z/OS V1R9.0 UNIX System Services Command ... - Christian Grothoff

Localization
Usage Note
Exit Values
Portability
command uses the following localization environment variables:
v LANG
v LC_ALL
v LC_CTYPE
v LC_MESSAGES
v NLSPATH
See Appendix F for more information.
command is a built-in shell command.
If you specified –v, possible exit status values are:
0 Successful completion
1 command could not find command-name, or an error occurred
2 Failure due to incorrect command-line argument
If you did not specify –v, possible exit status values are:
126 command found command-name, but failed to invoke it.
127 An error occurred in the command or it could not find command-name.
Otherwise, the exit status of command is the exit status of command-name.
POSIX.2.
Related Information
sh
compress — Lempel-Ziv file compression
Format
Description
compress [–cDdfVv] [–b bits] [file ...]
command
compress compresses each input file using Lempel-Ziv compression techniques. If
you do not specify any input files, compress reads data from standard input (stdin)
and writes the compressed result to standard output (stdout).
The output files have the same names as the input files but with a .Z suffix. For
example, abc is compressed into abc.Z. If the .Z file already exists and you did not
specify the –f option, compress gives an error and asks whether it should overwrite
the existing file.
compress uses the modified Lempel-Ziv algorithm described in A Technique for
High Performance Data Compression, Terry A. Welch, IEEE Computer, vol. 17, no.
6 (June 1984), pp.8-19. compress first replaces common substrings in the file by
9-bit codes starting at 257. After it reaches code 512, compress begins with 10-bit
codes and continues to use more bits until it reaches the limit set by the –b option.
Chapter 2. Shell command descriptions 143