the list "devices", and will ignore all other attached block devices.
Where disk image(s) contain duplicate PVs or VGs, this command is useful to get LVM to
ignore the duplicates, otherwise LVM can get confused. Note also there are two types
of duplication possible: either cloned PVs/VGs which have identical UUIDs; or VGs that
are not cloned but just happen to have the same name. In normal operation you cannot
create this situation, but you can do it outside LVM, eg. by cloning disk images or
by bit twiddling inside the LVM metadata.
This command also clears the LVM cache and performs a volume group scan.
You can filter whole block devices or individual partitions.
You cannot use this if any VG is currently in use (eg. contains a mounted
filesystem), even if you are not filtering out that VG.
$g->lvremove ($device);
Remove an LVM logical volume "device", where "device" is the path to the LV, such as
/dev/VG/LV.
You can also remove all LVs in a volume group by specifying the VG name, /dev/VG.
$g->lvrename ($logvol, $newlogvol);
Rename a logical volume "logvol" with the new name "newlogvol".
$g->lvresize ($device, $mbytes);
This resizes (expands or shrinks) an existing LVM logical volume to "mbytes". When
reducing, data in the reduced part is lost.
$g->lvresize_free ($lv, $percent);
This expands an existing logical volume "lv" so that it fills "pc"% of the remaining
free space in the volume group. Commonly you would call this with pc = 100 which
expands the logical volume as much as possible, using all remaining free space in the
volume group.
@logvols = $g->lvs ();
List all the logical volumes detected. This is the equivalent of the lvs(8) command.
This returns a list of the logical volume device names (eg. /dev/VolGroup00/LogVol00).
See also "$g->lvs_full", "$g->list_filesystems".
@logvols = $g->lvs_full ();
List all the logical volumes detected. This is the equivalent of the lvs(8) command.
The "full" version includes all fields.
$uuid = $g->lvuuid ($device);
This command returns the UUID of the LVM LV "device".
@xattrs = $g->lxattrlist ($path, \@names);
This call allows you to get the extended attributes of multiple files, where all files
are in the directory "path". "names" is the list of files from this directory.
On return you get a flat list of xattr structs which must be interpreted sequentially.
The first xattr struct always has a zero-length "attrname". "attrval" in this struct
is zero-length to indicate there was an error doing "lgetxattr" for this file, or is a
C string which is a decimal number (the number of following attributes for this file,
which could be "0"). Then after the first xattr struct are the zero or more
attributes for the first named file. This repeats for the second and subsequent
files.
This call is intended for programs that want to efficiently list a directory contents
without making many round-trips. See also "$g->lstatlist" for a similarly efficient
call for getting standard stats.
$disks = $g->max_disks ();
Return the maximum number of disks that may be added to a handle (eg. by
"$g->add_drive_opts" and similar calls).
This function was added in libguestfs 1.19.7. In previous versions of libguestfs the
limit was 25.
See "MAXIMUM NUMBER OF DISKS" in guestfs(3) for additional information on this topic.
$g->md_create ($name, \@devices [, missingbitmap => $missingbitmap] [, nrdevices =>
$nrdevices] [, spare => $spare] [, chunk => $chunk] [, level => $level]);
Create a Linux md (RAID) device named "name" on the devices in the list "devices".
The optional parameters are:
"missingbitmap"
A bitmap of missing devices. If a bit is set it means that a missing device is
added to the array. The least significant bit corresponds to the first device in
the array.
As examples:
If "devices = ["/dev/sda"]" and "missingbitmap = 0x1" then the resulting array
would be "[<missing>, "/dev/sda"]".
If "devices = ["/dev/sda"]" and "missingbitmap = 0x2" then the resulting array
would be "["/dev/sda", <missing>]".
This defaults to 0 (no missing devices).
The length of "devices" + the number of bits set in "missingbitmap" must equal
"nrdevices" + "spare".
"nrdevices"
The number of active RAID devices.
If not set, this defaults to the length of "devices" plus the number of bits set
in "missingbitmap".
"spare"
The number of spare devices.
If not set, this defaults to 0.
"chunk"
The chunk size in bytes.
"level"
The RAID level, which can be one of: linear, raid0, 0, stripe, raid1, 1, mirror,
raid4, 4, raid5, 5, raid6, 6, raid10, 10. Some of these are synonymous, and more
levels may be added in future.
If not set, this defaults to "raid1".
%info = $g->md_detail ($md);
This command exposes the output of 'mdadm -DY <md>'. The following fields are usually
present in the returned hash. Other fields may also be present.
"level"
The raid level of the MD device.
"devices"
The number of underlying devices in the MD device.
"metadata"
The metadata version used.
"uuid"
The UUID of the MD device.
"name"
The name of the MD device.
@devices = $g->md_stat ($md);
This call returns a list of the underlying devices which make up the single software
RAID array device "md".
To get a list of software RAID devices, call "$g->list_md_devices".
Each structure returned corresponds to one device along with additional status
information:
"mdstat_device"
The name of the underlying device.
"mdstat_index"
The index of this device within the array.
"mdstat_flags"
Flags associated with this device. This is a string containing (in no specific
order) zero or more of the following flags:
"W" write-mostly
"F" device is faulty
"S" device is a RAID spare
"R" replacement
$g->md_stop ($md);
This command deactivates the MD array named "md". The device is stopped, but it is
not destroyed or zeroed.
$g->mkdir ($path);
Create a directory named "path".
$g->mkdir_mode ($path, $mode);
This command creates a directory, setting the initial permissions of the directory to
"mode".
For common Linux filesystems, the actual mode which is set will be "mode & ~umask &
01777". Non-native-Linux filesystems may interpret the mode in other ways.
See also "$g->mkdir", "$g->umask"
$g->mkdir_p ($path);
Create a directory named "path", creating any parent directories as necessary. This
is like the "mkdir -p" shell command.
$dir = $g->mkdtemp ($tmpl);
This command creates a temporary directory. The "tmpl" parameter should be a full
pathname for the temporary directory name with the final six characters being
"XXXXXX".
For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX", the second one being
suitable for Windows filesystems.
The name of the temporary directory that was created is returned.
The temporary directory is created with mode 0700 and is owned by root.
The caller is responsible for deleting the temporary directory and its contents after
use.
See also: mkdtemp(3)
$g->mke2fs ($device [, blockscount => $blockscount] [, blocksize => $blocksize] [,
fragsize => $fragsize] [, blockspergroup => $blockspergroup] [, numberofgroups =>
$numberofgroups] [, bytesperinode => $bytesperinode] [, inodesize => $inodesize] [,
journalsize => $journalsize] [, numberofinodes => $numberofinodes] [, stridesize =>
$stridesize] [, stripewidth => $stripewidth] [, maxonlineresize => $maxonlineresize] [,
reservedblockspercentage => $reservedblockspercentage] [, mmpupdateinterval =>
$mmpupdateinterval] [, journaldevice => $journaldevice] [, label => $label] [,
lastmounteddir => $lastmounteddir] [, creatoros => $creatoros] [, fstype => $fstype] [,
usagetype => $usagetype] [, uuid => $uuid] [, forcecreate => $forcecreate] [,
writesbandgrouponly => $writesbandgrouponly] [, lazyitableinit => $lazyitableinit] [,
lazyjournalinit => $lazyjournalinit] [, testfs => $testfs] [, discard => $discard] [,
quotatype => $quotatype] [, extent => $extent] [, filetype => $filetype] [, flexbg =>
$flexbg] [, hasjournal => $hasjournal] [, journaldev => $journaldev] [, largefile =>
$largefile] [, quota => $quota] [, resizeinode => $resizeinode] [, sparsesuper =>
$sparsesuper] [, uninitbg => $uninitbg]);
"mke2fs" is used to create an ext2, ext3, or ext4 filesystem on "device".
The optional "blockscount" is the size of the filesystem in blocks. If omitted it
defaults to the size of "device". Note if the filesystem is too small to contain a
journal, "mke2fs" will silently create an ext2 filesystem instead.
$g->mke2fs_J ($fstype, $blocksize, $device, $journal);
This creates an ext2/3/4 filesystem on "device" with an external journal on "journal".
It is equivalent to the command:
mke2fs -t fstype -b blocksize -J device=<journal> <device>
See also "$g->mke2journal".
This function is deprecated. In new code, use the "mke2fs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mke2fs_JL ($fstype, $blocksize, $device, $label);
This creates an ext2/3/4 filesystem on "device" with an external journal on the
journal labeled "label".
See also "$g->mke2journal_L".
This function is deprecated. In new code, use the "mke2fs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mke2fs_JU ($fstype, $blocksize, $device, $uuid);
This creates an ext2/3/4 filesystem on "device" with an external journal on the
journal with UUID "uuid".
See also "$g->mke2journal_U".
This function is deprecated. In new code, use the "mke2fs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mke2journal ($blocksize, $device);
This creates an ext2 external journal on "device". It is equivalent to the command:
mke2fs -O journal_dev -b blocksize device
This function is deprecated. In new code, use the "mke2fs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mke2journal_L ($blocksize, $label, $device);
This creates an ext2 external journal on "device" with label "label".
This function is deprecated. In new code, use the "mke2fs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mke2journal_U ($blocksize, $uuid, $device);
This creates an ext2 external journal on "device" with UUID "uuid".
This function is deprecated. In new code, use the "mke2fs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mkfifo ($mode, $path);
This call creates a FIFO (named pipe) called "path" with mode "mode". It is just a
convenient wrapper around "$g->mknod".
Unlike with "$g->mknod", "mode" must contain only permissions bits.
The mode actually set is affected by the umask.
$g->mkfs ($fstype, $device [, blocksize => $blocksize] [, features => $features] [, inode
=> $inode] [, sectorsize => $sectorsize] [, label => $label]);
This function creates a filesystem on "device". The filesystem type is "fstype", for
example "ext3".
The optional arguments are:
"blocksize"
The filesystem block size. Supported block sizes depend on the filesystem type,
but typically they are 1024, 2048 or 4096 for Linux ext2/3 filesystems.
For VFAT and NTFS the "blocksize" parameter is treated as the requested cluster
size.
For UFS block sizes, please see mkfs.ufs(8).
"features"
This passes the -O parameter to the external mkfs program.
For certain filesystem types, this allows extra filesystem features to be
selected. See mke2fs(8) and mkfs.ufs(8) for more details.
