NAME

       virt-edit - Edit a file in a virtual machine

SYNOPSIS

        virt-edit [--options] -d domname file [file ...]

        virt-edit [--options] -a disk.img [-a disk.img ...] file [file ...]

        virt-edit [-d domname|-a disk.img] file -e 'expr'

       Old-style:

        virt-edit domname file

        virt-edit disk.img [disk.img ...] file

WARNING

       You must not use "virt-edit" on live virtual machines.  If you do this, you risk disk corruption in the
       VM.  "virt-edit" tries to stop you from doing this, but doesn't catch all cases.

DESCRIPTION

       "virt-edit" is a command line tool to edit "file" where each "file" exists in the named virtual machine
       (or disk image).

       Multiple filenames can be given, in which case they are each edited in turn.  Each filename must be a
       full path, starting at the root directory (starting with '/').

       If you want to just view a file, use virt-cat(1).

       For more complex cases you should look at the guestfish(1) tool (see "USING GUESTFISH" below).

       "virt-edit" cannot be used to create a new file.  guestfish(1) can do that and much more.

EXAMPLES

       Edit the named files interactively:

        virt-edit -d mydomain /boot/grub/grub.conf

        virt-edit -d mydomain /etc/passwd

       For Windows guests, some Windows paths are understood:

        virt-edit -d mywindomain 'c:\autoexec.bat'

       If Perl is installed, you can also edit files non-interactively (see "NON-INTERACTIVE EDITING" below).
       To change the init default level to 5:

        virt-edit -d mydomain /etc/inittab -e 's/^id:.*/id:5:initdefault:/'

OPTIONS

       --help
           Display brief help.

       -a file
       --add file
           Add  file  which  should be a disk image from a virtual machine.  If the virtual machine has multiple
           block devices, you must supply all of them with separate -a options.

           The format of the disk image is auto-detected.  To override this and force a  particular  format  use
           the --format=.. option.

       -a URI
       --add URI
           Add a remote disk.  See "ADDING REMOTE STORAGE" in guestfish(1).

       -b extension
       --backup extension
           Create  a  backup of the original file in the guest disk image.  The backup has the original filename
           with "extension" added.

           Usually the first character of "extension" would be a dot "."  so you would write:

            virt-edit -b .orig [etc]

           By default, no backup file is made.

       -c URI
       --connect URI
           If using libvirt, connect to the given URI.  If omitted, then  we  connect  to  the  default  libvirt
           hypervisor.

           If you specify guest block devices directly, then libvirt is not used at all.

       -d guest
       --domain guest
           Add all the disks from the named libvirt guest.  Domain UUIDs can be used instead of names.

       --echo-keys
           When  prompting for keys and passphrases, virt-edit normally turns echoing off so you cannot see what
           you are typing.  If you are not worried about Tempest attacks and there is no one else  in  the  room
           you can specify this flag to see what you are typing.

       -e EXPR
       --edit EXPR
       --expr EXPR
           Instead  of launching the external editor, non-interactively apply the Perl expression "EXPR" to each
           line in the file.  See "NON-INTERACTIVE EDITING" below.

           Be careful to properly quote the expression to prevent it from being altered by the shell.

           Note that this option is only available when Perl 5 is installed.

       --format raw|qcow2|...
       --format
           The default for the -a option is to auto-detect the format of the disk image.  Using this forces  the
           disk  format  for  -a  options  which  follow  on  the command line.  Using --format with no argument
           switches back to auto-detection for subsequent -a options.

           For example:

            virt-edit --format=raw -a disk.img file

           forces raw format (no auto-detection) for "disk.img".

            virt-edit --format=raw -a disk.img --format -a another.img file

           forces raw format (no auto-detection) for "disk.img" and reverts to auto-detection for "another.img".

           If you have untrusted raw-format guest disk images, you should use this option to  specify  the  disk
           format.  This avoids a possible security problem with malicious guests (CVE-2010-3851).

       --keys-from-stdin
           Read  key  or  passphrase  parameters from stdin.  The default is to try to read passphrases from the
           user by opening "/dev/tty".

       -v
       --verbose
           Enable verbose messages for debugging.

       -V
       --version
           Display version number and exit.

       -x  Enable tracing of libguestfs API calls.

OLD-STYLE COMMAND LINE ARGUMENTS

       Previous versions of virt-edit allowed you to write either:

        virt-edit disk.img [disk.img ...] file

       or

        virt-edit guestname file

       whereas in this version you should use -a or -d respectively to avoid the confusing  case  where  a  disk
       image might have the same name as a guest.

       For compatibility the old style is still supported.

NON-INTERACTIVE EDITING

       "virt-edit"  normally calls out to $EDITOR (or vi) so the system administrator can interactively edit the
       file.

       There are two ways also to use "virt-edit" from scripts in order to make automated edits to files.  (Note
       that although you can use "virt-edit" like this, it's less error-prone to write  scripts  directly  using
       the libguestfs API and Augeas for configuration file editing.)

       The  first  method is to temporarily set $EDITOR to any script or program you want to run.  The script is
       invoked as "$EDITOR tmpfile" and it should update "tmpfile" in place however it likes.

