Provided by: libarchive-dev_3.6.2-1ubuntu1.1_amd64 
NAME
archive_write_set_filter_option, archive_write_set_format_option, archive_write_set_option,
archive_write_set_options — functions controlling options for writing archives
LIBRARY
Streaming Archive Library (libarchive, -larchive)
SYNOPSIS
int
archive_write_set_filter_option(struct archive *, const char *module, const char *option,
const char *value);
int
archive_write_set_format_option(struct archive *, const char *module, const char *option,
const char *value);
int
archive_write_set_option(struct archive *, const char *module, const char *option,
const char *value);
int
archive_write_set_options(struct archive *, const char *options);
DESCRIPTION
These functions provide a way for libarchive clients to configure specific write modules.
archive_write_set_filter_option(), archive_write_set_format_option()
Specifies an option that will be passed to the currently-registered filters
(including decompression filters) or format readers.
If option and value are both NULL, these functions will do nothing and ARCHIVE_OK
will be returned. If option is NULL but value is not, these functions will do
nothing and ARCHIVE_FAILED will be returned.
If module is not NULL, option and value will be provided to the filter or reader
named module. The return value will be either ARCHIVE_OK if the option was
successfully handled or ARCHIVE_WARN if the option was unrecognized by the module or
could otherwise not be handled. If there is no such module, ARCHIVE_FAILED will be
returned.
If module is NULL, option and value will be provided to every registered module. If
any module returns ARCHIVE_FATAL, this value will be returned immediately.
Otherwise, ARCHIVE_OK will be returned if any module accepts the option, and
ARCHIVE_FAILED in all other cases.
archive_write_set_option()
Calls archive_write_set_format_option(), then archive_write_set_filter_option(). If
either function returns ARCHIVE_FATAL, ARCHIVE_FATAL will be returned immediately.
Otherwise, the greater of the two values will be returned.
archive_write_set_options()
options is a comma-separated list of options. If options is NULL or empty,
ARCHIVE_OK will be returned immediately.
Individual options have one of the following forms:
option=value
The option/value pair will be provided to every module. Modules that do not
accept an option with this name will ignore it.
option The option will be provided to every module with a value of “1”.
!option
The option will be provided to every module with a NULL value.
module:option=value, module:option, module:!option
As above, but the corresponding option and value will be provided only to
modules whose name matches module.
OPTIONS
Filter b64encode
mode The value is interpreted as octal digits specifying the file mode.
name The value specifies the file name.
Filter bzip2
compression-level
The value is interpreted as a decimal integer specifying the bzip2
compression level. Supported values are from 1 to 9.
Filter gzip
compression-level
The value is interpreted as a decimal integer specifying the gzip
compression level. Supported values are from 0 to 9.
timestamp
Store timestamp. This is enabled by default.
Filter lrzip
compression=type
Use type as compression method. Supported values are “bzip2”, “gzipi”,
“lzo” (ultra fast), and “zpaq” (best, extremely slow).
compression-level
The value is interpreted as a decimal integer specifying the lrzip
compression level. Supported values are from 1 to 9.
Filter lz4
compression-level
The value is interpreted as a decimal integer specifying the lz4 compression
level. Supported values are from 0 to 9.
stream-checksum
Enable stream checksum. This is enabled by default.
block-checksum
Enable block checksum. This is disabled by default.
block-size
The value is interpreted as a decimal integer specifying the lz4 compression
block size. Supported values are from 4 to 7 (default).
block-dependence
Use the previous block of the block being compressed for a compression
dictionary to improve compression ratio. This is disabled by default.
Filter lzop
compression-level
The value is interpreted as a decimal integer specifying the lzop
compression level. Supported values are from 1 to 9.
Filter uuencode
mode The value is interpreted as octal digits specifying the file mode.
name The value specifies the file name.
Filter xz
compression-level
The value is interpreted as a decimal integer specifying the compression
level. Supported values are from 0 to 9.
threads
The value is interpreted as a decimal integer specifying the number of
threads for multi-threaded lzma compression. If supported, the default
value is read from lzma_cputhreads().