You cannot use this optional parameter with the "gfs" or "gfs2" filesystem type.
"inode"
This passes the -I parameter to the external mke2fs(8) program which sets the
inode size (only for ext2/3/4 filesystems at present).
"sectorsize"
This passes the -S parameter to external mkfs.ufs(8) program, which sets sector
size for ufs filesystem.
$g->mkfs_opts ($fstype, $device [, blocksize => $blocksize] [, features => $features] [,
inode => $inode] [, sectorsize => $sectorsize] [, label => $label]);
This is an alias of "mkfs".
$g->mkfs_b ($fstype, $blocksize, $device);
This call is similar to "$g->mkfs", but it allows you to control the block size of the
resulting filesystem. Supported block sizes depend on the filesystem type, but
typically they are 1024, 2048 or 4096 only.
For VFAT and NTFS the "blocksize" parameter is treated as the requested cluster size.
This function is deprecated. In new code, use the "mkfs" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mkfs_btrfs (\@devices [, allocstart => $allocstart] [, bytecount => $bytecount] [,
datatype => $datatype] [, leafsize => $leafsize] [, label => $label] [, metadata =>
$metadata] [, nodesize => $nodesize] [, sectorsize => $sectorsize]);
Create a btrfs filesystem, allowing all configurables to be set. For more information
on the optional arguments, see mkfs.btrfs(8).
Since btrfs filesystems can span multiple devices, this takes a non-empty list of
devices.
To create general filesystems, use "$g->mkfs".
$g->mklost_and_found ($mountpoint);
Make the "lost+found" directory, normally in the root directory of an ext2/3/4
filesystem. "mountpoint" is the directory under which we try to create the
"lost+found" directory.
$g->mkmountpoint ($exemptpath);
"$g->mkmountpoint" and "$g->rmmountpoint" are specialized calls that can be used to
create extra mountpoints before mounting the first filesystem.
These calls are only necessary in some very limited circumstances, mainly the case
where you want to mount a mix of unrelated and/or read-only filesystems together.
For example, live CDs often contain a "Russian doll" nest of filesystems, an ISO outer
layer, with a squashfs image inside, with an ext2/3 image inside that. You can unpack
this as follows in guestfish:
add-ro Fedora-11-i686-Live.iso
run
mkmountpoint /cd
mkmountpoint /sqsh
mkmountpoint /ext3fs
mount /dev/sda /cd
mount-loop /cd/LiveOS/squashfs.img /sqsh
mount-loop /sqsh/LiveOS/ext3fs.img /ext3fs
The inner filesystem is now unpacked under the /ext3fs mountpoint.
"$g->mkmountpoint" is not compatible with "$g->umount_all". You may get unexpected
errors if you try to mix these calls. It is safest to manually unmount filesystems
and remove mountpoints after use.
"$g->umount_all" unmounts filesystems by sorting the paths longest first, so for this
to work for manual mountpoints, you must ensure that the innermost mountpoints have
the longest pathnames, as in the example code above.
For more details see <https://bugzilla.redhat.com/show_bug.cgi?id=599503>
Autosync [see "$g->set_autosync", this is set by default on handles] can cause
"$g->umount_all" to be called when the handle is closed which can also trigger these
issues.
$g->mknod ($mode, $devmajor, $devminor, $path);
This call creates block or character special devices, or named pipes (FIFOs).
The "mode" parameter should be the mode, using the standard constants. "devmajor" and
"devminor" are the device major and minor numbers, only used when creating block and
character special devices.
Note that, just like mknod(2), the mode must be bitwise OR'd with S_IFBLK, S_IFCHR,
S_IFIFO or S_IFSOCK (otherwise this call just creates a regular file). These
constants are available in the standard Linux header files, or you can use
"$g->mknod_b", "$g->mknod_c" or "$g->mkfifo" which are wrappers around this command
which bitwise OR in the appropriate constant for you.
The mode actually set is affected by the umask.
$g->mknod_b ($mode, $devmajor, $devminor, $path);
This call creates a block device node called "path" with mode "mode" and device
major/minor "devmajor" and "devminor". It is just a convenient wrapper around
"$g->mknod".
Unlike with "$g->mknod", "mode" must contain only permissions bits.
The mode actually set is affected by the umask.
$g->mknod_c ($mode, $devmajor, $devminor, $path);
This call creates a char device node called "path" with mode "mode" and device
major/minor "devmajor" and "devminor". It is just a convenient wrapper around
"$g->mknod".
Unlike with "$g->mknod", "mode" must contain only permissions bits.
The mode actually set is affected by the umask.
$g->mkswap ($device [, label => $label] [, uuid => $uuid]);
Create a Linux swap partition on "device".
The option arguments "label" and "uuid" allow you to set the label and/or UUID of the
new swap partition.
$g->mkswap_opts ($device [, label => $label] [, uuid => $uuid]);
This is an alias of "mkswap".
$g->mkswap_L ($label, $device);
Create a swap partition on "device" with label "label".
Note that you cannot attach a swap label to a block device (eg. /dev/sda), just to a
partition. This appears to be a limitation of the kernel or swap tools.
This function is deprecated. In new code, use the "mkswap" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mkswap_U ($uuid, $device);
Create a swap partition on "device" with UUID "uuid".
This function is deprecated. In new code, use the "mkswap" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->mkswap_file ($path);
Create a swap file.
This command just writes a swap file signature to an existing file. To create the
file itself, use something like "$g->fallocate".
$path = $g->mktemp ($tmpl [, suffix => $suffix]);
This command creates a temporary file. The "tmpl" parameter should be a full pathname
for the temporary directory name with the final six characters being "XXXXXX".
For example: "/tmp/myprogXXXXXX" or "/Temp/myprogXXXXXX", the second one being
suitable for Windows filesystems.
The name of the temporary file that was created is returned.
The temporary file is created with mode 0600 and is owned by root.
The caller is responsible for deleting the temporary file after use.
If the optional "suffix" parameter is given, then the suffix (eg. ".txt") is appended
to the temporary name.
See also: "$g->mkdtemp".
$g->modprobe ($modulename);
This loads a kernel module in the appliance.
$g->mount ($mountable, $mountpoint);
Mount a guest disk at a position in the filesystem. Block devices are named /dev/sda,
/dev/sdb and so on, as they were added to the guest. If those block devices contain
partitions, they will have the usual names (eg. /dev/sda1). Also LVM /dev/VG/LV-style
names can be used, or 'mountable' strings returned by "$g->list_filesystems" or
"$g->inspect_get_mountpoints".
The rules are the same as for mount(2): A filesystem must first be mounted on /
before others can be mounted. Other filesystems can only be mounted on directories
which already exist.
The mounted filesystem is writable, if we have sufficient permissions on the
underlying device.
Before libguestfs 1.13.16, this call implicitly added the options "sync" and
"noatime". The "sync" option greatly slowed writes and caused many problems for
users. If your program might need to work with older versions of libguestfs, use
"$g->mount_options" instead (using an empty string for the first parameter if you
don't want any options).
$g->mount_9p ($mounttag, $mountpoint [, options => $options]);
Mount the virtio-9p filesystem with the tag "mounttag" on the directory "mountpoint".
If required, "trans=virtio" will be automatically added to the options. Any other
options required can be passed in the optional "options" parameter.
$g->mount_local ($localmountpoint [, readonly => $readonly] [, options => $options] [,
cachetimeout => $cachetimeout] [, debugcalls => $debugcalls]);
This call exports the libguestfs-accessible filesystem to a local mountpoint
(directory) called "localmountpoint". Ordinary reads and writes to files and
directories under "localmountpoint" are redirected through libguestfs.
If the optional "readonly" flag is set to true, then writes to the filesystem return
error "EROFS".
"options" is a comma-separated list of mount options. See guestmount(1) for some
useful options.
"cachetimeout" sets the timeout (in seconds) for cached directory entries. The
default is 60 seconds. See guestmount(1) for further information.
If "debugcalls" is set to true, then additional debugging information is generated for
every FUSE call.
When "$g->mount_local" returns, the filesystem is ready, but is not processing
requests (access to it will block). You have to call "$g->mount_local_run" to run the
main loop.
See "MOUNT LOCAL" in guestfs(3) for full documentation.
$g->mount_local_run ();
Run the main loop which translates kernel calls to libguestfs calls.
This should only be called after "$g->mount_local" returns successfully. The call
will not return until the filesystem is unmounted.
Note you must not make concurrent libguestfs calls on the same handle from another
thread.
You may call this from a different thread than the one which called "$g->mount_local",
subject to the usual rules for threads and libguestfs (see "MULTIPLE HANDLES AND
MULTIPLE THREADS" in guestfs(3)).
See "MOUNT LOCAL" in guestfs(3) for full documentation.
$g->mount_loop ($file, $mountpoint);
This command lets you mount file (a filesystem image in a file) on a mount point. It
is entirely equivalent to the command "mount -o loop file mountpoint".
$g->mount_options ($options, $mountable, $mountpoint);
This is the same as the "$g->mount" command, but it allows you to set the mount
options as for the mount(8) -o flag.
If the "options" parameter is an empty string, then no options are passed (all options
default to whatever the filesystem uses).
$g->mount_ro ($mountable, $mountpoint);
This is the same as the "$g->mount" command, but it mounts the filesystem with the
read-only (-o ro) flag.
$g->mount_vfs ($options, $vfstype, $mountable, $mountpoint);
This is the same as the "$g->mount" command, but it allows you to set both the mount
options and the vfstype as for the mount(8) -o and -t flags.
%mps = $g->mountpoints ();
This call is similar to "$g->mounts". That call returns a list of devices. This one
returns a hash table (map) of device name to directory where the device is mounted.
@devices = $g->mounts ();
This returns the list of currently mounted filesystems. It returns the list of
devices (eg. /dev/sda1, /dev/VG/LV).
Some internal mounts are not shown.
See also: "$g->mountpoints"
$g->mv ($src, $dest);
This moves a file from "src" to "dest" where "dest" is either a destination filename
or destination directory.
See also: "$g->rename".
$nrdisks = $g->nr_devices ();
This returns the number of whole block devices that were added. This is the same as
the number of devices that would be returned if you called "$g->list_devices".
To find out the maximum number of devices that could be added, call "$g->max_disks".
