From: Bertram Scharpf <lists@...>
Date: 2007-04-20T17:12:06+09:00
Subject: Process name and $0

Hi,

the following might be Linux specific.

Running Irb and having a look into the process table looks
like this:

  $ ps aux | grep [i]rb
  user     30546  1.3  1.0   7880  5328 pts/3    S+   09:49   0:00 irb
  $ ps -A | grep irb
  30546 pts/3    00:00:00 irb
  $ pgrep irb
  30546
  $ ruby -pe 'sub "\0", "\n"' /proc/30546/cmdline
  irb
  $ cat /proc/30546/stat
  30546 (irb) S ...

  $ cat /etc/gentoo-release
  Gentoo Base System release 1.12.9

Now, I'm running a daemon written in Ruby that I want to
appear under its own name rather than "ruby" in ps, pstree,
top and so forth.

Having a look at Irb's source code and at
`rb_define_hooked_variable()' in `ruby.c' shows me that
setting $0 does at least partially what I want. It works for
the 'ps -A' call and for the 'cmdline' output. 'pgrep' still
doesn't respond and 'stat' still contains "ruby".

I cannot find it: How does Irb manage to change the process
name in its higher sense?

Thanks for any hints in advance.

Bertram


-- 
Bertram Scharpf
Stuttgart, Deutschland/Germany
http://www.bertram-scharpf.de