Linux – find command from PID

The problem with /proc/PID/exe is that, for shell scripts, it shows the location of the shell. The problem with /proc/PID/cwd is that is shows the current working directory of the process. If the process changes directories, that is reflected in the target of that symlink.

This will show what the $PWD was at the time the script was started (substitute the process ID you're interested in where you see "PID"):

procdir=$(grep -az "\bPWD" /proc/PID/environ); echo $procdir

or simply:

grep -az "\bPWD" /proc/PID/environ

This will show the command that started it so you can see if a relative or absolute directory was used:

proccmd=$(grep -az PROC_NAME /proc/PID/cmdline); echo $proccmd

or simply:

grep -az PROC_NAME /proc/PID/cmdline

Together, these should show you which script is being run. For one started with ./ all you need is procdir.

You can find more documentation about the /proc/[pid]/sched file in this article:

http://lwn.net/Articles/242900/

Look at the comments. Most of the fields are explained.

Addendum: the file is writeable to reset the statistics.