Really clueless on scripts. Goal: run the command line callCode:#!/bin/bash if grep -q Safari.app `pa ax`; then echo found else echo not found fi
pa ax
which'll give all the running processes, then grep for "Safari.app" in it and do something if found. Any ideas? Thanks.
Try
pa ax | grep -q Safari.app
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
(Oops, first, correction of me: it's 'ps ax' not 'pa ax')
Hi, thanks for the suggestion. That works on the command line, but I don't know how it should be used in a script. I tried:
which seemingly worked (output found when Safari was running), but then I changed 'Safari.app' to 'SafaXXri.app' and it still said found. Any suggestions? Thanks.Code:#!/bin/bash if ps ax | grep -q Safari.app; then echo found else echo not found fi
Oh, I've worked out why. On the command line this
ps ax | grep Safari.app
outputs
54882 ?? S 39:17.90 /Applications/Safari.app/Contents/MacOS/Safari -psn_0_24999894
58634 s001 R+ 0:00.00 grep Safari.app
two positive hits, two lines, one of which is the grep itself! So
ps ax | grep SafXari.app
on the command line outputs
58632 s001 S+ 0:00.00 grep SafXari.app
So it doesn't matter what you put there, it's always going to find one posative hit at least. So the problem isn't the way I've used the line in the script.
So I suppose the question is, and it's probably quite a simple answer, how to filter out
58632 s001 S+ 0:00.00 grep SafXari.app
like lines from the grep output?
Thanks.
Use a different tool perhaps?
pgrep knows to exclude itself.Code:$ ps ax | grep firefox 2305 ? Sl 1:43 /usr/lib/firefox/firefox 3725 pts/4 S+ 0:00 grep --color=auto firefox $ pgrep firefox 2305
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Tried that but my command line hasn't got that command/tool.
Maybe
Code:$ ps ax | awk '$5 ~ /firefox/' 2305 ? Sl 17:58 /usr/lib/firefox/firefox
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
OK, thanks, but that doesn't work in the if situation! I looked in awk's manual page, having looked in grep's manual page to see what q meant, but couldn't see a quiet / silent option for awk. How to use awk in that if line?
Or, how to assign the output of ps ax to a variable, then grep that variable, like what I'm trying to do here but what isn't working at all?:
Code:#!/bin/bash var = ps ax if var | grep -q Safari.app; then echo found else echo not found fi
You can then writeCode:$ var=$(ps ax) $ echo $var | grep -q firefox $ echo $? 0 $ echo $var | grep -q zarniwoop $ echo $? 1
Code:if [ $? -eq 0 ]; then else fi
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
outputs:Code:var=$(ps ax) echo $var | grep -q safari echo $? if [ $? -eq 0 ]; then echo found else echo not found fi
1
found
Then putting safaXXri for the search, it still outputs:
1
found
I have no idea what's going on!
I guess this isn't possible in a script? edit: sorry, feeling a bit defeatist this morning
You're testing the result of echo $?, not the result of grep.
Code:$ echo $var | grep -q zarniwoop $ if [ $? -eq 0 ]; then echo yes; else echo no ; fi no $ echo $var | grep -q firefox $ if [ $? -eq 0 ]; then echo yes; else echo no ; fi yes
If you dance barefoot on the broken glass of undefined behaviour, you've got to expect the occasional cut.
If at first you don't succeed, try writing your phone number on the exam paper.
Ah, yup, that's working, many thanks Salem.