Filter zstd
compression-level
The value is interpreted as a decimal integer specifying the compression
level. Supported values depend on the library version, common values are
from 1 to 22.
Format 7zip
compression
The value is one of “store”, “deflate”, “bzip2”, “lzma1”, “lzma2” or “ppmd”
to indicate how the following entries should be compressed. Note that this
setting is ignored for directories, symbolic links, and other special
entries.
compression-level
The value is interpreted as a decimal integer specifying the compression
level. Values between 0 and 9 are supported. The interpretation of the
compression level depends on the chosen compression method.
Format bin
hdrcharset
The value is used as a character set name that will be used when translating
file names.
Format gnutar
hdrcharset
The value is used as a character set name that will be used when translating
file, group and user names.
Format iso9660 - volume metadata
These options are used to set standard ISO9660 metadata.
abstract-file=filename
The file with the specified name will be identified in the ISO9660 metadata
as holding the abstract for this volume. Default: none.
application-id=filename
The file with the specified name will be identified in the ISO9660 metadata
as holding the application identifier for this volume. Default: none.
biblio-file=filename
The file with the specified name will be identified in the ISO9660 metadata
as holding the bibliography for this volume. Default: none.
copyright-file=filename
The file with the specified name will be identified in the ISO9660 metadata
as holding the copyright for this volume. Default: none.
publisher=filename
The file with the specified name will be identified in the ISO9660 metadata
as holding the publisher information for this volume. Default: none.
volume-id=string
The specified string will be used as the Volume Identifier in the ISO9660
metadata. It is limited to 32 bytes. Default: none.
Format iso9660 - boot support
These options are used to make an ISO9660 image that can be directly booted on
various systems.
boot=filename
The file matching this name will be used as the El Torito boot image file.
boot-catalog=name
The name that will be used for the El Torito boot catalog. Default:
boot.catalog
boot-info-table
The boot image file provided by the boot=filename option will be edited with
appropriate boot information in bytes 8 through 64. Default: disabled
boot-load-seg=hexadecimal-number
The load segment for a no-emulation boot image.
boot-load-size=decimal-number
The number of "virtual" 512-byte sectors to be loaded from a no-emulation
boot image. Some very old BIOSes can only load very small images, setting
this value to 4 will often allow such BIOSes to load the first part of the
boot image (which will then need to be intelligent enough to load the rest
of itself). This should not be needed unless you are trying to support
systems with very old BIOSes. This defaults to the full size of the image.
boot-type=value
Specifies the boot semantics used by the El Torito boot image: If the value
is fd, then the boot image is assumed to be a bootable floppy image. If the
value is hd, then the boot image is assumed to be a bootable hard disk
image. If the value is no-emulation, the boot image is used without floppy
or hard disk emulation. If the boot image is exactly 1.2MB, 1.44MB, or
2.88MB, then the default is fd, otherwise the default is no-emulation.
Format iso9660 - filename and size extensions
Various extensions to the base ISO9660 format.
allow-ldots
If enabled, allows filenames to begin with a leading period. If disabled,
filenames that begin with a leading period will have that period replaced by
an underscore character in the standard ISO9660 namespace. This does not
impact names stored in the Rockridge or Joliet extension area. Default:
disabled.
allow-lowercase
If enabled, allows filenames to contain lowercase characters. If disabled,
filenames will be forced to uppercase. This does not impact names stored in
the Rockridge or Joliet extension area. Default: disabled.
allow-multidot
If enabled, allows filenames to contain multiple period characters, in
violation of the ISO9660 specification. If disabled, additional periods
will be converted to underscore characters. This does not impact names
stored in the Rockridge or Joliet extension area. Default: disabled.
allow-period
If enabled, allows filenames to contain trailing period characters, in
violation of the ISO9660 specification. If disabled, trailing periods will
be converted to underscore characters. This does not impact names stored in
the Rockridge or Joliet extension area. Default: disabled.
allow-pvd-lowercase
If enabled, the Primary Volume Descriptor may contain lowercase ASCII
characters, in violation of the ISO9660 specification. If disabled,
characters will be converted to uppercase ASCII. Default: disabled.
allow-sharp-tilde
If enabled, sharp and tilde characters will be permitted in filenames, in
violation if the ISO9660 specification. If disabled, such characters will
be converted to underscore characters. Default: disabled.
allow-vernum
If enabled, version numbers will be included with files. If disabled,
version numbers will be suppressed, in violation of the ISO9660 standard.