$status = $g->ntfs_3g_probe ($rw, $device);
This command runs the ntfs-3g.probe(8) command which probes an NTFS "device" for
mountability. (Not all NTFS volumes can be mounted read-write, and some cannot be
mounted at all).
"rw" is a boolean flag. Set it to true if you want to test if the volume can be
mounted read-write. Set it to false if you want to test if the volume can be mounted
read-only.
The return value is an integer which 0 if the operation would succeed, or some non-
zero value documented in the ntfs-3g.probe(8) manual page.
$g->ntfsclone_in ($backupfile, $device);
Restore the "backupfile" (from a previous call to "$g->ntfsclone_out") to "device",
overwriting any existing contents of this device.
$g->ntfsclone_out ($device, $backupfile [, metadataonly => $metadataonly] [, rescue =>
$rescue] [, ignorefscheck => $ignorefscheck] [, preservetimestamps => $preservetimestamps]
[, force => $force]);
Stream the NTFS filesystem "device" to the local file "backupfile". The format used
for the backup file is a special format used by the ntfsclone(8) tool.
If the optional "metadataonly" flag is true, then only the metadata is saved, losing
all the user data (this is useful for diagnosing some filesystem problems).
The optional "rescue", "ignorefscheck", "preservetimestamps" and "force" flags have
precise meanings detailed in the ntfsclone(8) man page.
Use "$g->ntfsclone_in" to restore the file back to a libguestfs device.
$g->ntfsfix ($device [, clearbadsectors => $clearbadsectors]);
This command repairs some fundamental NTFS inconsistencies, resets the NTFS journal
file, and schedules an NTFS consistency check for the first boot into Windows.
This is not an equivalent of Windows "chkdsk". It does not scan the filesystem for
inconsistencies.
The optional "clearbadsectors" flag clears the list of bad sectors. This is useful
after cloning a disk with bad sectors to a new disk.
$g->ntfsresize ($device [, size => $size] [, force => $force]);
This command resizes an NTFS filesystem, expanding or shrinking it to the size of the
underlying device.
The optional parameters are:
"size"
The new size (in bytes) of the filesystem. If omitted, the filesystem is resized
to fit the container (eg. partition).
"force"
If this option is true, then force the resize of the filesystem even if the
filesystem is marked as requiring a consistency check.
After the resize operation, the filesystem is always marked as requiring a
consistency check (for safety). You have to boot into Windows to perform this
check and clear this condition. If you don't set the "force" option then it is
not possible to call "$g->ntfsresize" multiple times on a single filesystem
without booting into Windows between each resize.
See also ntfsresize(8).
$g->ntfsresize_opts ($device [, size => $size] [, force => $force]);
This is an alias of "ntfsresize".
$g->ntfsresize_size ($device, $size);
This command is the same as "$g->ntfsresize" except that it allows you to specify the
new size (in bytes) explicitly.
This function is deprecated. In new code, use the "ntfsresize" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->parse_environment ();
Parse the program's environment and set flags in the handle accordingly. For example
if "LIBGUESTFS_DEBUG=1" then the 'verbose' flag is set in the handle.
Most programs do not need to call this. It is done implicitly when you call
"$g->create".
See "ENVIRONMENT VARIABLES" in guestfs(3) for a list of environment variables that can
affect libguestfs handles. See also "guestfs_create_flags" in guestfs(3), and
"$g->parse_environment_list".
$g->parse_environment_list (\@environment);
Parse the list of strings in the argument "environment" and set flags in the handle
accordingly. For example if "LIBGUESTFS_DEBUG=1" is a string in the list, then the
'verbose' flag is set in the handle.
This is the same as "$g->parse_environment" except that it parses an explicit list of
strings instead of the program's environment.
$g->part_add ($device, $prlogex, $startsect, $endsect);
This command adds a partition to "device". If there is no partition table on the
device, call "$g->part_init" first.
The "prlogex" parameter is the type of partition. Normally you should pass "p" or
"primary" here, but MBR partition tables also support "l" (or "logical") and "e" (or
"extended") partition types.
"startsect" and "endsect" are the start and end of the partition in sectors.
"endsect" may be negative, which means it counts backwards from the end of the disk
("-1" is the last sector).
Creating a partition which covers the whole disk is not so easy. Use "$g->part_disk"
to do that.
$g->part_del ($device, $partnum);
This command deletes the partition numbered "partnum" on "device".
Note that in the case of MBR partitioning, deleting an extended partition also deletes
any logical partitions it contains.
$g->part_disk ($device, $parttype);
This command is simply a combination of "$g->part_init" followed by "$g->part_add" to
create a single primary partition covering the whole disk.
"parttype" is the partition table type, usually "mbr" or "gpt", but other possible
values are described in "$g->part_init".
$bootable = $g->part_get_bootable ($device, $partnum);
This command returns true if the partition "partnum" on "device" has the bootable flag
set.
See also "$g->part_set_bootable".
$guid = $g->part_get_gpt_guid ($device, $partnum);
Return the GUID of numbered GPT partition "partnum".
$guid = $g->part_get_gpt_type ($device, $partnum);
Return the type GUID of numbered GPT partition "partnum". For MBR partitions, return
an appropriate GUID corresponding to the MBR type. Behaviour is undefined for other
partition types.
$idbyte = $g->part_get_mbr_id ($device, $partnum);
Returns the MBR type byte (also known as the ID byte) from the numbered partition
"partnum".
Note that only MBR (old DOS-style) partitions have type bytes. You will get undefined
results for other partition table types (see "$g->part_get_parttype").
$partitiontype = $g->part_get_mbr_part_type ($device, $partnum);
This returns the partition type of an MBR partition numbered "partnum" on device
"device".
It returns "primary", "logical", or "extended".
$name = $g->part_get_name ($device, $partnum);
This gets the partition name on partition numbered "partnum" on device "device". Note
that partitions are numbered from 1.
The partition name can only be read on certain types of partition table. This works
on "gpt" but not on "mbr" partitions.
$parttype = $g->part_get_parttype ($device);
This command examines the partition table on "device" and returns the partition table
type (format) being used.
Common return values include: "msdos" (a DOS/Windows style MBR partition table), "gpt"
(a GPT/EFI-style partition table). Other values are possible, although unusual. See
"$g->part_init" for a full list.
$g->part_init ($device, $parttype);
This creates an empty partition table on "device" of one of the partition types listed
below. Usually "parttype" should be either "msdos" or "gpt" (for large disks).
Initially there are no partitions. Following this, you should call "$g->part_add" for
each partition required.
Possible values for "parttype" are:
efi
gpt Intel EFI / GPT partition table.
This is recommended for >= 2 TB partitions that will be accessed from Linux and
Intel-based Mac OS X. It also has limited backwards compatibility with the "mbr"
format.
mbr
msdos
The standard PC "Master Boot Record" (MBR) format used by MS-DOS and Windows.
This partition type will only work for device sizes up to 2 TB. For large disks
we recommend using "gpt".
Other partition table types that may work but are not supported include:
aix AIX disk labels.
amiga
rdb Amiga "Rigid Disk Block" format.
bsd BSD disk labels.
dasd
DASD, used on IBM mainframes.
dvh MIPS/SGI volumes.
mac Old Mac partition format. Modern Macs use "gpt".
pc98
NEC PC-98 format, common in Japan apparently.
sun Sun disk labels.
@partitions = $g->part_list ($device);
This command parses the partition table on "device" and returns the list of partitions
found.
The fields in the returned structure are:
part_num
Partition number, counting from 1.
part_start
Start of the partition in bytes. To get sectors you have to divide by the
device's sector size, see "$g->blockdev_getss".
part_end
End of the partition in bytes.
part_size
Size of the partition in bytes.
$g->part_set_bootable ($device, $partnum, $bootable);
This sets the bootable flag on partition numbered "partnum" on device "device". Note
that partitions are numbered from 1.
The bootable flag is used by some operating systems (notably Windows) to determine
which partition to boot from. It is by no means universally recognized.
$g->part_set_gpt_guid ($device, $partnum, $guid);
Set the GUID of numbered GPT partition "partnum" to "guid". Return an error if the
partition table of "device" isn't GPT, or if "guid" is not a valid GUID.
$g->part_set_gpt_type ($device, $partnum, $guid);
Set the type GUID of numbered GPT partition "partnum" to "guid". Return an error if
the partition table of "device" isn't GPT, or if "guid" is not a valid GUID.
See <http://en.wikipedia.org/wiki/GUID_Partition_Table#Partition_type_GUIDs> for a
useful list of type GUIDs.
$g->part_set_mbr_id ($device, $partnum, $idbyte);
Sets the MBR type byte (also known as the ID byte) of the numbered partition "partnum"
to "idbyte". Note that the type bytes quoted in most documentation are in fact
hexadecimal numbers, but usually documented without any leading "0x" which might be
confusing.
Note that only MBR (old DOS-style) partitions have type bytes. You will get undefined
results for other partition table types (see "$g->part_get_parttype").
$g->part_set_name ($device, $partnum, $name);
This sets the partition name on partition numbered "partnum" on device "device". Note
that partitions are numbered from 1.
The partition name can only be set on certain types of partition table. This works on
"gpt" but not on "mbr" partitions.
$device = $g->part_to_dev ($partition);
This function takes a partition name (eg. "/dev/sdb1") and removes the partition
number, returning the device name (eg. "/dev/sdb").
The named partition must exist, for example as a string returned from
"$g->list_partitions".
See also "$g->part_to_partnum", "$g->device_index".
$partnum = $g->part_to_partnum ($partition);
This function takes a partition name (eg. "/dev/sdb1") and returns the partition
number (eg. 1).
The named partition must exist, for example as a string returned from
"$g->list_partitions".
See also "$g->part_to_dev".
$g->ping_daemon ();
This is a test probe into the guestfs daemon running inside the libguestfs appliance.
Calling this function checks that the daemon responds to the ping message, without
affecting the daemon or attached block device(s) in any other way.
$content = $g->pread ($path, $count, $offset);
This command lets you read part of a file. It reads "count" bytes of the file,
starting at "offset", from file "path".
This may read fewer bytes than requested. For further details see the pread(2) system
call.
See also "$g->pwrite", "$g->pread_device".
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$content = $g->pread_device ($device, $count, $offset);
This command lets you read part of a block device. It reads "count" bytes of
"device", starting at "offset".
