GNU.WIKI: The GNU/Linux Knowledge Base

  [HOME] [PHP Manual] [HowTo] [ABS] [MAN1] [MAN2] [MAN3] [MAN4] [MAN5] [MAN6] [MAN7] [MAN8] [MAN9]

  [0-9] [Aa] [Bb] [Cc] [Dd] [Ee] [Ff] [Gg] [Hh] [Ii] [Jj] [Kk] [Ll] [Mm] [Nn] [Oo] [Pp] [Qq] [Rr] [Ss] [Tt] [Uu] [Vv] [Ww] [Xx] [Yy] [Zz]


NAME

       zp - ZPAQ open standard maximum compressor with prebuilt compression
       levels

SYNOPSIS

         create : zp cN archive.zpaq file [file ...]
         append : zp aN archive.zpaq file [file ...]
         list   : zp l archive.zpaq
         extract: zp [ex][N] archive.zpaq

DESCRIPTION

   General
       PAQ family was a series of open source data compression archivers that
       have evolved through collaborative development to top rankings on
       several benchmarks measuring compression ratio although at the expense
       of speed and memory usage.

       ZPAQ ia a proposed standard format for highly compressed data that
       allows new compression algorithms to be developed without breaking
       compatibility with older programs. Zp is based on PAQ-like context
       mixing algorithms which are top ranked on many benchmarks. The format
       supports archivers, single file compressors, and memory to memory
       compression.

       Zp's goal is a high compression ratio in an open format without loss of
       compatibility between versions as advanced compression techniques are
       discovered.

       If you compress in Windows and extract in Linux, then the program will
       change "\" to "/" during extraction and vice versa. Slashes can be
       stored with either convention. The program guesses the operating system
       by counting "/" and "\" in the PATH environment variable. If this
       heuristic fails (PATH not defined) then no slash translation is done.

       Paths must be relative to the current directory. The program will warn
       if you store an absolute path. You can only extract such files with
       command e or by overriding the filename.

           zp c archive.zpaq  /dir/file  (Warning: starts with "/")
           zp x archive.zpaq             (Error: bad filename)
           zp e archive.zpaq             (OK: extracts file1 to current directory)
           zp x archive.zpaq  newfile    (OK: extracts newfile to current directory)
           zp x archive.zpaq  /dir/file  (OK: creates /dir if needed)

       Also, the same rule applies to file names containing control
       characters, or longer than 511 characters, or that start with a drive
       letter like "C:" or contain relative ".." paths.

       If this program is run in Linux or UNIX or compiled with g++ in Windows
       then it will interpret wildcards on the command line in the usual way.
       A * matches any string and ? matches any character.

           zp c archive.zpaq  *

       will compress all files in the current directory to "archive.zpaq".
       However, it will not recurse directories. You need to specify the files
       in each directory that you want to add.

       The program does not save file timestamps or permissions like some
       other archivers do. Extracted files are dated from the time of
       extraction with default permissions. If you need these capabilities,
       then create a tar file and compress that instead.

       The compression option 1, 2, or 3 means compress fast, medium, or best
       respectively. Better compression requires more time and memory.
       Decompression speed and memory are the same as for compression. Speed
       (T3200, 2.0 GHz) and memory usage are as follows. The following table
       shows comparison to "zip -9" compression All modes compress better but
       slower than zip.

                       Memory     Speed     Calgary corpus
                       ------  -----------  ---------------
           1 (fast)     38 MB  0.7  sec/MB    807,214 bytes
           2 (default) 111 MB  2.3  sec/MB    699,586 bytes
           3 (small)   246 MB  6.4  sec/MB    644,545 bytes
           zip -9       <1 MB  0.13 sec/MB  1,020,719 bytes

       zp(1) uses compiled ZPAQL (generated by "zpaq oc") to compress and
       extract in each of the 3 modes about twice as fast as using interpreted
       code. It automatically recognizes these configurations even if they are
       produced by other programs. The default compression is the same as the
       default produced by zpaq(1) and zpipe(1). If another program produces a
       different configuration, then this program will still correctly
       decompress it by interpreting the code, which is slower. Also, zpaq(1),
       unzpaq(1), and zpipe(1) can decompress archives produced by this
       program.

