• Last 5 Forum Topics
    Last post

The Web Only This Site



  • MARC

    Mailing list ARChives
    - Search by -


    Computing Dictionary

  • Text Link Ads

  • LINUX man pages
  • Linux Man Page Viewer

    The following form allows you to view linux man pages.





           compress [ -f ] [ -v ] [ -c ] [ -V ] [ -r ] [ -b bits ] [ name ...  ]
           uncompress [ -f ] [ -v ] [ -c ] [ -V ] [ name ...  ]
           zcat [ -V ] [ name ...  ]


           Compress  reduces the size of the named files using adaptive Lempel-Ziv
           coding.  Whenever possible, each file  is  replaced  by  one  with  the
           extension  .Z, while keeping the same ownership modes, access and modi-
           fication times.  If no files are specified, the standard input is  com-
           pressed to the standard output.  Compress will only attempt to compress
           regular files.  In particular, it will ignore symbolic links. If a file
           has multiple hard links, compress will refuse to compress it unless the
           -f flag is given.
           If -f is not given and compress is run in the foreground, the  user  is
           prompted as to whether an existing file should be overwritten.
           Compressed  files  can  be restored to their original form using uncom-
           press or zcat.
           uncompress takes a list of files on its command line and replaces  each
           file  whose  name  ends with .Z and which begins with the correct magic
           number with an uncompressed file without the .Z.  The uncompressed file
           will have the mode, ownership and timestamps of the compressed file.
           The  -c  option makes compress/uncompress write to the standard output;
           no files are changed.
           zcat is identical to uncompress -c.  zcat uncompresses either a list of
           files  on  the command line or its standard input and writes the uncom-
           pressed data on standard output.  zcat will uncompress files that  have
           the correct magic number whether they have a .Z suffix or not.
           If  the -r flag is specified, compress will operate recursively. If any
           of the file names specified on the command line are  directories,  com-
           press  will  descend  into  the directory and compress all the files it
           finds there.
           The -V flag tells each of these  programs  to  print  its  version  and
           patchlevel, along with any preprocessor flags specified during compila-
           tion, on stderr before doing any compression or uncompression.
           Compress uses the modified Lempel-Ziv algorithm popularized in "A Tech-
           nique for High Performance Data Compression", Terry A. Welch, IEEE Com-
           puter, vol. 17, no. 6 (June 1984), pp. 8-19.  Common substrings in  the
           file  are  first  replaced by 9-bit codes 257 and up.  When code 512 is
           reached, the algorithm switches to 10-bit codes and  continues  to  use
           more  bits until the limit specified by the -b flag is reached (default
           16).  Bits must be between 9 and 16.  The default can be changed in the
           source to allow compress to be run on a smaller machine.
           Compression is generally much better than that achieved by Huffman cod-
           ing (as used in pack), or adaptive Huffman coding (compact), and  takes
           less time to compute.
           Under  the  -v  option, a message is printed yielding the percentage of
           reduction for each file compressed.
           Exit status is normally 0; if the last file is larger after (attempted)
           compression, the status is 2; if an error occurs, exit status is 1.


           pack(1), compact(1)


           Usage: compress [-dfvcVr] [-b maxbits] [file ...]
                   Invalid options were specified on the command line.
           Missing maxbits
                   Maxbits must follow -b.
           file: not in compressed format
                   The file specified to uncompress has not been compressed.
           file: compressed with xx bits, can only handle yy bits
                   File was compressed by a program that could deal with more bits
                   than the compress code on this machine.   Recompress  the  file
                   with smaller bits.
           file: already has .Z suffix -- no change
                   The  file is assumed to be already compressed.  Rename the file
                   and try again.
           file: filename too long to tack on .Z
                   The file cannot be compressed because its name is  longer  than
                   12  characters.   Rename  and try again.  This message does not
                   occur on BSD systems.
           file already exists; do you wish to overwrite (y or n)?
                   Respond "y" if you want the output file to be replaced; "n"  if
           uncompress: corrupt input
                   A  SIGSEGV  violation was detected which usually means that the
                   input file has been corrupted.
           Compression: xx.xx%
                   Percentage of the input saved by compression.   (Relevant  only
                   for -v.)
           -- not a regular file or directory: ignored
                   When the input file is not a regular file or directory, (e.g. a
                   symbolic link, socket, FIFO, device file),  it  is  left  unal-
           -- has xx other links: unchanged
                   The  input file has links; it is left unchanged.  See ln(1) for
                   more information. Use the -f flag to force compression of  mul-
                   tiply-linked files.
           -- file unchanged
                   No  savings is achieved by compression.  The input remains vir-
                                         local                         COMPRESS(1)

  • Linux

    The Distributions


    The Software


    The News


  • Toll Free
Copyright © 1999 - 2016 by LinuxGuruz