This may read fewer bytes than requested. For further details see the pread(2) system
call.
See also "$g->pread".
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$g->pvchange_uuid ($device);
Generate a new random UUID for the physical volume "device".
$g->pvchange_uuid_all ();
Generate new random UUIDs for all physical volumes.
$g->pvcreate ($device);
This creates an LVM physical volume on the named "device", where "device" should
usually be a partition name such as /dev/sda1.
$g->pvremove ($device);
This wipes a physical volume "device" so that LVM will no longer recognise it.
The implementation uses the "pvremove" command which refuses to wipe physical volumes
that contain any volume groups, so you have to remove those first.
$g->pvresize ($device);
This resizes (expands or shrinks) an existing LVM physical volume to match the new
size of the underlying device.
$g->pvresize_size ($device, $size);
This command is the same as "$g->pvresize" except that it allows you to specify the
new size (in bytes) explicitly.
@physvols = $g->pvs ();
List all the physical volumes detected. This is the equivalent of the pvs(8) command.
This returns a list of just the device names that contain PVs (eg. /dev/sda2).
See also "$g->pvs_full".
@physvols = $g->pvs_full ();
List all the physical volumes detected. This is the equivalent of the pvs(8) command.
The "full" version includes all fields.
$uuid = $g->pvuuid ($device);
This command returns the UUID of the LVM PV "device".
$nbytes = $g->pwrite ($path, $content, $offset);
This command writes to part of a file. It writes the data buffer "content" to the
file "path" starting at offset "offset".
This command implements the pwrite(2) system call, and like that system call it may
not write the full data requested. The return value is the number of bytes that were
actually written to the file. This could even be 0, although short writes are
unlikely for regular files in ordinary circumstances.
See also "$g->pread", "$g->pwrite_device".
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$nbytes = $g->pwrite_device ($device, $content, $offset);
This command writes to part of a device. It writes the data buffer "content" to
"device" starting at offset "offset".
This command implements the pwrite(2) system call, and like that system call it may
not write the full data requested (although short writes to disk devices and
partitions are probably impossible with standard Linux kernels).
See also "$g->pwrite".
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$content = $g->read_file ($path);
This calls returns the contents of the file "path" as a buffer.
Unlike "$g->cat", this function can correctly handle files that contain embedded ASCII
NUL characters.
@lines = $g->read_lines ($path);
Return the contents of the file named "path".
The file contents are returned as a list of lines. Trailing "LF" and "CRLF" character
sequences are not returned.
Note that this function cannot correctly handle binary files (specifically, files
containing "\0" character which is treated as end of string). For those you need to
use the "$g->read_file" function and split the buffer into lines yourself.
@entries = $g->readdir ($dir);
This returns the list of directory entries in directory "dir".
All entries in the directory are returned, including "." and "..". The entries are
not sorted, but returned in the same order as the underlying filesystem.
Also this call returns basic file type information about each file. The "ftyp" field
will contain one of the following characters:
'b' Block special
'c' Char special
'd' Directory
'f' FIFO (named pipe)
'l' Symbolic link
'r' Regular file
's' Socket
'u' Unknown file type
'?' The readdir(3) call returned a "d_type" field with an unexpected value
This function is primarily intended for use by programs. To get a simple list of
names, use "$g->ls". To get a printable directory for human consumption, use
"$g->ll".
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$link = $g->readlink ($path);
This command reads the target of a symbolic link.
@links = $g->readlinklist ($path, \@names);
This call allows you to do a "readlink" operation on multiple files, where all files
are in the directory "path". "names" is the list of files from this directory.
On return you get a list of strings, with a one-to-one correspondence to the "names"
list. Each string is the value of the symbolic link.
If the readlink(2) operation fails on any name, then the corresponding result string
is the empty string "". However the whole operation is completed even if there were
readlink(2) errors, and so you can call this function with names where you don't know
if they are symbolic links already (albeit slightly less efficient).
This call is intended for programs that want to efficiently list a directory contents
without making many round-trips.
$rpath = $g->realpath ($path);
Return the canonicalized absolute pathname of "path". The returned path has no ".",
".." or symbolic link path elements.
$g->remount ($mountpoint [, rw => $rw]);
This call allows you to change the "rw" (readonly/read-write) flag on an already
mounted filesystem at "mountpoint", converting a readonly filesystem to be read-write,
or vice-versa.
Note that at the moment you must supply the "optional" "rw" parameter. In future we
may allow other flags to be adjusted.
$g->remove_drive ($label);
This function is conceptually the opposite of "$g->add_drive_opts". It removes the
drive that was previously added with label "label".
Note that in order to remove drives, you have to add them with labels (see the
optional "label" argument to "$g->add_drive_opts"). If you didn't use a label, then
they cannot be removed.
You can call this function before or after launching the handle. If called after
launch, if the backend supports it, we try to hot unplug the drive: see "HOTPLUGGING"
in guestfs(3). The disk must not be in use (eg. mounted) when you do this. We try to
detect if the disk is in use and stop you from doing this.
$g->removexattr ($xattr, $path);
This call removes the extended attribute named "xattr" of the file "path".
See also: "$g->lremovexattr", attr(5).
$g->rename ($oldpath, $newpath);
Rename a file to a new place on the same filesystem. This is the same as the Linux
rename(2) system call. In most cases you are better to use "$g->mv" instead.
$g->resize2fs ($device);
This resizes an ext2, ext3 or ext4 filesystem to match the size of the underlying
device.
See also "RESIZE2FS ERRORS" in guestfs(3).
$g->resize2fs_M ($device);
This command is the same as "$g->resize2fs", but the filesystem is resized to its
minimum size. This works like the -M option to the "resize2fs" command.
To get the resulting size of the filesystem you should call "$g->tune2fs_l" and read
the "Block size" and "Block count" values. These two numbers, multiplied together,
give the resulting size of the minimal filesystem in bytes.
See also "RESIZE2FS ERRORS" in guestfs(3).
$g->resize2fs_size ($device, $size);
This command is the same as "$g->resize2fs" except that it allows you to specify the
new size (in bytes) explicitly.
See also "RESIZE2FS ERRORS" in guestfs(3).
$g->rm ($path);
Remove the single file "path".
$g->rm_f ($path);
Remove the file "path".
If the file doesn't exist, that error is ignored. (Other errors, eg. I/O errors or
bad paths, are not ignored)
This call cannot remove directories. Use "$g->rmdir" to remove an empty directory, or
"$g->rm_rf" to remove directories recursively.
$g->rm_rf ($path);
Remove the file or directory "path", recursively removing the contents if its a
directory. This is like the "rm -rf" shell command.
$g->rmdir ($path);
Remove the single directory "path".
$g->rmmountpoint ($exemptpath);
This calls removes a mountpoint that was previously created with "$g->mkmountpoint".
See "$g->mkmountpoint" for full details.
$g->rsync ($src, $dest [, archive => $archive] [, deletedest => $deletedest]);
This call may be used to copy or synchronize two directories under the same libguestfs
handle. This uses the rsync(1) program which uses a fast algorithm that avoids
copying files unnecessarily.
"src" and "dest" are the source and destination directories. Files are copied from
"src" to "dest".
The optional arguments are:
"archive"
Turns on archive mode. This is the same as passing the --archive flag to "rsync".
"deletedest"
Delete files at the destination that do not exist at the source.
$g->rsync_in ($remote, $dest [, archive => $archive] [, deletedest => $deletedest]);
This call may be used to copy or synchronize the filesystem on the host or on a remote
computer with the filesystem within libguestfs. This uses the rsync(1) program which
uses a fast algorithm that avoids copying files unnecessarily.
This call only works if the network is enabled. See "$g->set_network" or the
--network option to various tools like guestfish(1).
Files are copied from the remote server and directory specified by "remote" to the
destination directory "dest".
The format of the remote server string is defined by rsync(1). Note that there is no
way to supply a password or passphrase so the target must be set up not to require
one.
The optional arguments are the same as those of "$g->rsync".
$g->rsync_out ($src, $remote [, archive => $archive] [, deletedest => $deletedest]);
This call may be used to copy or synchronize the filesystem within libguestfs with a
filesystem on the host or on a remote computer. This uses the rsync(1) program which
uses a fast algorithm that avoids copying files unnecessarily.
This call only works if the network is enabled. See "$g->set_network" or the
--network option to various tools like guestfish(1).
Files are copied from the source directory "src" to the remote server and directory
specified by "remote".
The format of the remote server string is defined by rsync(1). Note that there is no
way to supply a password or passphrase so the target must be set up not to require
one.
The optional arguments are the same as those of "$g->rsync".
Globbing does not happen on the "src" parameter. In programs which use the API
directly you have to expand wildcards yourself (see "$g->glob_expand"). In guestfish
you can use the "glob" command (see "glob" in guestfish(1)), for example:
><fs> glob rsync-out /* rsync://remote/
$g->scrub_device ($device);
This command writes patterns over "device" to make data retrieval more difficult.
It is an interface to the scrub(1) program. See that manual page for more details.
$g->scrub_file ($file);
This command writes patterns over a file to make data retrieval more difficult.
The file is removed after scrubbing.
It is an interface to the scrub(1) program. See that manual page for more details.
$g->scrub_freespace ($dir);
This command creates the directory "dir" and then fills it with files until the
filesystem is full, and scrubs the files as for "$g->scrub_file", and deletes them.
The intention is to scrub any free space on the partition containing "dir".
It is an interface to the scrub(1) program. See that manual page for more details.
$g->set_append ($append);
This function is used to add additional options to the libguestfs appliance kernel
command line.
The default is "NULL" unless overridden by setting "LIBGUESTFS_APPEND" environment
variable.
Setting "append" to "NULL" means no additional options are passed (libguestfs always
adds a few of its own).
$g->set_attach_method ($backend);
Set the method that libguestfs uses to connect to the backend guestfsd daemon.
See "BACKEND" in guestfs(3).
This function is deprecated. In new code, use the "set_backend" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->set_autosync ($autosync);
If "autosync" is true, this enables autosync. Libguestfs will make a best effort
attempt to make filesystems consistent and synchronized when the handle is closed
(also if the program exits without closing handles).
This is enabled by default (since libguestfs 1.5.24, previously it was disabled by
default).
$g->set_backend ($backend);
Set the method that libguestfs uses to connect to the backend guestfsd daemon.
