ps [-AaCcEefhjlMmrSTvwXx] [-O fmt | -o fmt] [-G gid [,gid...]] [-g grp [,grp...]] [-u uid [,uid...]] [-p pid [,pid...]] [-t tty [,tty...]] [-U user [,user...]]
For the processes which have been selected for display, the default information to display includes:
The process ID (PID), the controlling terminal (TTY), the CPU time the process has used, and the associated command.

The ps command supports three different types of options:

• Unix-style options: they are preceded by a dash character (-f, ...).
  
• BSD-style options: they are not preceded by a dash character (x, ...).
  
• GNU long options: they are preceded by a double dash characters (--forest, ...).
  

Here's a list of some the headers that are displayed by the ps command:

• UID: the user that started the process.
  
• PID: the process ID.
  
• PPID: the process ID of the parent of the process.
  
• C: the utilization of the processor.
  
• STIME: the system time when the process started.
  
• TTY: the terminal that started the process.
  
• TIME: the total time required to run the process.
  
• CMD: the command that started the process.
  

Extra headers can be shown with the option -l:

• F: the system flags assigned to the process by the kernel.
  
• S: the state of the process (O: running, S: sleeping, R: runnable, Z: zombie, T: stopped).
  
• PRI: the priority of the process (lower numbers means higher priority).
  
• NI: the nice value.
  
• ADDR: the memory address of the process.
  
• SZ: the swap space required by the process.
  
• WCHAN: the address of the kernel where the process is sleeping.
  

The BSD-style option l show a special header STAT that display the state of the process using two characters:

• The first character shows the state of the process (O: running, S: sleeping, R: runnable, Z: zombie, T: stopped).
  
• The second character shows the status of the process:
  
  • <: the process is running at high priority.
    
  • N: the process is running at low priority.
    
  • L: the process has pages locked in memory.
    
  • s: the process is a session leader.
    
  • l: the process is multi-threaded.
    
  • +: the process is running in the foreground.
    

• List processes that belongs to the current user and running on the current terminal:
  
  
  • Default output:
    $ ps PID TTY TIME CMD 5355 pts/0 00:00:00 bash 7719 pts/0 00:00:00 ps
    
  • Full-format:
    $ ps -f UID PID PPID C STIME TTY TIME CMD mtitek 5355 5354 0 14:57 pts/0 00:00:00 -bash mtitek 7706 5355 0 18:51 pts/0 00:00:00 ps -f
    
  • Long format (Unix-style option):
    $ ps -l F S UID PID PPID C PRI NI ADDR SZ WCHAN TTY TIME CMD 0 S 1000 5355 5354 0 80 0 - 5732 wait pts/0 00:00:00 bash 0 R 1000 7708 5355 0 80 0 - 7230 - pts/0 00:00:00 ps
    
  • Long format (BSD-style option):
    $ ps l F UID PID PPID PRI NI VSZ RSS WCHAN STAT TTY TIME COMMAND 0 1000 5355 5354 20 0 22928 5512 wait Ss pts/0 0:00 -bash 0 1000 9642 5355 20 0 28920 1484 - R+ pts/0 0:00 ps l
    
• List processes that belongs to the current user including processes without a terminal device assigned:
  $ ps x PID TTY STAT TIME COMMAND 5258 ? Ss 0:00 /lib/systemd/systemd --user 5259 ? S 0:00 (sd-pam) 5354 ? R 0:00 sshd: mtitek@pts/0 5355 pts/0 Ss 0:00 -bash 7980 pts/0 R+ 0:00 ps x
  
• Display processes hierarchy (the relationship between processes is drawn using ASCII characters):
  $ ps x --forest PID TTY STAT TIME COMMAND 5354 ? S 0:00 sshd: mtitek@pts/0 5355 pts/0 Ss 0:00 \_ -bash 8128 pts/0 R+ 0:00 \_ ps x --forest 5258 ? Ss 0:00 /lib/systemd/systemd --user 5259 ? S 0:00 \_ (sd-pam)
  
• List all processes:
  $ ps -e
  $ ps -A
  
• List PID processes:
  $ ps | grep bash | grep -v grep | awk '{print $1}' 17190 $ ps | grep bash | grep -v grep | awk {'print $1 " " $2 " " $3 " " $4 " " $5 '} 17190 pts/0 00:00:00 bash
  $ ps | grep bash | grep -v grep | colrm 6 17190
  $ for pid in `ps -e -f | grep mongodb | grep -v grep | awk '{print $2}'`; do echo "PID: $pid"; done PID: 19034
  
• Kill processes:
  $ for pid in `ps -e -f | grep mongodb | grep -v grep | awk '{print $2}'`; do kill -9 $pid; done

Basic options:
-A, -e all processes -a all with tty, except session leaders a all with tty, including other users -d all except session leaders -N, --deselect negate selection r only running processes T all processes on this terminal x processes without controlling ttys
Selection by list:
-C <command> command name -G, --Group <GID> real group id or name -g, --group <group> session or effective group name -p, p, --pid <PID> process id --ppid <PID> parent process id -q, q, --quick-pid <PID> process id (quick mode) -s, --sid <session> session id -t, t, --tty <tty> terminal -u, U, --user <UID> effective user id or name -U, --User <UID> real user id or name
The selection options take as their argument either:
- a comma-separated list e.g. '-u root,nobody'
- or a blank-separated list e.g. '-p 123 4567'

Output formats:
-F extra full -f full-format, including command lines f, --forest ascii art process tree -H show process hierarchy -j jobs format j BSD job control format -l long format l BSD long format -M, Z add security data (for SELinux) -O <format> preloaded with default columns O <format> as -O, with BSD personality -o, o, --format <format> user-defined format s signal format u user-oriented format v virtual memory format X register format -y do not show flags, show rss vs. addr (used with -l) --context display security context (for SELinux) --headers repeat header lines, one per page --no-headers do not print header at all --cols, --columns, --width <num> set screen width --rows, --lines <num> set screen height
Show threads:
H as if they were processes -L possibly with LWP and NLWP columns -m, m after processes -T possibly with SPID column
Miscellaneous options:
-c show scheduling class with -l option c show true command name e show the environment after command k, --sort specify sort order as: [+|-]key[,[+|-]key[,...]] L show format specifiers n display numeric uid and wchan S, --cumulative include some dead child process data -y do not show flags, show rss (only with -l) -V, V, --version display version information and exit -w, w unlimited output width --help <simple|list|output|threads|misc|all> display help and exit