ps Command in Linux with Examples

ps Command

ps command is used to find the running processes of the system.

Syntax

ps

ps without any option

This is a very basic ps usage. It shows you process ID (PID), TTY command running place, Time and CMD.

Example

[user1@linuxhelp ~]$ps 
PID   TTY      TIME      CMD
7822  pts/3    00:00:00  su
7831  pts/3    00:00:00  bash
13061 pts/3    00:00:00  ps

This information is unsorted result.

Current Processes

The following command is used to view all the current running processes.
Option ' f' is used to display the detailed information about the process

Example

[user1@linuxhelp ~]$ ps ax 
PID  TTY       STAT    TIME  COMMAND
1     ?        Ss     0:01  /sbin/init
2     ?        S      0:00  [kthreadd]
3     ?        S      0:00  [migration/0]
4     ?        S      0:00  [ksoftirqd/0]
5     ?        S      0:00  [migration/0]
[user1@linuxhelp ~]$ ps -ef  -f 
UID        PID  PPID  C STIME TTY          TIME CMD
root         1     0  0 09:14 ?        00:00:01 /sbin/init
root         2     0  0 09:14 ?        00:00:00 [kthreadd]
root         3     2  0 09:14 ?        00:00:00 [migration/0]
root         4     2  0 09:14 ?        00:00:00 [ksoftirqd/0]
root         5     2  0 09:14 ?        00:00:00 [migration/0]

Filter User Processes

The following command is used to filter a specific user processes

Example

[user1@linuxhelp ~]$ ps  -u  user1 
PID  TTY      TIME      CMD
3161 pts/0    00:00:00  bash
3345 pts/0    00:00:00  ps

Filter Processes by CPU or Memory usage

The following command is used to filter the processes by CPU or memory.

Example

[user1@linuxhelp ~]$ ps aux | less
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.1  0.0  19336   792 ?        Ss   09:14   0:01 /sbin/init
root         2  0.0  0.0      0     0 ?        S    09:14   0:00 [kthreadd]
root         3  0.0  0.0      0     0 ?        S    09:14   0:00 [migration/0]
root         4  0.0  0.0      0     0 ?        S    09:14   0:00 [ksoftirqd/0]
root         5  0.0  0.0      0     0 ?        S    09:14   0:00 [migration/0]

Sort processes by highest CPU utilization

The following command is used to sort the processes by highest CPU utilization.

Example

[user1@linuxhelp ~]$ ps aux --sort &ndash pcpu | less 
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root      3194 10.7 43.7 1198736 442508 ?      Sl   09:28   1:22 /usr/lib64/fire
fox/firefox
root      2336  1.6  6.5 164912 66060 tty1     Ss+  09:14   0:26 /usr/bin/Xorg :
0 -nr -verbose -audit 4 -auth /var/run/gdm/auth-for-gdm-ruguYX/database -noliste
n tcp vt1
root      3094  0.8  7.2 1108696 73600 ?       Sl   09:25   0:07 /usr/lib64/libr
eoffice/program/soffice.bin --writer file:///root/Desktop/ps_commands.docx --spl
ash-pipe=7

To Sort processes by highest memory utilization

The following command is used to sort the processes by highest memory utilization.

Example

[user1@linuxhelp ~]$ ps aux --sort &ndash pmem | less 
USER       PID %CPU %MEM    VSZ   RSS TTY      STAT START   TIME COMMAND
root         1  0.0  0.0  19336   960 ?        Ss   09:14   0:01 /sbin/init
root         2  0.0  0.0      0     0 ?        S    09:14   0:00 [kthreadd]
root         3  0.0  0.0      0     0 ?        S    09:14   0:00 [migration/0]
root         4  0.0  0.0      0     0 ?        S    09:14   0:00 [ksoftirqd/0]
root         5  0.0  0.0      0     0 ?        S    09:14   0:00 [migration/0]

Filter Processes by name

The following command is used to filter processes by name.

Example

[user1@linuxhelp Desktop]# ps  -C  init 
PID TTY          TIME CMD
1 ?        00:00:01 init
[user1@linuxhelp Desktop]# ps -f -C firefox
UID        PID  PPID  C STIME TTY          TIME CMD
root      3194     1  9 09:28 ?        00:04:10 /usr/lib64/firefox/firefox

To show it in a full formatting list option -f option can be used along with it.

Process Thread

The following command is used to view the thread of the particular process.

Example

[user1@linuxhelp Desktop]# ps  -L  3194 
 PID   LWP TTY      STAT   TIME COMMAND
 3194  3194 ?        Sl     3:36 /usr/lib64/firefox/firefox
 3194  3213 ?        Sl     0:00 /usr/lib64/firefox/firefox
 3194  3214 ?        Sl     0:04 /usr/lib64/firefox/firefox
 3194  3215 ?        Sl     0:11 /usr/lib64/firefox/firefox
 3194  3216 ?        Sl     0:03 /usr/lib64/firefox/firefox
 3194  3217 ?        Sl     0:00 /usr/lib64/firefox/firefox
 3194  3218 ?        Sl     0:00 /usr/lib64/firefox/firefox

Processes Hierarchy

The following command is used to view the processes in hierarchical form.

Example

[user1@linuxhelp Desktop]# pstree 
init???NetworkManager
     ??abrtd
     ??acpid
     ??atd
     ??auditd???{auditd}
     ??automount???4*[{automount}]
     ??bonobo-activati???{bonobo-activat}
     ??certmonger
     ??clock-applet
     ??console-kit-dae???63*[{console-kit-da}]
[user1@linuxhelp ~]$ ps  axjf 
 PPID   PID  PGID   SID TTY      TPGID STAT   UID   TIME COMMAND
    0     2     0     0 ?           -1 S        0   0:00 [kthreadd]
    2     3     0     0 ?           -1 S        0   0:00  \_ [migration/0]
    2     4     0     0 ?           -1 S        0   0:00  \_ [ksoftirqd/0]
    2     5     0     0 ?           -1 S        0   0:00  \_ [migration/0]
    2     6     0     0 ?           -1 S        0   0:00  \_ [watchdog/0]
    2     7     0     0 ?           -1 S        0   0:04  \_ [events/0]
    2     8     0     0 ?           -1 S        0   0:00  \_ [cgroup]
    2     9     0     0 ?           -1 S        0   0:00  \_ [khelper]
    2    10     0     0 ?           -1 S        0   0:00  \_ [netns]

User Running the application

The following command is used to view the user who’ s the running the application with PID.

Example

[user1@linuxhelp ~]$ ps -eo pid,user,args 
PID USER     COMMAND
  1 root     /sbin/init
  2 root     [kthreadd]
  3 root     [migration/0]
  4 root     [ksoftirqd/0]
  5 root     [migration/0]