This handle property was previously called the "attach method".
See "BACKEND" in guestfs(3).
$g->set_backend_setting ($name, $val);
Append "name=value" to the backend settings string list. However if a string already
exists matching "name" or beginning with "name=", then that setting is replaced.
See "BACKEND" in guestfs(3), "BACKEND SETTINGS" in guestfs(3).
$g->set_backend_settings (\@settings);
Set a list of zero or more settings which are passed through to the current backend.
Each setting is a string which is interpreted in a backend-specific way, or ignored if
not understood by the backend.
The default value is an empty list, unless the environment variable
"LIBGUESTFS_BACKEND_SETTINGS" was set when the handle was created. This environment
variable contains a colon-separated list of settings.
This call replaces all backend settings. If you want to replace a single backend
setting, see "$g->set_backend_setting". If you want to clear a single backend
setting, see "$g->clear_backend_setting".
See "BACKEND" in guestfs(3), "BACKEND SETTINGS" in guestfs(3).
$g->set_cachedir ($cachedir);
Set the directory used by the handle to store the appliance cache, when using a
supermin appliance. The appliance is cached and shared between all handles which have
the same effective user ID.
The environment variables "LIBGUESTFS_CACHEDIR" and "TMPDIR" control the default
value: If "LIBGUESTFS_CACHEDIR" is set, then that is the default. Else if "TMPDIR" is
set, then that is the default. Else /var/tmp is the default.
$g->set_direct ($direct);
If the direct appliance mode flag is enabled, then stdin and stdout are passed
directly through to the appliance once it is launched.
One consequence of this is that log messages aren't caught by the library and handled
by "$g->set_log_message_callback", but go straight to stdout.
You probably don't want to use this unless you know what you are doing.
The default is disabled.
$g->set_e2attrs ($file, $attrs [, clear => $clear]);
This sets or clears the file attributes "attrs" associated with the inode file.
"attrs" is a string of characters representing file attributes. See "$g->get_e2attrs"
for a list of possible attributes. Not all attributes can be changed.
If optional boolean "clear" is not present or false, then the "attrs" listed are set
in the inode.
If "clear" is true, then the "attrs" listed are cleared in the inode.
In both cases, other attributes not present in the "attrs" string are left unchanged.
These attributes are only present when the file is located on an ext2/3/4 filesystem.
Using this call on other filesystem types will result in an error.
$g->set_e2generation ($file, $generation);
This sets the ext2 file generation of a file.
See "$g->get_e2generation".
$g->set_e2label ($device, $label);
This sets the ext2/3/4 filesystem label of the filesystem on "device" to "label".
Filesystem labels are limited to 16 characters.
You can use either "$g->tune2fs_l" or "$g->get_e2label" to return the existing label
on a filesystem.
This function is deprecated. In new code, use the "set_label" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->set_e2uuid ($device, $uuid);
This sets the ext2/3/4 filesystem UUID of the filesystem on "device" to "uuid". The
format of the UUID and alternatives such as "clear", "random" and "time" are described
in the tune2fs(8) manpage.
You can use "$g->vfs_uuid" to return the existing UUID of a filesystem.
This function is deprecated. In new code, use the "set_uuid" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->set_hv ($hv);
Set the hypervisor binary that we will use. The hypervisor depends on the backend,
but is usually the location of the qemu/KVM hypervisor. For the uml backend, it is
the location of the "linux" or "vmlinux" binary.
The default is chosen when the library was compiled by the configure script.
You can also override this by setting the "LIBGUESTFS_HV" environment variable.
Note that you should call this function as early as possible after creating the
handle. This is because some pre-launch operations depend on testing qemu features
(by running "qemu -help"). If the qemu binary changes, we don't retest features, and
so you might see inconsistent results. Using the environment variable "LIBGUESTFS_HV"
is safest of all since that picks the qemu binary at the same time as the handle is
created.
$g->set_identifier ($identifier);
This is an informative string which the caller may optionally set in the handle. It
is printed in various places, allowing the current handle to be identified in
debugging output.
One important place is when tracing is enabled. If the identifier string is not an
empty string, then trace messages change from this:
libguestfs: trace: get_tmpdir
libguestfs: trace: get_tmpdir = "/tmp"
to this:
libguestfs: trace: ID: get_tmpdir
libguestfs: trace: ID: get_tmpdir = "/tmp"
where "ID" is the identifier string set by this call.
The identifier must only contain alphanumeric ASCII characters, underscore and minus
sign. The default is the empty string.
See also "$g->set_program", "$g->set_trace", "$g->get_identifier".
$g->set_label ($mountable, $label);
Set the filesystem label on "mountable" to "label".
Only some filesystem types support labels, and libguestfs supports setting labels on
only a subset of these.
ext2, ext3, ext4
Labels are limited to 16 bytes.
NTFS
Labels are limited to 128 unicode characters.
XFS The label is limited to 12 bytes. The filesystem must not be mounted when trying
to set the label.
btrfs
The label is limited to 255 bytes and some characters are not allowed. Setting
the label on a btrfs subvolume will set the label on its parent filesystem. The
filesystem must not be mounted when trying to set the label.
fat The label is limited to 11 bytes.
If there is no support for changing the label for the type of the specified
filesystem, set_label will fail and set errno as ENOTSUP.
To read the label on a filesystem, call "$g->vfs_label".
$g->set_libvirt_requested_credential ($index, $cred);
After requesting the "index"'th credential from the user, call this function to pass
the answer back to libvirt.
See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.
$g->set_libvirt_supported_credentials (\@creds);
Call this function before setting an event handler for "GUESTFS_EVENT_LIBVIRT_AUTH",
to supply the list of credential types that the program knows how to process.
The "creds" list must be a non-empty list of strings. Possible strings are:
"username"
"authname"
"language"
"cnonce"
"passphrase"
"echoprompt"
"noechoprompt"
"realm"
"external"
See libvirt documentation for the meaning of these credential types.
See "LIBVIRT AUTHENTICATION" in guestfs(3) for documentation and example code.
$g->set_memsize ($memsize);
This sets the memory size in megabytes allocated to the hypervisor. This only has any
effect if called before "$g->launch".
You can also change this by setting the environment variable "LIBGUESTFS_MEMSIZE"
before the handle is created.
For more information on the architecture of libguestfs, see guestfs(3).
$g->set_network ($network);
If "network" is true, then the network is enabled in the libguestfs appliance. The
default is false.
This affects whether commands are able to access the network (see "RUNNING COMMANDS"
in guestfs(3)).
You must call this before calling "$g->launch", otherwise it has no effect.
$g->set_path ($searchpath);
Set the path that libguestfs searches for kernel and initrd.img.
The default is "$libdir/guestfs" unless overridden by setting "LIBGUESTFS_PATH"
environment variable.
Setting "path" to "NULL" restores the default path.
$g->set_pgroup ($pgroup);
If "pgroup" is true, child processes are placed into their own process group.
The practical upshot of this is that signals like "SIGINT" (from users pressing "^C")
won't be received by the child process.
The default for this flag is false, because usually you want "^C" to kill the
subprocess. Guestfish sets this flag to true when used interactively, so that "^C"
can cancel long-running commands gracefully (see "$g->user_cancel").
$g->set_program ($program);
Set the program name. This is an informative string which the main program may
optionally set in the handle.
When the handle is created, the program name in the handle is set to the basename from
"argv[0]". If that was not possible, it is set to the empty string (but never
"NULL").
$g->set_qemu ($hv);
Set the hypervisor binary (usually qemu) that we will use.
The default is chosen when the library was compiled by the configure script.
You can also override this by setting the "LIBGUESTFS_HV" environment variable.
Setting "hv" to "NULL" restores the default qemu binary.
Note that you should call this function as early as possible after creating the
handle. This is because some pre-launch operations depend on testing qemu features
(by running "qemu -help"). If the qemu binary changes, we don't retest features, and
so you might see inconsistent results. Using the environment variable "LIBGUESTFS_HV"
is safest of all since that picks the qemu binary at the same time as the handle is
created.
This function is deprecated. In new code, use the "set_hv" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->set_recovery_proc ($recoveryproc);
If this is called with the parameter "false" then "$g->launch" does not create a
recovery process. The purpose of the recovery process is to stop runaway hypervisor
processes in the case where the main program aborts abruptly.
This only has any effect if called before "$g->launch", and the default is true.
About the only time when you would want to disable this is if the main process will
fork itself into the background ("daemonize" itself). In this case the recovery
process thinks that the main program has disappeared and so kills the hypervisor,
which is not very helpful.
$g->set_selinux ($selinux);
This sets the selinux flag that is passed to the appliance at boot time. The default
is "selinux=0" (disabled).
Note that if SELinux is enabled, it is always in Permissive mode ("enforcing=0").
For more information on the architecture of libguestfs, see guestfs(3).
$g->set_smp ($smp);
Change the number of virtual CPUs assigned to the appliance. The default is 1.
Increasing this may improve performance, though often it has no effect.
This function must be called before "$g->launch".
$g->set_tmpdir ($tmpdir);
Set the directory used by the handle to store temporary files.
The environment variables "LIBGUESTFS_TMPDIR" and "TMPDIR" control the default value:
If "LIBGUESTFS_TMPDIR" is set, then that is the default. Else if "TMPDIR" is set,
then that is the default. Else /tmp is the default.
$g->set_trace ($trace);
If the command trace flag is set to 1, then libguestfs calls, parameters and return
values are traced.
If you want to trace C API calls into libguestfs (and other libraries) then possibly a
better way is to use the external ltrace(1) command.
Command traces are disabled unless the environment variable "LIBGUESTFS_TRACE" is
defined and set to 1.
Trace messages are normally sent to "stderr", unless you register a callback to send
them somewhere else (see "$g->set_event_callback").
$g->set_uuid ($device, $uuid);
Set the filesystem UUID on "device" to "uuid". If this fails and the errno is
ENOTSUP, means that there is no support for changing the UUID for the type of the
specified filesystem.
Only some filesystem types support setting UUIDs.
To read the UUID on a filesystem, call "$g->vfs_uuid".
$g->set_uuid_random ($device);
Set the filesystem UUID on "device" to a random UUID. If this fails and the errno is
ENOTSUP, means that there is no support for changing the UUID for the type of the
specified filesystem.
Only some filesystem types support setting UUIDs.
