A PID is an acronym for process identification number on a Linux or Unix-like operating system. A PID is automatically assigned to each process when it is created. A process is nothing but running instance of a program and each process has a unique PID on a Unix-like system.
| Tutorial details | |
|---|---|
| Difficulty | Easy (rss) |
| Root privileges | No |
| Requirements | None |
| Estimated completion time | 2m |
The easiest way to find out if process is running is run ps aux command and grep process name. If you got output along with process name/pid, your process is running.
Task: Find out process pid
Simply use ps command as follows:
ps aux | grep {process-name}
For example find out if mysqld process (mysqld pid) is running or not:
$ ps aux | grep mysqld
Sample outputs:
mysql 28290 1.1 2.7 340496 56812 ? Sl Jul31 348:27 /usr/libexec/mysqld --defaults-file&＃61;/etc/my.cnf --basedir&＃61;/usr --datadir&＃61;/var/lib/mysql --user&＃61;mysql --pid-file&＃61;/var/run/mysqld/mysqld.pid --skip-locking --socket&＃61;/var/lib/mysql/mysql.sock
Find the process ID of a running program using pidof
pidof command finds the process id’s (pids) of the named programs. It prints those id’s on screen. This program is on some systems used in run level change scripts, especially when the system has a System-V like rc structure. In that case these scripts are located in /etc/rc?.d, where ? is the runlevel. If the system has a start-stop-daemon (8) program that should be used instead.
# pidof mysqld
Sample outputs:
28290
Find PID using pgrep command
The pgrep command searches the running system and shows the process IDs of all processes that match the given criteria. The syntax is:
pgrep {processNameHere}
pgrep firefox
pgrep httpd
pgrep nginx
Sample outputs:
4241
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{ 19 comments… add one }
hay man you can use pgrep also know?
why ps -aux | grep process name?
u can use pgrep like this
pgrep process name
pgrep httpd
pgrep named
pgrep firefox
etc
if any special about your command just give me info related to it
Thanks Surendra, damn good tips
you can also use this :
$>pkill -f cruisecontrol
in a cruisecontrol process which runs under java. -f does a substring search of the process string.
man, u guys rock, trust me it helps so much, when my maya hangs.
special thanks: adrian B, pkill -f maya: wow, toogood
Hi .
I have a probleam . when i start mysql it is showing MySQL manager or server PID file could not be found! [FAILED] . Starting MySQL/etc/init.d/mysql: line 159: kill: (5984) – No such process .how to solve the probleam. if any one know plz help me
Thank you very much for the info.. it works for me..
i tried using kill(pid,0) to test whether the process is existent, need to include
Aaron
when i reconfigure (squid -k reconfigure) squid i got error.
like this
squid: ERROR: Could not send signal 1 to process 6471: (3) No such process
how i can remove this error please help me.
Thanks in advance
hanks ive been searching the net on how to find the pid of a process and this post solve my problem. thank you
Bear in mind that the command itself can show up in the results. For instance:
mikkel&＃64;www ~ $ ps aux | grep ntp
root 20417 0.0 0.0 4408 1316 ? Ss 17:30 0:00 /usr/sbin/ntpd -p /var/run/ntpd.pid
mikkel 20429 0.0 0.0 2064 572 pts/0 S&＃43; 17:30 0:00 grep --colour&＃61;auto ntp
If you only see the grep command listed, that means the named command is not running.
Hi,
I still can’t see my pid number for my postfix services. can’t find that. Help me. Thanks.
Using: Linux server 11.04
why ? mark indicating ?? while each ps -ef |grep some process
Hii,
im facing one problem with pgrep command
I want to display the PID of process with greping on process name..im using this command for that:
pgrep -lfu $UID | grep -i AddUser | grep -v grep | grep bash | tr -s ” ” | cut -d ” ” -f1
but since the path of process AddUser is too long..the output of pgrep does not shows the fullname of process instead it crops the process name and displays only first 3 chars…Any idea to avoid cropping of process name
thanku fr d infr…
hello.i want the command for taking login name as a command line argument in linux for shell program
hello, What does ps – HI do? What is the meaning of this command?
The process could be running (it has a pid) but stopped (kill -STOP $pid) (it is not actually running).
I have a process PID i want to check this PID is for which process & the process is running or not.please explain with example
Hi All I want to know how many jobs are running on a particular server. So can anyone help me providing the command so that I could able to check how many jobs are running in the server and log status as well