NAME

       pmlogcompress, pmlogdecompress - compress and decompress PCP archive files

SYNOPSIS

       pmlogcompress [-NV?]  [-A arg] [-c proglist] [-f prog] [-l limit] [-o type] [-Z min] archive ...
       pmlogdecompress [-NV?]  [-t dir] archive ...

DESCRIPTION

       pmlogcompress  and  pmlogdecompress support the compression and decompression of the files that make up a
       Performance Co-Pilot (PCP) archive; refer to LOGARCHIVE(5) for an explanation of the various  files  that
       are components of a PCP archive.

       The  archive  arguments may be either the name of a single file in a PCP archive or the basename of a PCP
       archive, as in the style generated by pmlogbasename(1).  In the former case, pmlogcompress will  compress
       (or pmlogdecompress will decompress) just that file, but in the latter case pmlogcompress will attempt to
       compress  (or  for  pmlogdecompress  to  decompress)  all  the  files that are part of the associated PCP
       archive.

       For decompression  the  suffix  of  the  name  of  each  file  associated  with  archive  determines  the
       decompression tool to be used.

OPTIONS

       The available command line options are:

       -A arg, --arg=arg
            arg is used as an argument to the compression program; most likely useful with the -f option so that
            the choice of compression program is deterministic.

            The  processing  of  arg is not sophisticated, so embedded shell variables, escape characters, shell
            ``glob'' characters and white space should be avoided.

            Multiple -A options are allowed and all the arg arguments will be used.

       -c proglist, --command=proglist
            Depending on other command line options, and the availability of installed compression programs, the
            choice if program when compressing may vary.  The -c option allows a list of compression programs to
            be provided, either with multiple -c options and/or by separating program names  in  proglist  by  a
            colon, in the style of the shell's $PATH notation.

            The default value for proglist is zstd:xz:bzip2:gzip.

       -f prog, --use=prog
            If  only  one  program  is  to be considered for compression then this may be specified using the -f
            option.  The effect is the same as if only one -c option was used, and  proglist  contained  exactly
            one program name, namely prog.

       -l limit, --lower-limit=limit
            When compressing, do not consider files smaller than limit (bytes).

            The default value for limit is 4096.

       -N, --show-me
            Do nothing, but show what commands would have been executed.

       -o type, --optimize=type
            When  compressing  the  -o option will try to pick the compression program from proglist (see the -c
            option above) that does the ``best'' job, where type may be space to choose the compression  program
            that  produces  the  smallest  output  file, or time to choose the compression program that uses the
            least CPU time.

            If archive is an archive basename then the largest of the files that are part of the associated  PCP
            archive is selected for the test, else archive will be used for the test.

            Use of this option means each of the selected archive files will be compressed multiple times, so it
            is  likely  that  -o  would  be  used in experiments with -N (and possibly -V) to determine the best
            compression tool for the local environment and PCP archives.

       -t dir, --dir=dir
            When decompressing any compressed  files  will  (by  default)  be  replaced  by  their  decompressed
            equivalent.   The -t option changes this behavior to create a duplicate, uncompressed archive in the
            dir directory.

            If archive is a single file, then only that file is decompressed into dir,  but  if  archive  is  an
            archive  basename  then  all of the files of archive will be copied, and possibly decompressed, into
            dir.

            If a file is not compressed, then an attempt will first be made to create a hard link  in  dir  with
            ln(1) and if this fails then a copy is made with cp(1).

            dir must exist before pmlogdecompress is run.

       -V, --verbose
            Increase verbosity.

       -Z min, --min-zstd-size=min
            xz(1)  produces  smaller  compressed  files  for small input files, but at some point the input file
            becomes large enough that zstd(1) produces smaller compressed  files  and  zstd  is  typically  much
            faster.

            When  both xz and xstd are in consideration (see the -c option above), then the -Z option allows the
            user to tune where the xz to zstd cut-over happens; input files smaller than min (in bytes) will  be
            compressed with xz else zstd will be used.

            The default value for min is 52428800 (50MiB).

       -?, --help
            Display usage message and exit.

NOTE

       For  most  users  these tools will not be used directly because explicit compression and decompression of
       PCP archives is not required.

       Rather, if archive compression is enabled, then this  will  be  done  indirectly  from  the  PCP  archive
       managements scripts pmlogger_check(1), pmlogger_daily(1) and pmlogger_rewrite(1).

       Decompression  is  handled  transparently  during  archive  replay  by  the  routines  that implement the
       Performance Metrics Programming Interface (PMAPI).

SEE ALSO

       PCPIntro(1), bzip2(1),  gzip(1),  pmlogbasename(1),  pmlogger(1),  pmlogger_check(1),  pmlogger_daily(1),
       pmlogger_rewrite(1), xz(1), zstd(1), PMAPI(3) and LOGARCHIVE(5).

Performance Co-Pilot                                   PCP                                      PMLOGCOMPRESS(1)