This does not impact names stored in the Rockridge or Joliet extension area.
Default: enabled.
iso-level
This enables support for file size and file name extensions in the core
ISO9660 area. The name extensions specified here do not affect the names
stored in the Rockridge or Joliet extension areas.
iso-level=1
The most compliant form of ISO9660 image. Filenames are limited to
8.3 uppercase format, directory names are limited to 8 uppercase
characters, files are limited to 4 GiB, the complete ISO9660 image
cannot exceed 4 GiB.
iso-level=2
Filenames are limited to 30 uppercase characters with a 30-character
extension, directory names are limited to 30 characters, files are
limited to 4 GiB.
iso-level=3
As with iso-level=2, except that files may exceed 4 GiB.
iso-level=4
As with iso-level=3, except that filenames may be up to 193
characters and may include arbitrary 8-bit characters.
joliet Microsoft's Joliet extensions store a completely separate set of directory
information about each file. In particular, this information includes
Unicode filenames of up to 255 characters. Default: enabled.
limit-depth
If enabled, libarchive will use directory relocation records to ensure that
no pathname exceeds the ISO9660 limit of 8 directory levels. If disabled,
no relocation will occur. Default: enabled.
limit-dirs
If enabled, libarchive will cause an error if there are more than 65536
directories. If disabled, there is no limit on the number of directories.
Default: enabled
pad If enabled, 300 kiB of zero bytes will be appended to the end of the
archive. Default: enabled
relaxed-filenames
If enabled, all 7-bit ASCII characters are permitted in filenames (except
lowercase characters unless allow-lowercase is also specified). This
violates ISO9660 standards. This does not impact names stored in the
Rockridge or Joliet extension area. Default: disabled.
rockridge
The Rockridge extensions store an additional set of POSIX-style file
information with each file, including mtime, atime, ctime, permissions, and
long filenames with arbitrary 8-bit characters. These extensions also
support symbolic links and other POSIX file types. Default: enabled.
Format iso9660 - zisofs support
The zisofs extensions permit each file to be independently compressed using a gzip-
compatible compression. This can provide significant size savings, but requires the
reading system to have support for these extensions. These extensions are disabled
by default.
compression-level=number
The compression level used by the deflate compressor. Ranges from 0 (least
effort) to 9 (most effort). Default: 6
zisofs Synonym for zisofs=direct.
zisofs=direct
Compress each file in the archive. Unlike zisofs=indirect, this is handled
entirely within libarchive and does not require a separate utility. For
best results, libarchive tests each file and will store the file
uncompressed if the compression does not actually save any space. In
particular, files under 2k will never be compressed. Note that boot image
files are never compressed.
zisofs=indirect
Recognizes files that have already been compressed with the mkzftree utility
and sets up the necessary file metadata so that readers will correctly
identify these as zisofs-compressed files.
zisofs-exclude=filename
Specifies a filename that should not be compressed when using zisofs=direct.
This option can be provided multiple times to suppress compression on many
files.
Format mtree
cksum, device, flags, gid, gname, indent, link, md5, mode, nlink, rmd160, sha1,
sha256, sha384, sha512, size, time, uid, uname
Enable a particular keyword in the mtree output. Prefix with an exclamation
mark to disable the corresponding keyword. The default is equivalent to
“device, flags, gid, gname, link, mode, nlink, size, time, type, uid,
uname”.
all Enables all of the above keywords.
use-set
Enables generation of /set lines that specify default values for the
following files and/or directories.
indent XXX needs explanation XXX
Format newc
hdrcharset
The value is used as a character set name that will be used when translating
file names.
