pack(1)                                                         pack(1)

  pack

  NAME

    pack - compress files

  SYNOPSIS

    pack [-f] [-] file ...

  DESCRIPTION

    The pack(1) utility compresses one or more specified files, and stores the
    compressed versions in files identified by the name file.z. The specified
    file can include the .z suffix. If the calling process has the appropriate
    privileges, the original file is removed. To restore a packed file, use
    unpack(1) or pcat(1).

    For each packed file, pack(1) writes to standard output one of the lines:

    pack: file: percent% Compression
    or
    pack: file: no saving - file unchanged

    where file is the file name and percent is the percent compression.

    A file will not be packed if:
    *     It appears to already be packed.
    *     It has links.
    *     It is a directory.
    *     It cannot be opened.
    *     It is empty.
    *     The packed file will not be smaller than the original.
    *     Adding the .z extension would make the file name more than
          {NAME_MAX} bytes long.
    *     The file file.z already exists.
    *     The .z file cannot be created.
    *     An input/output (I/O) error occurred during processor.

    The pack(1) utility takes the following options:

    -f
        Force packing of files.

    -
        If one of the operands is -, pack(1) writes to standard output the
        number of times each byte is used, its relative frequency, and the
        code for that byte. Subsequent uses of - instead of file on the
        command line turn this feature off and on.

  DIAGNOSTICS

    The pack(1) utility exits with a status of 0 for success and >0 if an
    error occurred.

  NOTES

    Traditional implementations of pack(1) use Huffman encoding. This
    implementation is a link to the gzip(1) program, and uses the compression
    algorithms available to gzip(1).

  SEE ALSO

    pcat(1)

    unpack(1)