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 . Include the version number, which you can find by running 'tarlz --version'.  File: tarlz.info, Node: Concept index, Prev: Problems, Up: Top Concept index ************* [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: