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ドル}'`

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.

Answer 1

Just grep away grep itself!

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

• Mayank Jain: 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
• blue: Surely you can think of something to "grep away" again, as the PID of your script, which should be available via the $$ variable
• chepner: 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 ....

Answer 2

Have you tried to use pidof ABCD ?

• blue: this is actually a better answer for most cases :)
• Kevin Campion: Or pgrep ABCD
• s3n0: 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.

Answer 3

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ドル }')
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.

Answer 4

ps has an option for that:

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

Answer 5

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ドル}'

Answer 6

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ドル }'`
echo $b

Answer 7

I found a better way to do this.

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

Answer 8

ps | pgrep ABCD

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

Answer 9

You can use 'pgrep #prog_name' instead and it shall return prog_name PID directly.

Answer 10

If you got below,

$ ps -ef | grep test
root 1322 1 0 10:31:17 ? 00:00:38 sh /test.sh
root 9078 8593 4 18:17:24 pts/1 00:00:00 grep switch

then, try this.

$ echo $(pgrep -f test.sh)
1332