How to get only process ID in specify process name in Linux?

Question

How to get only the process ID for a specified process name in Linux?

ps -ef|grep java
test 31372 31265  0 13:41 pts/1    00:00:00 grep java

Based on the process id I will write some logic. So how do I get only the process id for a specific process name.

Sample program:

PIDS= ps -ef|grep java
if [ -z "$PIDS" ]; then
echo "nothing"
else
mail test@domain.example
fi

score 106 · Answer 1 · answered Sep 09 '14 at 18:07

106

You can pipe your output to awk to print just the PID. For example:

ps -ef | grep nginx | awk '{print $2}'
9439

answered Sep 09 '14 at 18:07

Jose Varez

Works well, hoverver if you use the output as a variable, a | tr -d '\n' must be added at the end of the command. – рüффп Jul 20 '20 at 09:46
It is a program that can be used to select particular records in a file and perform operations upon them. It is so extensive that you can even write some programs with it. [AWK Documentation](https://www.gnu.org/software/gawk/manual/gawk.html) – Gilberto Treviño Jul 01 '21 at 12:45

score 104 · Accepted Answer · answered Sep 09 '14 at 18:04

104

You can use:

ps -ef | grep '[j]ava'

Or if pgrep is available then better to use:

pgrep -f java

answered Sep 09 '14 at 18:04

anubhava

1

Great answer pgrep -f java . It can be used to get PID only. – DollyShukla Feb 24 '21 at 10:02
1

Your first answer doesn't return only the pid, it returns all informations (on Ubuntu). BTW: Could you explain, what the brackets do? II couldn't find a doc for it. – dur Oct 15 '21 at 10:55
Square brackets are used to exclude grep process from ps output – anubhava Oct 15 '21 at 11:07

score 76 · Answer 3 · answered Sep 09 '14 at 18:06

76

Use this: ps -C <name> -o pid=

answered Sep 09 '14 at 18:06

ventsyv

16

Why is this voted down? Not only does it seem to work, but does so using the desired command ps, and no pipe filters. In my case, I couldn't use pipes (reasons..) so this was a lifesaver. You could spend a whole day reading the man page for PS... thanks @ventsyv – Scott Prive Jul 29 '16 at 21:57
2

Maybe because it's not extremely portable, but then again the other solutions aren't either, and the original question was tagged with Redhat Linux. Just happened to see a commit by one of my engineers who needed to have a portable way to detect a specific java process on OSX, RHEL Linux and AIX, and this is what they came up with: `ps -A -o pid,args | grep \[j]ava`. – ikaerom Jun 05 '17 at 10:51

score 25 · Answer 4 · answered Sep 15 '18 at 21:40

25

This command ignore grep process, and just return PID:

ps -ef | grep -v grep | grep java | awk '{print $2}'

answered Sep 15 '18 at 21:40

Nabi K.A.Z.

1

Shorter: ps -ef | grep '[j]ava' | awk '{print $2}' – Jan 05 '20 at 19:48
I use this to get the PID. Be careful when using the output as a variable, a `| tr -d '\n'` must be added at the end. – рüффп Jul 20 '20 at 09:45
On busybox v1.24.1 , this worked for me: ps | grep -v grep | grep cli | awk '{print $1}' – Arkham Angel Nov 17 '21 at 19:07
And this: ps | awk '$NF ~ /cli/ {print $1}' – Arkham Angel Nov 17 '21 at 19:51
1

Thanks for this comment, the ignore grep processes was a nice addition. – Arthur Bowers Apr 20 '22 at 09:30

score 21 · Answer 5 · answered Nov 23 '18 at 09:44

21

why not just pidof ?

pidof <process_name>

it will return a list of pids matching the process name

answered Nov 23 '18 at 09:44

NIEL Alexandre

Clean and quick on Ubuntu 16.04 – sashaboulouds Sep 17 '19 at 17:30
2

works as long you don't have multiple instance (e.g. java) – рüффп Jul 20 '20 at 09:44

5 Answers5