Getting PID of process in Shell Script

Question

I am writing one shell script and I want to get PID of one process with name as "ABCD". What i did was :

process_id=`/bin/ps -fu $USER|grep "ABCD"|awk '{print $2}'`

This gets PID of two processes i.e. of process ABCD and the GREP command itself what if I don't want to get PID of GREP executed and I want PID only of ABCD process?

Please suggest.

score 56 · Accepted Answer · answered Jun 06 '13 at 14:45

56

Just grep away grep itself!

process_id=`/bin/ps -fu $USER| grep "ABCD" | grep -v "grep" | awk '{print $2}'`

answered Jun 06 '13 at 14:45

blue

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Thanks for quick Answer.It worked.Also what if i dont want PID of script which is executing this. Because my script also contains ABCD – Mayank Jain Jun 06 '13 at 14:49
Surely you can think of something to "grep away" again, as the PID of your script, which should be available via the `$$` variable – blue Jun 06 '13 at 14:57
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A trick for avoiding the 2nd grep is to give `grep` a regular expression that matches the same thing, but appears different on the command line: `... | grep "[A]BCD" | awk ...`. – chepner Jun 06 '13 at 17:28

score 33 · Answer 2 · answered Jun 06 '13 at 15:39

33

Have you tried to use pidof ABCD ?

answered Jun 06 '13 at 15:39

wizard

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this is actually a better answer for most cases :) – blue Oct 23 '15 at 12:13
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Or `pgrep ABCD` – Kevin Campion Sep 20 '18 at 19:51
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The `pidof` command does not behave the same on every Linux distribution. So using `pidof` is not a good solution. It is also necessary to distinguish between the version of `ps` included in BusyBox - in lightweight Linux distributions (for example in a set-top box) and another `ps`, which is designed for full-fledged Linux. In the BusyBox version of the `ps` command, almost no arguments / switches work. In the case of BusyBox, the `ps` command is used a little differently. You have to be careful. – s3n0 Mar 20 '22 at 13:29

score 9 · Answer 3 · edited Dec 17 '19 at 21:48

9

It's very straight forward. ABCD should be replaced by your process name.

#!/bin/bash

processId=$(ps -ef | grep 'ABCD' | grep -v 'grep' | awk '{ printf $2 }')
echo $processId

Sometimes you need to replace ABCD by software name. Example - if you run a java program like java -jar TestJar.jar & then you need to replace ABCD by TestJar.jar.

edited Dec 17 '19 at 21:48

Alex Zavatone

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answered Feb 20 '17 at 11:26

A M S Rejuan

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Salvador Fonseca · Answer 4 · 2017-08-02T22:54:26.220

2

ps has an option for that:

process_id=`/bin/ps -C ABCD -o pid=`

edited Aug 02 '17 at 22:54

answered Aug 02 '17 at 22:48

Salvador Fonseca

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score 2 · Answer 5 · answered Jan 31 '19 at 02:31

2

You can also do away with grep and use only awk.
Use awk's expression matching to match the process name but not itself.

/bin/ps -fu $USER | awk '/ABCD/ && !/awk/ {print $2}'

answered Jan 31 '19 at 02:31

Gino Mempin

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score 1 · Answer 6 · edited Oct 11 '19 at 12:15

1

You can use this command to grep the pid of a particular process & echo $b to print pid of any running process:

b=`ps -ef | grep [A]BCD | awk '{ printf $2 }'`
echo $b

edited Oct 11 '19 at 12:15

Sébastien Le Callonnec

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answered Nov 14 '14 at 18:33

Sandeep Singh

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score 1 · Answer 7 · answered Sep 16 '20 at 12:18

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ps | pgrep ABCD

You can try the above command to return the process id of the ABCD process.

answered Sep 16 '20 at 12:18

Leenu

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score 1 · Answer 8 · answered May 03 '21 at 06:30

1

I found a better way to do this.

top -n 1 | grep "@#" | grep -Eo '^[^ ]+'

answered May 03 '21 at 06:30

Varun Nair

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Getting PID of process in Shell Script

8 Answers8