Wait for an already launched program to stop before starting a new command.

while (ps -ef | grep [r]unning_program_name); do sleep 10; done; command_to_execute

The '[r]' is to avoid grep from grepping itself. (interchange 'r' by the appropriate letter) Here is an example that I use a lot (as root or halt will not work): while (ps -ef | grep [w]get); do sleep 10; done; sleep 60; halt I add the 'sleep 60' command just in case something went wrong; so that I have time to cancel. Very useful if you are going to bed while downloading something and do not want your computer running all night.

-2

By: m_a_xim

2010-01-14 16:26:34

grep ps sleep automation while process ps wait halt

2 Alternatives + Submit Alt

Wait for an already launched program to stop before starting a new command.

Referring to the original post, if you are using $! then that means the process is a child of the current shell, so you can just use `wait $!`. If you are trying to wait for a process created outside of the current shell, then the loop on `kill -0 $PID` is good; although, you can't get the exit status of the process.
This is sample output - yours may be different.
3

wait $!

noahspurrier · 2010-06-07 21:56:36 5
Wait for an already launched program to stop before starting a new command.

If you really _must_ use a loop, this is better than parsing the output of 'ps': PID=$! ;while kill -0 $PID &>/dev/null; do sleep 1; done kill -0 $PID returns 0 if the process still exists; otherwise 1
This is sample output - yours may be different.
0

wait

bhepple · 2010-01-15 04:03:11 6

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What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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