ggzziipp -- Command

GNU utility to compress files
ggzziipp [ -ccddffhhLLrrttvvVV1199 ] [ _f_i_l_e ... ]

The  command ggzziipp  is the  GNU command  that compresses  _f_i_l_e named  on its
command line.  It will only attempt to compress regular files.

Whenever possible, ggzziipp replaces each _f_i_l_e with one that has the suffix .zz,
while  preserving  its  ownership   and  times  of  last  access  and  last
modification.   If the  name of  _f_i_l_e is longer  than 12  characters (which
prevents ggzziipp  from attaching the  suffix .zz), ggzziipp truncates  it and keeps
its original name within the compressed file.

If its command line names no  _f_i_l_e, ggzziipp compresses what it reads from from
the standard input, and writes it to the standard output.

To restore a compressed file, filter it thorugh the command gguunnzziipp.

ggzziipp  uses the  Lempel-Ziv algorithm  to  perform compression.   Under most
circumstances, this  algorithm compresses files  more tightly than  do most
other commonly used techniques,  such as the LZW algorithm, Huffman coding,
or  adaptive Huffman  coding.  The amount  of compression  obtained depends
upon the  size of the input  and the distribution of  common substrings; in
general, it reduces text by 60% to 70%.

ggzziipp always  compresses its input, even if the  compressed file is slightly
larger than the original.  The worst-case  expansion is a few bytes for the
ggzziipp file header, plus five bytes for every 32-kilobyte block.

_C_o_m_m_a_n_d-_L_i_n_e _O_p_t_i_o_n_s
ggzziipp recognizes the following command-line options:

-cc   Write output to standard output,  and do not change the original _f_i_l_e.
     If  the command  line names  more than  one _f_i_l_e,  ggzziipp writes  to the
     standard output  a sequence  of independently compressed  members.  To
     obtain  better compression, concatenate  the _f_i_l_es  before compressing
     them.

-dd   Decompress each _f_i_l_e.

-ff   force compression or decompression, even if _f_i_l_e has multiple links or
     the corresponding file  already exists.  Without this option, and when
     not  running in  the  background, ggzziipp  prompts to  verify whether  it
     should overwrite an existing file.

-hh   Help: display a screenful of information on how to run this program.

-LL   Display the ggzziipp license.

-qq   Suppress all warning messages.

-rr   Recurse: if  a _f_i_l_e is  a directory, compress or  uncompress all files
     within it.

-tt   Test: check the integrity of a compressed file.

-vv   Verbose: display the name and percentage reduction for each _f_i_l_e as it
     is compressed.

-VV   Display the version  of this command, and the options  by which it was
     compiled.

11-99  Regulate  the speed  of compression,  on  a scale  of from  11 to  99. 11
     performs  the  fastest but  most  superficial  compression, whereas  99
     performs  the  slowest  but most  thorough  compression.   -ffaasstt is  a
     synonym  for  -11, whereas  -bbeesstt  is  a synonym  for  -99. The  default
     compression level is -55.

_A_d_v_a_n_c_e_d _U_s_a_g_e
You  can  concatenate  multiple compressed  files.   In  this case,  gguunnzziipp
extracts all members at once.  For example:

    gzip -c file1 > foo.z
    gzip -c file2 >> foo.z
    gunzip -c foo

is equivalent to:

    cat file1 file2

In case  of damage to one  member of a .zz file, other  members can still be
recovered (if the damaged member  is removed).  However, you can get better
compression by compressing all members at once:

    cat file1 file2 | gzip > foo.z

compresses better than:

    gzip -c file1 file2 > foo.z

If you  want to  recompress concatenated  files to get  better compression,
type:

    zcat old.z | gzip > new.z

_E_n_v_i_r_o_n_m_e_n_t
ggzziipp  reads the  environment  variable GGZZIIPP  for its  default options.   It
interprets  these options  first; you  can override  them by  setting other
options on the ggzziipp command line.

_S_e_e _A_l_s_o
ccoommmmaannddss, ccoommpprreessss, gguunnzziipp uunnccoommpprreessss, uunnppaacckk

_D_i_a_g_n_o_s_t_i_c_s
If all went well, ggzziipp returns zero upon exiting.  If an error occurred, it
returns one; if it issued a warning message, it returns two.

ggzziipp can issue the following warning messages:

UUssaaggee: ggzziipp [-ccddffhhLLrrttvvVV1199] [ffiillee ...]
     The  ggzziipp  command  line  contained  an  option  that  ggzziipp  does  not
     recognize.

_f_i_l_e: aallrreeaaddyy hhaass zz ssuuffffiixx -- nnoo cchhaannggee
     _f_i_l_e  already  has the  suffix  .zz; therefore,  ggzziipp  assumes that  it
     already is compressed.

_f_i_l_e nnoott aa rreegguullaarr ffiillee oorr ddiirreeccttoorryy: iiggnnoorreedd
     A _f_i_l_e is  not a regular file or directory.   ggzziipp does not attempt to
     compress devices, pipes, or other special files.

_f_i_l_e  hhaass _X_X ootthheerr lliinnkkss: uunncchhaannggeedd
     _f_i_l_e has  more than one  link.  By default,  ggzziipp does not  compress a
     file that has multiple links.
