diff options
Diffstat (limited to 'doc/tarlz.info')
| -rw-r--r-- | doc/tarlz.info | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/doc/tarlz.info b/doc/tarlz.info new file mode 100644 index 0000000..140336b --- /dev/null +++ b/doc/tarlz.info @@ -0,0 +1,311 @@ +This is tarlz.info, produced by makeinfo version 4.13+ from tarlz.texi. + +INFO-DIR-SECTION Data Compression +START-INFO-DIR-ENTRY +* Tarlz: (tarlz). Archiver with multimember lzip compression +END-INFO-DIR-ENTRY + + +File: tarlz.info, Node: Top, Next: Introduction, Up: (dir) + +Tarlz Manual +************ + +This manual is for Tarlz (version 0.4, 23 April 2018). + +* Menu: + +* Introduction:: Purpose and features of tarlz +* Invoking tarlz:: Command line interface +* Examples:: A small tutorial with examples +* Problems:: Reporting bugs +* Concept index:: Index of concepts + + + Copyright (C) 2013-2018 Antonio Diaz Diaz. + + This manual is free documentation: you have unlimited permission to +copy, distribute and modify it. + + +File: tarlz.info, Node: Introduction, Next: Invoking tarlz, Prev: Top, Up: Top + +1 Introduction +************** + +Tarlz is a small and simple implementation of the tar archiver. By +default tarlz creates, lists and extracts archives in the 'ustar' format +compressed with lzip on a per file basis. Tarlz can append files to the +end of such compressed archives. + + Each tar member is compressed in its own lzip member, as well as the +end-of-file blocks. This same method works for any tar format (gnu, +ustar, posix) and is fully backward compatible with standard tar tools +like GNU tar, which treat the resulting multimember tar.lz archive like +any other tar.lz archive. + + Tarlz can create tar archives with four levels of compression +granularity; per file, per directory, appendable solid, and solid. + + Tarlz is intended as a showcase project for the maintainers of real +tar programs to evaluate the format and perhaps implement it in their +tools. + + The diagram below shows the correspondence between tar members +(formed by a header plus optional data) in the tar archive and lzip +members in the resulting multimember tar.lz archive: *Note File format: +(lzip)File format. + +tar ++========+======+========+======+========+======+========+ +| header | data | header | data | header | data | eof | ++========+======+========+======+========+======+========+ + +tar.lz ++===============+===============+===============+========+ +| member | member | member | member | ++===============+===============+===============+========+ + +Of course, compressing each file (or each directory) individually is +less efficient than compressing the whole tar archive, but it has the +following advantages: + + * The resulting multimember tar.lz archive can be decompressed in + parallel with plzip, multiplying the decompression speed. + + * New members can be appended to the archive (by removing the eof + member) just like to an uncompressed tar archive. + + * It is a safe posix-style backup format. In case of corruption, + tarlz can extract all the undamaged members from the tar.lz + archive, skipping over the damaged members, just like the standard + (uncompressed) tar. Moreover, lziprecover can be used to recover at + least part of the contents of the damaged members. + + * A multimember tar.lz archive is usually smaller than the + corresponding solidly compressed tar.gz archive, except when + individually compressing files smaller than about 32 KiB. + + +File: tarlz.info, Node: Invoking tarlz, Next: Examples, Prev: Introduction, Up: Top + +2 Invoking tarlz +**************** + +The format for running tarlz is: + + tarlz [OPTIONS] [FILES] + +On archive creation or appending, tarlz removes leading and trailing +slashes from file names, as well as file name prefixes containing a +'..' component. On extraction, archive members containing a '..' +component are skipped. + + tarlz supports the following options: + +'-h' +'--help' + Print an informative help message describing the options and exit. + +'-V' +'--version' + Print the version number of tarlz on the standard output and exit. + +'-c' +'--create' + Create a new archive. + +'-C DIR' +'--directory=DIR' + Change to directory DIR. When creating or appending, the position + of each '-C' option in the command line is significant; it will + change the current working directory for the following FILES until + a new '-C' option appears in the command line. When extracting, all + the '-C' options are executed in sequence before starting the + extraction. Listing ignores any '-C' options specified. DIR is + relative to the then current working directory, perhaps changed by + a previous '-C' option. + +'-f ARCHIVE' +'--file=ARCHIVE' + Use archive file ARCHIVE. '-' used as an ARCHIVE argument reads + from standard input or writes to standard output. + +'-q' +'--quiet' + Quiet operation. Suppress all messages. + +'-r' +'--append' + Append files to the end of an archive. The archive must be a + regular (seekable) file compressed as a multimember lzip file, and + the two end-of-file blocks plus any zero padding must be