perf trace/scripting: List available scripts

perf trace/scripting: List available scripts

Lists the available perf trace scripts, one per line e.g.:

root@tropicana:~# perf trace -l
List of available trace scripts:
  workqueue-stats                      workqueue stats (ins/exe/create/destroy)
  wakeup-latency                       system-wide min/max/avg wakeup latency
  rw-by-file <comm>                    r/w activity for a program, by file
  check-perf-trace                     useless but exhaustive test script
  rw-by-pid                            system-wide r/w activity

To be consistent with the other listing options in perf, the
current latency trace option was changed to '-L', and '-l' is
now used to access the script listing as:

To create the list, it searches each scripts/*/bin directory for
files ending with "-report" and reads information found in
certain comment lines contained in those shell scripts:

  - if the comment line starts with "description:", the rest of the
    line is used as a 'half-line' description.  To keep each line in
    the list to a single line, the description should be limited to 40
    characters (the rest of the line contains the script name and
    args)

  - if the comment line starts with "args:", the rest of the line
    names the args the script supports.  Required args should be
    surrounded by <> brackets, optional args by [] brackets.

The current scripts in scripts/perl/bin have also been updated
with description: and args: comments.

Signed-off-by: Tom Zanussi <tzanussi@gmail.com>
Cc: fweisbec@gmail.com
Cc: rostedt@goodmis.org
LKML-Reference: <1260867220-15699-5-git-send-email-tzanussi@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>