Bash: how to check if a process id (PID) exists

Posted by Richard on Stack Overflow See other posts from Stack Overflow or by Richard
Published on 2010-06-15T09:30:26Z Indexed on 2010/06/15 9:42 UTC
Read the original article Hit count: 228

Filed under:

bash

|

pid

Hi All,

In a bash script i want to do the following (in pseudo-code):

if [ a process exists with $PID ]; then

    kill $PID 

fi

What's the appropriate bash for the conditional statement?

Thanks

© Stack Overflow 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 pid

How to allow bind in app armor?

as seen on Ask Ubuntu - Search for 'Ask Ubuntu'
Question: I did setup bind9 as described here: http://ubuntuforums.org/showthread.php?p=12149576#post12149576 Now I have a little problem with apparmor: If I switch it off, it works. If apparmor runs, it doesn't work, and I get the following dmesg output: [ 23.809767] type=1400 audit(1344097913… >>> More
Creating multiple process and simulation in C via fork()

as seen on Stack Overflow - Search for 'Stack Overflow'
i want to create multiple process groups which will call different functions. i write the code below. firstly i want to get following output ./fork 4 5 I am a child: 1 PID: 22330 I am a child2: 1 PID: 22334 I am a child: 2 PID: 22331 I am a child2: 5 PID: 22338 I am a child: 4 PID: 22333 … >>> More
How to resolve high CPU + excessive stat("/etc/localtime") and clock_gettime(CLOCK_REALTIME) calls

as seen on Server Fault - Search for 'Server Fault'
I've been experiencing really high CPU on a ruby on rails app (see stack below) and have been trying to diagnose the possible causes to no avail. Stack: ruby 1.9.3 rails 3.2.6 Apache/2.2.21 (Debian) Phusion Passenger 3.0.11 Whenever I run strace against the spiking Rack process PID (see Top… >>> More
Identify PID of a transient network connection on HPUX 11.23

as seen on Server Fault - Search for 'Server Fault'
We've tried lsof and tcpdump to capture the PID of a process that is attempting to make connections. Any ideas? >>> More
Identify PID of a transient network connection on HPUX 11.23

as seen on Stack Overflow - Search for 'Stack Overflow'
We've tried lsof and tcpdump to capture the PID of a process that is attempting to make connections. Any ideas? >>> More