       The second method is to use the -e parameter of "virt-edit" to run a short Perl snippet in the  style  of
       sed(1).  For example to replace all instances of "foo" with "bar" in a file:

        virt-edit -d domname filename -e 's/foo/bar/'

       The  full  power  of  Perl regular expressions can be used (see perlre(1)).  For example to delete root's
       password you could do:

        virt-edit -d domname /etc/passwd -e 's/^root:.*?:/root::/'

       What really happens is that the snippet is evaluated as a Perl expression for each line of the file.  The
       line, including the final "\n", is passed in  $_  and  the  expression  should  update  $_  or  leave  it
       unchanged.

       To  delete a line, set $_ to the empty string.  For example, to delete the "apache" user account from the
       password file you can do:

        virt-edit -d mydomain /etc/passwd -e '$_ = "" if /^apache:/'

       To insert a line, prepend or append it to $_.  However appending lines to the end of the file  is  rather
       difficult  this  way  since there is no concept of "last line of the file" - your expression just doesn't
       get called again.  You might want to use the first method (setting $EDITOR) if you want to do this.

       The variable $lineno contains the current line number.  As is traditional, the first line in the file  is
       number 1.

       The  return value from the expression is ignored, but the expression may call "die" in order to abort the
       whole program, leaving the original file untouched.

       Remember when matching the end of a line that $_ may contain the final "\n", or (for DOS  files)  "\r\n",
       or  if the file does not end with a newline then neither of these.  Thus to match or substitute some text
       at the end of a line, use this regular expression:

        /some text(\r?\n)?$/

       Alternately, use the perl "chomp" function, being careful not to chomp $_ itself (since that would remove
       all newlines from the file):

        my $m = $_; chomp $m; $m =~ /some text$/

WINDOWS PATHS

       "virt-edit" has a limited ability to understand Windows drive letters and paths (eg. "E:\foo\bar.txt").

       If and only if the guest is running Windows then:

       •   Drive letter prefixes like "C:" are resolved against the Windows Registry to the correct filesystem.

       •   Any backslash ("\") characters in the path are replaced with forward slashes so that  libguestfs  can
           process it.

       •   The path is resolved case insensitively to locate the file that should be edited.

       There are some known shortcomings:

       •   Some NTFS symbolic links may not be followed correctly.

       •   NTFS junction points that cross filesystems are not followed.

USING GUESTFISH

       guestfish(1) is a more powerful, lower level tool which you can use when "virt-edit" doesn't work.

       Using "virt-edit" is approximately equivalent to doing:

        guestfish --rw -i -d domname edit /file

       where "domname" is the name of the libvirt guest, and "/file" is the full path to the file.

       The  command  above  uses  libguestfs's  guest  inspection  feature  and  so does not work on guests that
       libguestfs cannot inspect, or on things like arbitrary disk images that don't contain guests.  To edit  a
       file on a disk image directly, use:

        guestfish --rw -a disk.img -m /dev/sda1 edit /file

       where  "disk.img"  is  the  disk  image, "/dev/sda1" is the filesystem within the disk image to edit, and
       "/file" is the full path to the file.

       "virt-edit" cannot create new files.  Use the guestfish commands "touch", "write" or "upload" instead:

        guestfish --rw -i -d domname touch /newfile

        guestfish --rw -i -d domname write /newfile "new content"

        guestfish --rw -i -d domname upload localfile /newfile

ENVIRONMENT VARIABLES

       "EDITOR"
           If set, this string is used as the editor.  It may contain arguments, eg. "emacs -nw"

           If not set, "vi" is used.

SHELL QUOTING

       Libvirt guest names can contain arbitrary characters, some of which have meaning to the shell such as "#"
       and space.  You may need to quote or escape these characters on the command line.  See the  shell  manual
       page sh(1) for details.

EXIT STATUS

       This program returns 0 if successful, or non-zero if there was an error.

SEE ALSO

       guestfs(3),  guestfish(1), virt-cat(1), virt-copy-in(1), virt-tar-in(1), http://libguestfs.org/, perl(1),
       perlre(1).

AUTHOR

       Richard W.M. Jones http://people.redhat.com/~rjones/

COPYRIGHT

       Copyright (C) 2009-2014 Red Hat Inc.

LICENSE

       This program is free software; you can redistribute it and/or modify  it  under  the  terms  of  the  GNU
       General  Public License as published by the Free Software Foundation; either version 2 of the License, or
       (at your option) any later version.

       This program is distributed in the hope that it will be useful, but WITHOUT ANY  WARRANTY;  without  even
       the  implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
       License for more details.

       You should have received a copy of the GNU General Public License along with this program; if not,  write
       to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.

BUGS

       To      get      a      list      of      bugs      against      libguestfs,      use      this     link:
       https://bugzilla.redhat.com/buglist.cgi?component=libguestfs&product=Virtualization+Tools

       To      report      a      new       bug       against       libguestfs,       use       this       link:
       https://bugzilla.redhat.com/enter_bug.cgi?component=libguestfs&product=Virtualization+Tools

       When reporting a bug, please supply:

       •   The version of libguestfs.

       •   Where you got libguestfs (eg. which Linux distro, compiled from source, etc)

       •   Describe the bug accurately and give a way to reproduce it.

       •   Run libguestfs-test-tool(1) and paste the complete, unedited output into the bug report.

libguestfs-1.24.5                                  2015-10-14                                       virt-edit(1)