Hack 91. Ps Command Examples

by Ramesh

ps command (process status) will display snapshot information of all active processes.

  1. Syntax: ps [options]

How to display all the processes running in the system?

Use “ps aux”, as shown below.

  1. # ps aux | more
  2. USER       PID %CPU %MEM    VSZ    RSS TTY  STAT START  TIME COMMAND
  3. root               1       0.0         0.0    2044     588 ?        Ss        Jun27      0:00  init [5]         
  4. apache   31186       0.0        1.6  23736 17556 ?        S          Jul26       0:40  /usr/local/apache2/bin/httpd
  5. apache   31187       0.0        1.3  20640 14444 ?        S          Jul26       0:37  /usr/local/apache2/bin/httpd

You can also use “ps -ef | more”, to get a similar output

Print the Process Tree

You can use either ps axuf or ps –ejH to display processes in a tree format. The tree structure will help to visualize the process and it’s parent process immediately. For clarity purpose, few columns have been cut-off in the output below.

  1. # ps axuf
  2.  
  3. root     Oct14   0:00 /opt/VRTSralus/bin/beremote
  4. root     Oct14   0:00  \_ /opt/VRTSralus/bin/beremote
  5. root     Oct14   0:00      \_ /opt/VRTSralus/bin/beremote
  6. root     Oct14   0:00      \_ /opt/VRTSralus/bin/beremote
  7. root     Oct14   0:01      \_ /opt/VRTSralus/bin/beremote
  8. root     Oct 14  0:00      \_ /opt/VRTSralus/bin/beremote
  9. root     Dec03   0:01 /usr/local/sbin/sshd
  10. root     Dec22   1:08 /usr/local/sbin/sshd
  11. root     23:35   0:00  \_ /usr/local/sbin/sshd
  12. 511      23:35   0:00      \_ -bash
  13. 511                           \_ ps axuf

Note: You can also use pstree command to display process in tree structure.

View Processes Owned by a Particular User

The following command displays all the process owned by Linux user-name: oracle.

  1. $ ps U oracle
  2.  
  3. PID TTY      STAT   TIME COMMAND
  4. 5014 ?        Ss     0:01 /oracle/bin/tnslsnr
  5.   7124 ?        Ss     0:00 ora_q002_med
  6. 8206 ?        Ss     0:00 ora_cjq0_med
  7. 8852 ?        Ss     0:01 ora_pmon_med
  8. 8854 ?        Ss     0:00 ora_psp0_med
  9. 8911 ?        Ss     0:02 oraclemed (LOCAL=NO)

View Processes Owned by Current User

Following command displays all the process owned by the current user.

  1. $ ps U $USER
  2.  
  3. PID TTY      STAT   TIME COMMAND
  4. 10329 ?        S      0:00 sshd: ramesh@pts/1,pts/2
  5. 10330 pts/1    Ss     0:00 -bash
  6. 10354 pts/2    Ss+    0:00 -bash
  7. 10530 pts/1    R+     0:00 ps U ramesh