Check number of running scripts using ps

Question

I\'m writing a script (show_volume.sh) which may be called several times in short intervals. I need a way to determine whether there is more than just one running instance o

Answer 1

At the moment ps runs a process grep show_volume.sh is also running, so you always count the grep!

Simple solution, grep s[h]ow_volume.sh. The grep (not shell) will collapse the [h] to h and search for what you want, but your grep won't match itself because it will have [] in the parameter.

pgrep is also useful for this task and is smart enough to always exclude itself.

Answer 2

If you're running the script as different users then ps -a will only show instances for the current user and only those with an attached terminal. Use ps -ax or ps -e.

pgrep -c

will show a count without having to use wc.

Answer 3

The solution provided by ajreal:

ps -a | grep show_volume.sh | grep -v grep | wc -l

should work. If it does not, please provide output of

ps -a | grep show_volume.sh | grep -v grep

here

Answer 4

Try to exclude grep as well, as your grep itself also contains show_volume.sh, an example

ps -a | grep show_volume.sh | grep -v grep | wc -l