Re: Basic ps Tips

Lawrence D'Oliveiro <ldo@nz.invalid> wrote:

On Sat, 27 Jul 2024 00:40:49 -0000 (UTC), I wrote:
 

Another useful command to use with ps is pgrep(1)
<https://man7.org/linux/man-pages/man1/pgrep.1.html> 

 
If you are expecting more than one process to match your criteria, it
is easy enough to use the ???-d,??? option to comma-separate them. Then the
output becomes acceptable to the ???-p??? option in ps, e.g.
 
    ps -p$(pgrep -d, bash) -wwo pid,ppid,lstart,tty,etime,cmd
 
to report all the bash sessions I have running (quite a lot). The ???ww???
says not to truncate the output, which is handy for long command lines.

 
Or just use ps -C <command>:

ps -p$(pgrep -d, bash) -wwo pid,ppid,lstart,tty,etime,cmd
  PID  PPID                  STARTED TT           ELAPSED CMD
 1332  1327 Thu Jul 18 10:12:28 2024 pts/1    14-10:02:20 bash
 2019  2018 Thu Jul 18 20:20:31 2024 pts/3    13-23:54:17 bash
 2237  2236 Thu Jul 18 20:39:49 2024 pts/4    13-23:34:59 bash
10821 10820 Sat Jul 20 14:45:57 2024 pts/6    12-05:28:51 bash
20342 20341 Wed Jul 31 09:58:54 2024 pts/7     1-10:15:54 bash

ps -C bash -wwo pid,ppid,lstart,tty,etime,cmd
  PID  PPID                  STARTED TT           ELAPSED CMD
 1332  1327 Thu Jul 18 10:12:28 2024 pts/1    14-10:02:35 bash
 2019  2018 Thu Jul 18 20:20:31 2024 pts/3    13-23:54:32 bash
 2237  2236 Thu Jul 18 20:39:49 2024 pts/4    13-23:35:14 bash
10821 10820 Sat Jul 20 14:45:57 2024 pts/6    12-05:29:06 bash
20342 20341 Wed Jul 31 09:58:54 2024 pts/7     1-10:16:09 bash

Does noone know about -C? I keep seeing things like 'ps -ef | grep
<something> in scripts to see if <something is running, rather than
using 'ps -C'.

Jerry