To read the UUID on a filesystem, call "$g->vfs_uuid".
$g->set_verbose ($verbose);
If "verbose" is true, this turns on verbose messages.
Verbose messages are disabled unless the environment variable "LIBGUESTFS_DEBUG" is
defined and set to 1.
Verbose messages are normally sent to "stderr", unless you register a callback to send
them somewhere else (see "$g->set_event_callback").
$g->setcon ($context);
This sets the SELinux security context of the daemon to the string "context".
See the documentation about SELINUX in guestfs(3).
$g->setxattr ($xattr, $val, $vallen, $path);
This call sets the extended attribute named "xattr" of the file "path" to the value
"val" (of length "vallen"). The value is arbitrary 8 bit data.
See also: "$g->lsetxattr", attr(5).
$g->sfdisk ($device, $cyls, $heads, $sectors, \@lines);
This is a direct interface to the sfdisk(8) program for creating partitions on block
devices.
"device" should be a block device, for example /dev/sda.
"cyls", "heads" and "sectors" are the number of cylinders, heads and sectors on the
device, which are passed directly to sfdisk as the -C, -H and -S parameters. If you
pass 0 for any of these, then the corresponding parameter is omitted. Usually for
'large' disks, you can just pass 0 for these, but for small (floppy-sized) disks,
sfdisk (or rather, the kernel) cannot work out the right geometry and you will need to
tell it.
"lines" is a list of lines that we feed to "sfdisk". For more information refer to
the sfdisk(8) manpage.
To create a single partition occupying the whole disk, you would pass "lines" as a
single element list, when the single element being the string "," (comma).
See also: "$g->sfdisk_l", "$g->sfdisk_N", "$g->part_init"
This function is deprecated. In new code, use the "part_add" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->sfdiskM ($device, \@lines);
This is a simplified interface to the "$g->sfdisk" command, where partition sizes are
specified in megabytes only (rounded to the nearest cylinder) and you don't need to
specify the cyls, heads and sectors parameters which were rarely if ever used anyway.
See also: "$g->sfdisk", the sfdisk(8) manpage and "$g->part_disk"
This function is deprecated. In new code, use the "part_add" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->sfdisk_N ($device, $partnum, $cyls, $heads, $sectors, $line);
This runs sfdisk(8) option to modify just the single partition "n" (note: "n" counts
from 1).
For other parameters, see "$g->sfdisk". You should usually pass 0 for the
cyls/heads/sectors parameters.
See also: "$g->part_add"
This function is deprecated. In new code, use the "part_add" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$partitions = $g->sfdisk_disk_geometry ($device);
This displays the disk geometry of "device" read from the partition table. Especially
in the case where the underlying block device has been resized, this can be different
from the kernel's idea of the geometry (see "$g->sfdisk_kernel_geometry").
The result is in human-readable format, and not designed to be parsed.
$partitions = $g->sfdisk_kernel_geometry ($device);
This displays the kernel's idea of the geometry of "device".
The result is in human-readable format, and not designed to be parsed.
$partitions = $g->sfdisk_l ($device);
This displays the partition table on "device", in the human-readable output of the
sfdisk(8) command. It is not intended to be parsed.
See also: "$g->part_list"
This function is deprecated. In new code, use the "part_list" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$output = $g->sh ($command);
This call runs a command from the guest filesystem via the guest's /bin/sh.
This is like "$g->command", but passes the command to:
/bin/sh -c "command"
Depending on the guest's shell, this usually results in wildcards being expanded,
shell expressions being interpolated and so on.
All the provisos about "$g->command" apply to this call.
@lines = $g->sh_lines ($command);
This is the same as "$g->sh", but splits the result into a list of lines.
See also: "$g->command_lines"
$g->shutdown ();
This is the opposite of "$g->launch". It performs an orderly shutdown of the backend
process(es). If the autosync flag is set (which is the default) then the disk image
is synchronized.
If the subprocess exits with an error then this function will return an error, which
should not be ignored (it may indicate that the disk image could not be written out
properly).
It is safe to call this multiple times. Extra calls are ignored.
This call does not close or free up the handle. You still need to call "$g->close"
afterwards.
"$g->close" will call this if you don't do it explicitly, but note that any errors are
ignored in that case.
$g->sleep ($secs);
Sleep for "secs" seconds.
%statbuf = $g->stat ($path);
Returns file information for the given "path".
This is the same as the stat(2) system call.
This function is deprecated. In new code, use the "statns" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
%statbuf = $g->statns ($path);
Returns file information for the given "path".
This is the same as the stat(2) system call.
%statbuf = $g->statvfs ($path);
Returns file system statistics for any mounted file system. "path" should be a file
or directory in the mounted file system (typically it is the mount point itself, but
it doesn't need to be).
This is the same as the statvfs(2) system call.
@stringsout = $g->strings ($path);
This runs the strings(1) command on a file and returns the list of printable strings
found.
The "strings" command has, in the past, had problems with parsing untrusted files.
These are mitigated in the current version of libguestfs, but see "CVE-2014-8484" in
guestfs(3).
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
@stringsout = $g->strings_e ($encoding, $path);
This is like the "$g->strings" command, but allows you to specify the encoding of
strings that are looked for in the source file "path".
Allowed encodings are:
s Single 7-bit-byte characters like ASCII and the ASCII-compatible parts of
ISO-8859-X (this is what "$g->strings" uses).
S Single 8-bit-byte characters.
b 16-bit big endian strings such as those encoded in UTF-16BE or UCS-2BE.
l (lower case letter L)
16-bit little endian such as UTF-16LE and UCS-2LE. This is useful for examining
binaries in Windows guests.
B 32-bit big endian such as UCS-4BE.
L 32-bit little endian such as UCS-4LE.
The returned strings are transcoded to UTF-8.
The "strings" command has, in the past, had problems with parsing untrusted files.
These are mitigated in the current version of libguestfs, but see "CVE-2014-8484" in
guestfs(3).
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$g->swapoff_device ($device);
This command disables the libguestfs appliance swap device or partition named
"device". See "$g->swapon_device".
$g->swapoff_file ($file);
This command disables the libguestfs appliance swap on file.
$g->swapoff_label ($label);
This command disables the libguestfs appliance swap on labeled swap partition.
$g->swapoff_uuid ($uuid);
This command disables the libguestfs appliance swap partition with the given UUID.
$g->swapon_device ($device);
This command enables the libguestfs appliance to use the swap device or partition
named "device". The increased memory is made available for all commands, for example
those run using "$g->command" or "$g->sh".
Note that you should not swap to existing guest swap partitions unless you know what
you are doing. They may contain hibernation information, or other information that
the guest doesn't want you to trash. You also risk leaking information about the host
to the guest this way. Instead, attach a new host device to the guest and swap on
that.
$g->swapon_file ($file);
This command enables swap to a file. See "$g->swapon_device" for other notes.
$g->swapon_label ($label);
This command enables swap to a labeled swap partition. See "$g->swapon_device" for
other notes.
$g->swapon_uuid ($uuid);
This command enables swap to a swap partition with the given UUID. See
"$g->swapon_device" for other notes.
$g->sync ();
This syncs the disk, so that any writes are flushed through to the underlying disk
image.
You should always call this if you have modified a disk image, before closing the
handle.
$g->syslinux ($device [, directory => $directory]);
Install the SYSLINUX bootloader on "device".
The device parameter must be either a whole disk formatted as a FAT filesystem, or a
partition formatted as a FAT filesystem. In the latter case, the partition should be
marked as "active" ("$g->part_set_bootable") and a Master Boot Record must be
installed (eg. using "$g->pwrite_device") on the first sector of the whole disk. The
SYSLINUX package comes with some suitable Master Boot Records. See the syslinux(1)
man page for further information.
The optional arguments are:
directory
Install SYSLINUX in the named subdirectory, instead of in the root directory of
the FAT filesystem.
Additional configuration can be supplied to SYSLINUX by placing a file called
syslinux.cfg on the FAT filesystem, either in the root directory, or under directory
if that optional argument is being used. For further information about the contents
of this file, see syslinux(1).
See also "$g->extlinux".
@lines = $g->tail ($path);
This command returns up to the last 10 lines of a file as a list of strings.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
@lines = $g->tail_n ($nrlines, $path);
If the parameter "nrlines" is a positive number, this returns the last "nrlines" lines
of the file "path".
If the parameter "nrlines" is a negative number, this returns lines from the file
"path", starting with the "-nrlines"th line.
If the parameter "nrlines" is zero, this returns an empty list.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
$g->tar_in ($tarfile, $directory [, compress => $compress] [, xattrs => $xattrs] [,
selinux => $selinux] [, acls => $acls]);
This command uploads and unpacks local file "tarfile" into directory.
The optional "compress" flag controls compression. If not given, then the input
should be an uncompressed tar file. Otherwise one of the following strings may be
given to select the compression type of the input file: "compress", "gzip", "bzip2",
"xz", "lzop". (Note that not all builds of libguestfs will support all of these
compression types).
The other optional arguments are:
"xattrs"
If set to true, extended attributes are restored from the tar file.
"selinux"
If set to true, SELinux contexts are restored from the tar file.
"acls"
If set to true, POSIX ACLs are restored from the tar file.
$g->tar_in_opts ($tarfile, $directory [, compress => $compress] [, xattrs => $xattrs] [,
selinux => $selinux] [, acls => $acls]);
This is an alias of "tar_in".
$g->tar_out ($directory, $tarfile [, compress => $compress] [, numericowner =>
$numericowner] [, excludes => $excludes] [, xattrs => $xattrs] [, selinux => $selinux] [,
acls => $acls]);
This command packs the contents of directory and downloads it to local file "tarfile".
The optional "compress" flag controls compression. If not given, then the output will
be an uncompressed tar file. Otherwise one of the following strings may be given to
select the compression type of the output file: "compress", "gzip", "bzip2", "xz",
"lzop". (Note that not all builds of libguestfs will support all of these compression
types).
The other optional arguments are:
"excludes"
A list of wildcards. Files are excluded if they match any of the wildcards.
"numericowner"
If set to true, the output tar file will contain UID/GID numbers instead of
user/group names.
"xattrs"
If set to true, extended attributes are saved in the output tar.
"selinux"
If set to true, SELinux contexts are saved in the output tar.
"acls"
If set to true, POSIX ACLs are saved in the output tar.
