Shell Programming and Scripting

Solved Stupidly I didn't put brackets around the , thanks for all the help guys
if ps ax | grep Cluster__check.bash | grep -v grep > /dev/null -- fails
(if ps ax | grep Cluster__check.bash | grep -v grep > /dev/null) --works

It might look like it works, but it doesn't

Bash if doesn't work as such. The if gets help from the test program. To make it look more in line with other programing language syntax, the test command has an alias, `[' (open square bracket ), followed by a close bracket `]'. That's why you don't see the test word written all that often.

Your statement should have been

Code:

if [ -n `ps ax | grep Cluster__check.bash | grep -v grep > /dev/null` ]; then
    # do something
fi

Or something similar to it.

No I think he is wanting to test the return code of the final grep command
I'd be more inclined to do:

Code:

ps ax | grep -q '[C]luster__check.bash'
if [ $? -eq 0 ]; then
    # it's still running
fi

Thanks thats how I finally got it to work I should have posted the working script up rather than deleting it, I'll put it back up tomorrow.

Cheers