Format odc
hdrcharset
The value is used as a character set name that will be used when translating
file names.
Format pwb
hdrcharset
The value is used as a character set name that will be used when translating
file names.
Format pax
hdrcharset
The value is used as a character set name that will be used when translating
file, group and user names. The value is one of “BINARY” or “UTF-8”. With
“BINARY” there is no character conversion, with “UTF-8” names are converted
to UTF-8.
xattrheader
When storing extended attributes, this option configures which headers
should be written. The value is one of “all”, “LIBARCHIVE”, or “SCHILY”. By
default, both “LIBARCHIVE.xattr” and “SCHILY.xattr” headers are written.
Format ustar
hdrcharset
The value is used as a character set name that will be used when translating
file, group and user names.
Format v7tar
hdrcharset
The value is used as a character set name that will be used when translating
file, group and user names.
Format warc
omit-warcinfo
Set to “true” to disable output of the warcinfo record.
Format xar
checksum=type
Use type as file checksum method. Supported values are “none”, “md5”, and
“sha1” (default).
compression=type
Use type as compression method. Supported values are “none”, “bzip2”,
“gzip” (default), “lzma” and “xz”.
compression_level
The value is a decimal integer from 1 to 9 specifying the compression level.
toc-checksum=type
Use type as table of contents checksum method. Supported values are “none”,
“md5” and “sha1” (default).
Format zip
compression
The value is either “store” or “deflate” to indicate how the following
entries should be compressed. Note that this setting is ignored for
directories, symbolic links, and other special entries.
compression-level
The value is interpreted as a decimal integer specifying the compression
level. Values between 0 and 9 are supported. A compression level of 0
switches the compression method to “store”, other values will enable
“deflate” compression with the given level.
encryption
Enable encryption using traditional zip encryption.
encryption=type
Use type as encryption type. Supported values are “zipcrypt” (traditional
zip encryption), “aes128” (WinZip AES-128 encryption) and “aes256” (WinZip
AES-256 encryption).
experimental
This boolean option enables or disables experimental Zip features that may
not be compatible with other Zip implementations.
fakecrc32
This boolean option disables CRC calculations. All CRC fields are set to
zero. It should not be used except for testing purposes.
hdrcharset
The value is used as a character set name that will be used when translating
file names.
zip64 Zip64 extensions provide additional file size information for entries larger
than 4 GiB. They also provide extended file offset and archive size
information when archives exceed 4 GiB. By default, the Zip writer
selectively enables these extensions only as needed. In particular, if the
file size is unknown, the Zip writer will include Zip64 extensions to guard
against the possibility that the file might be larger than 4 GiB.
Setting this boolean option will force the writer to use Zip64 extensions
even for small files that would not otherwise require them. This is
primarily useful for testing.
Disabling this option with !zip64 will force the Zip writer to avoid Zip64
extensions: It will reject files with size greater than 4 GiB, it will
reject any new entries once the total archive size reaches 4 GiB, and it
will not use Zip64 extensions for files with unknown size. In particular,
this can improve compatibility when generating archives where the entry
sizes are not known in advance.
EXAMPLES
The following example creates an archive write handle to create a gzip-compressed ISO9660
format image. The two options here specify that the ISO9660 archive will use kernel.img as
the boot image for El Torito booting, and that the gzip compressor should use the maximum
compression level.
a = archive_write_new();
archive_write_add_filter_gzip(a);
archive_write_set_format_iso9660(a);
archive_write_set_options(a, "boot=kernel.img,compression=9");
archive_write_open_filename(a, filename, blocksize);
ERRORS
More detailed error codes and textual descriptions are available from the archive_errno()
and archive_error_string() functions.
SEE ALSO
tar(1), archive_read_set_options(3), archive_write(3), libarchive(3)
HISTORY
The libarchive library first appeared in FreeBSD 5.3.
AUTHORS
The options support for libarchive was originally implemented by Michihiro NAKAJIMA.