$g->tar_out_opts ($directory, $tarfile [, compress => $compress] [, numericowner =>
$numericowner] [, excludes => $excludes] [, xattrs => $xattrs] [, selinux => $selinux] [,
acls => $acls]);
This is an alias of "tar_out".
$g->tgz_in ($tarball, $directory);
This command uploads and unpacks local file "tarball" (a gzip compressed tar file)
into directory.
This function is deprecated. In new code, use the "tar_in" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->tgz_out ($directory, $tarball);
This command packs the contents of directory and downloads it to local file "tarball".
This function is deprecated. In new code, use the "tar_out" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->touch ($path);
Touch acts like the touch(1) command. It can be used to update the timestamps on a
file, or, if the file does not exist, to create a new zero-length file.
This command only works on regular files, and will fail on other file types such as
directories, symbolic links, block special etc.
$g->truncate ($path);
This command truncates "path" to a zero-length file. The file must exist already.
$g->truncate_size ($path, $size);
This command truncates "path" to size "size" bytes. The file must exist already.
If the current file size is less than "size" then the file is extended to the required
size with zero bytes. This creates a sparse file (ie. disk blocks are not allocated
for the file until you write to it). To create a non-sparse file of zeroes, use
"$g->fallocate64" instead.
$g->tune2fs ($device [, force => $force] [, maxmountcount => $maxmountcount] [, mountcount
=> $mountcount] [, errorbehavior => $errorbehavior] [, group => $group] [,
intervalbetweenchecks => $intervalbetweenchecks] [, reservedblockspercentage =>
$reservedblockspercentage] [, lastmounteddirectory => $lastmounteddirectory] [,
reservedblockscount => $reservedblockscount] [, user => $user]);
This call allows you to adjust various filesystem parameters of an ext2/ext3/ext4
filesystem called "device".
The optional parameters are:
"force"
Force tune2fs to complete the operation even in the face of errors. This is the
same as the tune2fs "-f" option.
"maxmountcount"
Set the number of mounts after which the filesystem is checked by e2fsck(8). If
this is 0 then the number of mounts is disregarded. This is the same as the
tune2fs "-c" option.
"mountcount"
Set the number of times the filesystem has been mounted. This is the same as the
tune2fs "-C" option.
"errorbehavior"
Change the behavior of the kernel code when errors are detected. Possible values
currently are: "continue", "remount-ro", "panic". In practice these options don't
really make any difference, particularly for write errors.
This is the same as the tune2fs "-e" option.
"group"
Set the group which can use reserved filesystem blocks. This is the same as the
tune2fs "-g" option except that it can only be specified as a number.
"intervalbetweenchecks"
Adjust the maximal time between two filesystem checks (in seconds). If the option
is passed as 0 then time-dependent checking is disabled.
This is the same as the tune2fs "-i" option.
"reservedblockspercentage"
Set the percentage of the filesystem which may only be allocated by privileged
processes. This is the same as the tune2fs "-m" option.
"lastmounteddirectory"
Set the last mounted directory. This is the same as the tune2fs "-M" option.
"reservedblockscount" Set the number of reserved filesystem blocks. This is the same
as the tune2fs "-r" option.
"user"
Set the user who can use the reserved filesystem blocks. This is the same as the
tune2fs "-u" option except that it can only be specified as a number.
To get the current values of filesystem parameters, see "$g->tune2fs_l". For precise
details of how tune2fs works, see the tune2fs(8) man page.
%superblock = $g->tune2fs_l ($device);
This returns the contents of the ext2, ext3 or ext4 filesystem superblock on "device".
It is the same as running "tune2fs -l device". See tune2fs(8) manpage for more
details. The list of fields returned isn't clearly defined, and depends on both the
version of "tune2fs" that libguestfs was built against, and the filesystem itself.
$g->txz_in ($tarball, $directory);
This command uploads and unpacks local file "tarball" (an xz compressed tar file) into
directory.
This function is deprecated. In new code, use the "tar_in" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->txz_out ($directory, $tarball);
This command packs the contents of directory and downloads it to local file "tarball"
(as an xz compressed tar archive).
This function is deprecated. In new code, use the "tar_out" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$oldmask = $g->umask ($mask);
This function sets the mask used for creating new files and device nodes to "mask &
0777".
Typical umask values would be 022 which creates new files with permissions like
"-rw-r--r--" or "-rwxr-xr-x", and 002 which creates new files with permissions like
"-rw-rw-r--" or "-rwxrwxr-x".
The default umask is 022. This is important because it means that directories and
device nodes will be created with 0644 or 0755 mode even if you specify 0777.
See also "$g->get_umask", umask(2), "$g->mknod", "$g->mkdir".
This call returns the previous umask.
$g->umount ($pathordevice [, force => $force] [, lazyunmount => $lazyunmount]);
This unmounts the given filesystem. The filesystem may be specified either by its
mountpoint (path) or the device which contains the filesystem.
$g->umount_opts ($pathordevice [, force => $force] [, lazyunmount => $lazyunmount]);
This is an alias of "umount".
$g->umount_all ();
This unmounts all mounted filesystems.
Some internal mounts are not unmounted by this call.
$g->umount_local ([retry => $retry]);
If libguestfs is exporting the filesystem on a local mountpoint, then this unmounts
it.
See "MOUNT LOCAL" in guestfs(3) for full documentation.
$g->upload ($filename, $remotefilename);
Upload local file filename to remotefilename on the filesystem.
filename can also be a named pipe.
See also "$g->download".
$g->upload_offset ($filename, $remotefilename, $offset);
Upload local file filename to remotefilename on the filesystem.
remotefilename is overwritten starting at the byte "offset" specified. The intention
is to overwrite parts of existing files or devices, although if a non-existent file is
specified then it is created with a "hole" before "offset". The size of the data
written is implicit in the size of the source filename.
Note that there is no limit on the amount of data that can be uploaded with this call,
unlike with "$g->pwrite", and this call always writes the full amount unless an error
occurs.
See also "$g->upload", "$g->pwrite".
$g->user_cancel ();
This function cancels the current upload or download operation.
Unlike most other libguestfs calls, this function is signal safe and thread safe. You
can call it from a signal handler or from another thread, without needing to do any
locking.
The transfer that was in progress (if there is one) will stop shortly afterwards, and
will return an error. The errno (see "guestfs_last_errno") is set to "EINTR", so you
can test for this to find out if the operation was cancelled or failed because of
another error.
No cleanup is performed: for example, if a file was being uploaded then after
cancellation there may be a partially uploaded file. It is the caller's
responsibility to clean up if necessary.
There are two common places that you might call "$g->user_cancel":
In an interactive text-based program, you might call it from a "SIGINT" signal handler
so that pressing "^C" cancels the current operation. (You also need to call
"guestfs_set_pgroup" so that child processes don't receive the "^C" signal).
In a graphical program, when the main thread is displaying a progress bar with a
cancel button, wire up the cancel button to call this function.
$g->utimens ($path, $atsecs, $atnsecs, $mtsecs, $mtnsecs);
This command sets the timestamps of a file with nanosecond precision.
"atsecs, atnsecs" are the last access time (atime) in secs and nanoseconds from the
epoch.
"mtsecs, mtnsecs" are the last modification time (mtime) in secs and nanoseconds from
the epoch.
If the *nsecs field contains the special value "-1" then the corresponding timestamp
is set to the current time. (The *secs field is ignored in this case).
If the *nsecs field contains the special value "-2" then the corresponding timestamp
is left unchanged. (The *secs field is ignored in this case).
%uts = $g->utsname ();
This returns the kernel version of the appliance, where this is available. This
information is only useful for debugging. Nothing in the returned structure is
defined by the API.
%version = $g->version ();
Return the libguestfs version number that the program is linked against.
Note that because of dynamic linking this is not necessarily the version of libguestfs
that you compiled against. You can compile the program, and then at runtime
dynamically link against a completely different libguestfs.so library.
This call was added in version 1.0.58. In previous versions of libguestfs there was
no way to get the version number. From C code you can use dynamic linker functions to
find out if this symbol exists (if it doesn't, then it's an earlier version).
The call returns a structure with four elements. The first three ("major", "minor"
and "release") are numbers and correspond to the usual version triplet. The fourth
element ("extra") is a string and is normally empty, but may be used for distro-
specific information.
To construct the original version string: "$major.$minor.$release$extra"
See also: "LIBGUESTFS VERSION NUMBERS" in guestfs(3).
Note: Don't use this call to test for availability of features. In enterprise
distributions we backport features from later versions into earlier versions, making
this an unreliable way to test for features. Use "$g->available" or
"$g->feature_available" instead.
$label = $g->vfs_label ($mountable);
This returns the label of the filesystem on "mountable".
If the filesystem is unlabeled, this returns the empty string.
To find a filesystem from the label, use "$g->findfs_label".
$sizeinbytes = $g->vfs_minimum_size ($mountable);
Get the minimum size of filesystem in bytes. This is the minimum possible size for
filesystem shrinking.
If getting minimum size of specified filesystem is not supported, this will fail and
set errno as ENOTSUP.
See also ntfsresize(8), resize2fs(8), btrfs(8), xfs_info(8).
$fstype = $g->vfs_type ($mountable);
This command gets the filesystem type corresponding to the filesystem on "mountable".
For most filesystems, the result is the name of the Linux VFS module which would be
used to mount this filesystem if you mounted it without specifying the filesystem
type. For example a string such as "ext3" or "ntfs".
$uuid = $g->vfs_uuid ($mountable);
This returns the filesystem UUID of the filesystem on "mountable".
If the filesystem does not have a UUID, this returns the empty string.
To find a filesystem from the UUID, use "$g->findfs_uuid".
$g->vg_activate ($activate, \@volgroups);
This command activates or (if "activate" is false) deactivates all logical volumes in
the listed volume groups "volgroups".
This command is the same as running "vgchange -a y|n volgroups..."
Note that if "volgroups" is an empty list then all volume groups are activated or
deactivated.
$g->vg_activate_all ($activate);
This command activates or (if "activate" is false) deactivates all logical volumes in
all volume groups.
This command is the same as running "vgchange -a y|n"
$g->vgchange_uuid ($vg);
Generate a new random UUID for the volume group "vg".
$g->vgchange_uuid_all ();
Generate new random UUIDs for all volume groups.
