How to get the pid of a running process using a single command that parse the output of ps?

Posted by Sorin Sbarnea on Super User See other posts from Super User or by Sorin Sbarnea
Published on 2012-05-23T17:25:38Z Indexed on 2012/09/30 9:40 UTC
Read the original article Hit count: 242

Filed under:

bash

|

sed

|

awk

|

pid

I am looking for a single line that does return the pid of a running process.

Currently I have:

ps -A -o pid,cmd|grep xxx|head -n 1

And this returns the fist pid, command. I need only the first number from the output and ignore the rest. I suppose sed or awk would help here but my experience with them is limited.

Also, this has another problem, it will return the pid of grep if the xxx is not running.

It's really important to have a single line, as I want to reuse the output for doing something else, like killing that process.

© Super User or respective owner

Related posts about bash

launching a program from bash causes bash to go to new prompt

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
When I run a program from the console, e.g. me@box:~$ firefox I expect the console to log error messages (I think this is std out or std err?) and other items from the program, firefox in this case. But today I notice that bash just opens the program and goes to a new prompt, e.g. me@box:~$… >>> More
How to debug a .bash_profile

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I was updating my .bash_profile, and unfortunetly I made a few updates and now I am getting: env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory -bash: tar: command… >>> More
Every command fails with "command not found" after changing .bash_profile?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
I was updating my .bash_profile, and unfortunetly I made a few updates and now I am getting: env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory env: bash: No such file or directory -bash: tar: command… >>> More
Is there any fundamental difference between piping in mac and linux?

as seen on Super User - Search for 'Super User'
ps -e | grep bash sample output from a linux machine: 1128 pts/14 00:00:00 bash 7491 pts/7 00:00:00 bash 12651 pts/14 00:00:00 bash 16145 pts/2 00:00:00 bash sample output from a mac machine: 58352 ttys000 0:00.09 login -pfl username /bin/bash -c exec -la bash /bin/bash 58353 ttys000… >>> More
why is $0 set to -bash?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
First login process name seems to be set to "-bash", but if I subshell then it becomes "bash". for example: root@nowere:~# echo $0 -bash root@nowere:~# bash root@nowere:~# echo $0 bash -bash is causing some scripts to fail, such as . /usr/share/debconf/confmodule exec /usr/share/debconf/frontend… >>> More

Related posts about sed

sed + RE , want to ignore remarked line using sed

as seen on Stack Overflow - Search for 'Stack Overflow'
I want to replace the a string with the word string as the following example down , but if a string exist also after comment then a string will replaced too In which way I can add to the sed command the irregular exp that ignore from the #. [root@localhost tmp]# more test a b aa bb #a #b #aa #bb [root@localhost… >>> More
script to search and replace deprecated functions

as seen on Stack Overflow - Search for 'Stack Overflow'
Hi, I am using the following script to search and replace the deprecated functions in a file with the newer ones. 5 for strFile in `ls deprecated_functions_search_and_replace.txt ` 6 do 7 sed "s/ereg_replace[^\(]*(\([^,]*\),/preg_replace\1('#'.\2.'#',/g" $strFile > temp_file 8 … >>> More
Footer not stretching 100% when horizontally scrolled

as seen on Pro Webmasters - Search for 'Pro Webmasters'
I have a footer which is set to 100% width, but if i size the window smaller so a horizontal scrollbar appears, using the scrollbar shows whitespace to the right of the footer ... its not spanned 100% of the page, just the viewport. <!doctype html> <html lang="en" class="no-js"> <head> … >>> More
What does this regex mean and why

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
$ sed "s/\(^[a-z,0-9]*\)\(.*\)\( [a-z,0-9]*$\)/\1\2 \1/g" desired_file_name I apreciate it even if you only explain part of it or at lest structure it with words as in s\alphanumerical_at_start\something\alphanumerical_at_end\something_else\global Could someone explain what that means, why and… >>> More
Sed problem in a Bash script

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
Hello there. I'm having a problem using the sed command . I'm trying to write a bash script that does the following : search for the line that contain :@ then save the line that contained :@ and replace it with new line as in the following: #! /bin/bash echo "Please enter the ip address… >>> More