NAME
xar - eXtensible ARchiver
SYNOPSIS
xar -[ctx][v] ...
DESCRIPTION
The XAR project aims to provide an easily extensible archive format.
Important design decisions include an easily extensible XML table of
contents (TOC) for random access to archived files, storing the TOC at
the beginning of the archive to allow for efficient handling of
streamed archives, the ability to handle files of arbitrarily large
sizes, the ability to choose independent encodings for individual files
in the archive, the ability to store checksums for individual files in
both compressed and uncompressed form, and the ability to query the
table of content’s rich meta-data.
FUNCTIONS
One of the following options must be used:
-c Creates an archive
-t Lists the contents of an archive
-x Extracts an archive
NOTE: all of the above require the use of the -f option (filename) as
this release of xar doesn’t correctly handle pipes or sockets.
-f The filename to use for creation, listing or extraction. With
extraction, this can be a POSIX regular expression.
OPTIONS
--compression
Specifies the compression type to use. Valid values: none,
gzip, bzip2. Default value: gzip
--dump-toc=<filename>
Has xar dump the xml header into the specified file. "-" can be
specified to mean stdout.
--dump-header
Has xar print out the xar binary header information to stdout.
--list-subdocs
List the subdocuments in the xml header
--toc-cksum
Specifies the hashing algorithm to use for xml header
verification. Valid values: none, sha1, and md5. Default
value: sha1
-l On archival, stay on the local device.
-P On extract, set ownership based on uid/gid.
-p On extract, set ownership based on symbolic names, if possible.
-s <filename>
On extract, specifies the file to extract subdocuments to. On
archival, specifies an xml file to add as a subdocument.
-v Verbose output
--exclude
Specifies a POSIX regular expression of files to exclude from
adding to the archive during creation or from being extracted
during extraction. This option can be specified multiple times.
--rsize
Specifies a size (in bytes) for the internal libxar read buffer
while performing I/O.
--coalesce-heap
When multiple files in the archive are identical, only store one
copy of the data in the heap. This creates smaller archives,
but the archives created are not streamable.
--link-same
When the data section of multiple files are identical, hardlink
them within the archive.
--no-compress
Specifies a POSIX regular expression of files to archive, but
not compress. The archived files will be copied raw into the
archive. This can be used to exclude already gzipped files from
being gzipped during the archival process.
EXAMPLES
xar -cf sample.xar /home/uid
Create a xar archive of all files in /home/uid
xar -tf sample.xar
List the contents of the xar archive sample.xar
xar -xf sample.xar
Extract the contents of sample.xar to the current working
directory
BUGS
Doesn’t currently work with pipes or streams. Might be fixed in a
future release.
Probably one or two more somewhere in there. If you find one please
report it to http://code.google.com/p/xar/
AUTHORS
Rob Braun <bbraun AT synack DOT net>
Landon Fuller <landonf AT bikemonkey DOT org>
David Leimbach
Kevin Van Vechten