contained + in the last lzip member of the archive. First this last member is + removed, then the new members are appended, and then a new + end-of-file member is appended to the archive. Exit with status 0 + without modifying the archive if no FILES have been specified. + tarlz can't append files to an uncompressed tar archive. + +'-t' +'--list' + List the contents of an archive. + +'-v' +'--verbose' + Verbosely list files processed. + +'-x' +'--extract' + Extract files from an archive. + +'-0 .. -9' + Set the compression level. The default compression level is '-6'. + +'--asolid' + When creating or appending to a compressed archive, use appendable + solid compression. All the files being added to the archive are + compressed into a single lzip member, but the end-of-file blocks + are compressed into a separate lzip member. This creates a solidly + compressed appendable archive. + +'--dsolid' + When creating or appending to a compressed archive, use solid + compression for each directory especified in the command line. The + end-of-file blocks are compressed into a separate lzip member. This + creates a compressed appendable archive with a separate lzip + member for each top-level directory. + +'--solid' + When creating or appending to a compressed archive, use solid + compression. The files being added to the archive, along with the + end-of-file blocks, are compressed into a single lzip member. The + resulting archive is not appendable. No more files can be later + appended to the archive without decompressing it first. + +'--group=GROUP' + When creating or appending, use GROUP for files added to the + archive. If GROUP is not a valid group name, it is decoded as a + decimal numeric group ID. + +'--owner=OWNER' + When creating or appending, use OWNER for files added to the + archive. If OWNER is not a valid user name, it is decoded as a + decimal numeric user ID. + +'--uncompressed' + With '--create', don't compress the created tar archive. Create an + uncompressed tar archive instead. + + + Exit status: 0 for a normal exit, 1 for environmental problems (file +not found, invalid flags, I/O errors, etc), 2 to indicate a corrupt or +invalid input file, 3 for an internal consistency error (eg, bug) which +caused tarlz to panic. + + +File: tarlz.info, Node: Examples, Next: Problems, Prev: Invoking tarlz, Up: Top + +3 A small tutorial with examples +******************************** + +Example 1: Create a multimember compressed archive 'archive.tar.lz' +containing files 'a', 'b' and 'c'. + + tarlz -cf archive.tar.lz a b c + + +Example 2: Append files 'd' and 'e' to the multimember compressed +archive 'archive.tar.lz'. + + tarlz -rf archive.tar.lz d e + + +Example 3: Create a solidly compressed appendable archive +'archive.tar.lz' containing files 'a', 'b' and 'c'. Then append files +'d' and 'e' to the archive. + + tarlz --asolid -cf archive.tar.lz a b c + tarlz --asolid -rf archive.tar.lz d e + + +Example 4: Create a compressed appendable archive containing directories +'dir1', 'dir2' and 'dir3' with a separate lzip member per directory. +Then append files 'a', 'b', 'c', 'd' and 'e' to the archive, all of +them contained in a single lzip member. The resulting archive +'archive.tar.lz' contains 5 lzip members (including the eof member). + + tarlz --dsolid -cf archive.tar.lz dir1 dir2 dir3 + tarlz --asolid -rf archive.tar.lz a b c d e + + +Example 5: Create a solidly compressed archive 'archive.tar.lz' +containing files 'a', 'b' and 'c'. Note that no more files can be later +appended to the archive without decompressing it first. + + tarlz --solid -cf archive.tar.lz a b c + + +Example 6: Extract all files from archive 'archive.tar.lz'. + + tarlz -xf archive.tar.lz + + +Example 7: Extract files 'a' and 'c' from archive 'archive.tar.lz'. + + tarlz -xf archive.tar.lz a c + + +Example 8: Copy the contents of directory 'sourcedir' to the directory +'targetdir'. + + tarlz -C sourcedir -c . | tarlz -C targetdir -x + + +File: tarlz.info, Node: Problems, Next: Concept index, Prev: Examples, Up: Top + +4 Reporting bugs +**************** + +There are probably bugs in tarlz. There are certainly errors and +omissions in this manual. If you report them, they will get fixed. If +you don't, no one will ever know about them and they will remain unfixed +for all eternity, if not longer. + + If you find a bug in tarlz, please send electronic mail to +<lzip-bug@nongnu.org>. Include the version number, which you can find +by running 'tarlz --version'. + + +File: tarlz.info, Node: Concept index, Prev: Problems, Up: Top + +Concept index +************* + + +* Menu: + +* bugs: Problems. (line 6) +* examples: Examples. (line 6) +* getting help: Problems. (line 6) +* introduction: Introduction. (line 6) +* invoking: Invoking tarlz. (line 6) +* options: Invoking tarlz. (line 6) +* usage: Invoking tarlz. (line 6) +* version: Invoking tarlz. (line 6) + + + +Tag Table: +Node: Top223 +Node: Introduction785 +Node: Invoking tarlz3280 +Node: Examples7278 +Node: Problems8975 +Node: Concept index9501 + +End Tag Table + + +Local Variables: +coding: iso-8859-15 +End: |