       The program stores a filename, comment, and SHA-1 checksum for each
       file. Other programs may omit these, but this program will still be
       able to decompress them. This program follows the convention that if
       the name is omitted, then the contents should be appended to the
       previous file. If the first filename is omitted, then you must supply
       it on the command line during extraction. Each filename on the command
       line replaces one named file in the archive.

       head2 Commands

       a[N]
           Append to archive.

           Value N regulates the speed of compression using the specified
           digit: 1 (fast, less compression), 2 (medium, default), 3 (best,
           highest compression).

       c[N]
           Create archive.

           Value N regulates the speed of compression using the specified
           digit: 1 (fast, less compression), 2 (medium, default), 3 (best,
           highest compression).

       e[N]
           Extract to current directory.

           With N, extract only block N (1, 2, 3...), where 1 is the first
           block.  Otherwise all blocks are extracted. The l command shows
           which files are in each block.

       l   List contents of archive.

       x[N]
           Extract with full path names (files... overrides stored names).

           With N, extract only block N (1, 2, 3...), where 1 is the first
           block.  Otherwise all blocks are extracted. The l command shows
           which files are in each block.

OPTIONS

       None.

EXAMPLES

   Create
       The archive name must end with .zpaq. All commands will add the
       extension automatically if you don't specify it.

       To create an archive:

           zp c3 archive.zpaq files ...

       File names are stored in the archive as they appear on the command
       line. If you specify a path to a different directory, the path is
       stored, and created during extraction. The e command extracts to the
       current directory.

   Append
       To (a)ppend to an existing archive. If the archive does not exist then
       it is created as with the c command. The files are grouped into blocks
       (solid archive) for each command (see l command).

           zp a3 archive.zpaq files ...

   List
       To list the contents of an archive. Files are listed in the same block
       order they were added:

           zp l archive.zpaq

   Extract
       To extract the contents of the archive:

           zp x archive.zpaq

       To extract specific block (see l command output):

           zp x1 archive.zpaq

       Blocks are "solid" which means you cannot extract files within a block
       without extracting the earlier files. To extract first file in block
       under another name:

           zp x1 archive.zpaq other-name

       Program will not overwrite existing files during extraction unless you
       specify the filenames on the command line:

           zp x archive.zpaq               (Error: file1 exists)
           zp x archive.zpaq file1 file2   (Overwrite file1, file2)

ENVIRONMENT

       PATH is checked for detecting if slash conversions are required. An
       empty value will disable conversions.

FILES

       None.

STANDARDS

       See zpaq*.pdf (ZPAQ Level 1 and later) in section AVAILABILITY. It is
       anticipated that future levels (ZPAQ-2, ZPAQ-3, etc.) will be backward
       compatible, such that newer levels can read archives produced by older
       programs.

AVAILABILITY

       http://mattmahoney.net/dc

SEE ALSO

       bzip2(1) gzip(1) lzma(1) lzop(1) p7zip(1) rzip(1) unace(1) unrar(1)
       unzip(1) zip(1) zpaq(1)

AUTHORS

       Program was written by Matt Mahoney <matmahoney@yahoo.com>

       This manual page was written by Jari Aalto <jari.aalto@cante.net>.
       Released under license GNU GPL version 3 or (at your option) any later
       version. For more information about license, visit
       <http://www.gnu.org/copyleft/gpl.php>.



  All copyrights belong to their respective owners. Other content (c) 2014-2018, GNU.WIKI. Please report site errors to webmaster@gnu.wiki.
Page load time: 0.092 seconds. Last modified: November 04 2018 12:49:43.