$g->vgcreate ($volgroup, \@physvols);
This creates an LVM volume group called "volgroup" from the non-empty list of physical
volumes "physvols".
@uuids = $g->vglvuuids ($vgname);
Given a VG called "vgname", this returns the UUIDs of all the logical volumes created
in this volume group.
You can use this along with "$g->lvs" and "$g->lvuuid" calls to associate logical
volumes and volume groups.
See also "$g->vgpvuuids".
$metadata = $g->vgmeta ($vgname);
"vgname" is an LVM volume group. This command examines the volume group and returns
its metadata.
Note that the metadata is an internal structure used by LVM, subject to change at any
time, and is provided for information only.
@uuids = $g->vgpvuuids ($vgname);
Given a VG called "vgname", this returns the UUIDs of all the physical volumes that
this volume group resides on.
You can use this along with "$g->pvs" and "$g->pvuuid" calls to associate physical
volumes and volume groups.
See also "$g->vglvuuids".
$g->vgremove ($vgname);
Remove an LVM volume group "vgname", (for example "VG").
This also forcibly removes all logical volumes in the volume group (if any).
$g->vgrename ($volgroup, $newvolgroup);
Rename a volume group "volgroup" with the new name "newvolgroup".
@volgroups = $g->vgs ();
List all the volumes groups detected. This is the equivalent of the vgs(8) command.
This returns a list of just the volume group names that were detected (eg.
"VolGroup00").
See also "$g->vgs_full".
@volgroups = $g->vgs_full ();
List all the volumes groups detected. This is the equivalent of the vgs(8) command.
The "full" version includes all fields.
$g->vgscan ();
This rescans all block devices and rebuilds the list of LVM physical volumes, volume
groups and logical volumes.
$uuid = $g->vguuid ($vgname);
This command returns the UUID of the LVM VG named "vgname".
$g->wait_ready ();
This function is a no op.
In versions of the API < 1.0.71 you had to call this function just after calling
"$g->launch" to wait for the launch to complete. However this is no longer necessary
because "$g->launch" now does the waiting.
If you see any calls to this function in code then you can just remove them, unless
you want to retain compatibility with older versions of the API.
This function is deprecated. In new code, use the "launch" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$chars = $g->wc_c ($path);
This command counts the characters in a file, using the "wc -c" external command.
$lines = $g->wc_l ($path);
This command counts the lines in a file, using the "wc -l" external command.
$words = $g->wc_w ($path);
This command counts the words in a file, using the "wc -w" external command.
$g->wipefs ($device);
This command erases filesystem or RAID signatures from the specified "device" to make
the filesystem invisible to libblkid.
This does not erase the filesystem itself nor any other data from the "device".
Compare with "$g->zero" which zeroes the first few blocks of a device.
$g->write ($path, $content);
This call creates a file called "path". The content of the file is the string
"content" (which can contain any 8 bit data).
See also "$g->write_append".
$g->write_append ($path, $content);
This call appends "content" to the end of file "path". If "path" does not exist, then
a new file is created.
See also "$g->write".
$g->write_file ($path, $content, $size);
This call creates a file called "path". The contents of the file is the string
"content" (which can contain any 8 bit data), with length "size".
As a special case, if "size" is 0 then the length is calculated using "strlen" (so in
this case the content cannot contain embedded ASCII NULs).
NB. Owing to a bug, writing content containing ASCII NUL characters does not work,
even if the length is specified.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "write" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->xfs_admin ($device [, extunwritten => $extunwritten] [, imgfile => $imgfile] [, v2log
=> $v2log] [, projid32bit => $projid32bit] [, lazycounter => $lazycounter] [, label =>
$label] [, uuid => $uuid]);
Change the parameters of the XFS filesystem on "device".
Devices that are mounted cannot be modified. Administrators must unmount filesystems
before this call can modify parameters.
Some of the parameters of a mounted filesystem can be examined and modified using the
"$g->xfs_info" and "$g->xfs_growfs" calls.
$g->xfs_growfs ($path [, datasec => $datasec] [, logsec => $logsec] [, rtsec => $rtsec] [,
datasize => $datasize] [, logsize => $logsize] [, rtsize => $rtsize] [, rtextsize =>
$rtextsize] [, maxpct => $maxpct]);
Grow the XFS filesystem mounted at "path".
The returned struct contains geometry information. Missing fields are returned as
"-1" (for numeric fields) or empty string.
%info = $g->xfs_info ($pathordevice);
"pathordevice" is a mounted XFS filesystem or a device containing an XFS filesystem.
This command returns the geometry of the filesystem.
The returned struct contains geometry information. Missing fields are returned as
"-1" (for numeric fields) or empty string.
$status = $g->xfs_repair ($device [, forcelogzero => $forcelogzero] [, nomodify =>
$nomodify] [, noprefetch => $noprefetch] [, forcegeometry => $forcegeometry] [, maxmem =>
$maxmem] [, ihashsize => $ihashsize] [, bhashsize => $bhashsize] [, agstride => $agstride]
[, logdev => $logdev] [, rtdev => $rtdev]);
Repair corrupt or damaged XFS filesystem on "device".
The filesystem is specified using the "device" argument which should be the device
name of the disk partition or volume containing the filesystem. If given the name of
a block device, "xfs_repair" will attempt to find the raw device associated with the
specified block device and will use the raw device instead.
Regardless, the filesystem to be repaired must be unmounted, otherwise, the resulting
filesystem may be inconsistent or corrupt.
The returned status indicates whether filesystem corruption was detected (returns 1)
or was not detected (returns 0).
@lines = $g->zegrep ($regex, $path);
This calls the external "zegrep" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@lines = $g->zegrepi ($regex, $path);
This calls the external "zegrep -i" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$g->zero ($device);
This command writes zeroes over the first few blocks of "device".
How many blocks are zeroed isn't specified (but it's not enough to securely wipe the
device). It should be sufficient to remove any partition tables, filesystem
superblocks and so on.
If blocks are already zero, then this command avoids writing zeroes. This prevents
the underlying device from becoming non-sparse or growing unnecessarily.
See also: "$g->zero_device", "$g->scrub_device", "$g->is_zero_device"
$g->zero_device ($device);
This command writes zeroes over the entire "device". Compare with "$g->zero" which
just zeroes the first few blocks of a device.
If blocks are already zero, then this command avoids writing zeroes. This prevents
the underlying device from becoming non-sparse or growing unnecessarily.
$g->zero_free_space ($directory);
Zero the free space in the filesystem mounted on directory. The filesystem must be
mounted read-write.
The filesystem contents are not affected, but any free space in the filesystem is
freed.
Free space is not "trimmed". You may want to call "$g->fstrim" either as an
alternative to this, or after calling this, depending on your requirements.
$g->zerofree ($device);
This runs the zerofree program on "device". This program claims to zero unused inodes
and disk blocks on an ext2/3 filesystem, thus making it possible to compress the
filesystem more effectively.
You should not run this program if the filesystem is mounted.
It is possible that using this program can damage the filesystem or data on the
filesystem.
@lines = $g->zfgrep ($pattern, $path);
This calls the external "zfgrep" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@lines = $g->zfgrepi ($pattern, $path);
This calls the external "zfgrep -i" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
$description = $g->zfile ($meth, $path);
This command runs file after first decompressing "path" using "method".
"method" must be one of "gzip", "compress" or "bzip2".
Since 1.0.63, use "$g->file" instead which can now process compressed files.
This function is deprecated. In new code, use the "file" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@lines = $g->zgrep ($regex, $path);
This calls the external "zgrep" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
@lines = $g->zgrepi ($regex, $path);
This calls the external "zgrep -i" program and returns the matching lines.
Because of the message protocol, there is a transfer limit of somewhere between 2MB
and 4MB. See "PROTOCOL LIMITS" in guestfs(3).
This function is deprecated. In new code, use the "grep" call instead.
Deprecated functions will not be removed from the API, but the fact that they are
deprecated indicates that there are problems with correct use of these functions.
AVAILABILITY
From time to time we add new libguestfs APIs. Also some libguestfs APIs won't be
available in all builds of libguestfs (the Fedora build is full-featured, but other builds
may disable features). How do you test whether the APIs that your Perl program needs are
available in the version of "Sys::Guestfs" that you are using?
To test if a particular function is available in the "Sys::Guestfs" class, use the
ordinary Perl UNIVERSAL method "can(METHOD)" (see perlobj(1)). For example:
use Sys::Guestfs;
if (defined (Sys::Guestfs->can ("set_verbose"))) {
print "\$g->set_verbose is available\n";
}
Perl does not offer a way to list the arguments of a method, and from time to time we may
add extra arguments to calls that take optional arguments. For this reason, we provide a
global hash variable %guestfs_introspection which contains the arguments and their types
for each libguestfs method. The keys of this hash are the method names, and the values
are an hashref containing useful introspection information about the method (further
fields may be added to this in future).
use Sys::Guestfs;
$Sys::Guestfs::guestfs_introspection{mkfs}
=> {
ret => 'void', # return type
args => [ # required arguments
[ 'fstype', 'string', 0 ],
[ 'device', 'string(device)', 1 ],
],
optargs => { # optional arguments
blocksize => [ 'blocksize', 'int', 0 ],
features => [ 'features', 'string', 1 ],
inode => [ 'inode', 'int', 2 ],
sectorsize => [ 'sectorsize', 'int', 3 ],
},
name => "mkfs",
description => "make a filesystem",
}
To test if particular features are supported by the current build, use the
"feature_available" method like the example below. Note that the appliance must be
launched first.
$g->feature_available ( ["augeas"] );
For further discussion on this topic, refer to "AVAILABILITY" in guestfs(3).
STORING DATA IN THE HANDLE
The handle returned from "new" is a hash reference. The hash normally contains some
elements:
{
_g => [private data used by libguestfs],
_flags => [flags provided when creating the handle]
}
Callers can add other elements to this hash to store data for their own purposes. The
data lasts for the lifetime of the handle.
Any fields whose names begin with an underscore are reserved for private use by
libguestfs. We may add more in future.
It is recommended that callers prefix the name of their field(s) with some unique string,
to avoid conflicts with other users.
COPYRIGHT
Copyright (C) 2009-2019 Red Hat Inc.
LICENSE
Please see the file COPYING.LIB for the full license.
SEE ALSO
guestfs(3), guestfish(1), <http://libguestfs.org>.