PS
Section: Linux User's Manual (1)
Updated: July 28, 2004
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NAME
ps - report a snapshot of the current processes.
SYNOPSIS
ps [options]
DESCRIPTION
ps
displays information about a selection of the active processes.
If you want a repetitive update of the selection and the
displayed information, use top(1) instead.
This version of ps accepts several kinds of options:
- 1
-
UNIX options, which may be grouped and must be preceeded by a dash.
- 2
-
BSD options, which may be grouped and must not be used with a dash.
- 3
-
GNU long options, which are preceeded by two dashes.
Options of different types may be freely mixed, but conflicts can appear.
There are some synonomous options, which are functionally identical, due
to the many standards and ps implementations that this ps is
compatible with.
Note that "ps -aux" is distinct from "ps aux".
The POSIX and UNIX standards require that "ps -aux" print all
processes owned by a user named "x", as well as printing all processes
that would be selected by the -a option. If the user named "x" does
not exist, this ps may interpret the command as "ps aux"
instead and print a warning. This behavior is intended to aid in
transitioning old scripts and habits. It is fragile, subject to change,
and thus should not be relied upon.
By default, ps selects all processes with the same effective user
ID (EUID) as the curent user and associated with the same terminal as the
invoker. It displays the process ID (PID), the terminal associated
with the process (TTY), the cumulated CPU time in [dd-]hh:mm:ss format
(TIME), and the executable name (CMD). Output is unsorted by default.
The use of BSD-style options will add process state (STAT) to the
default display and show the command args (COMMAND) instead of the
executable name. You can override this with the PS_FORMAT
environment variable. The use of BSD-style options will also change the
process selection to include processes on other terminals (TTYs) that
are owned by you; alternately, this may be described as setting the
selection to be the set of all processes filtered to exclude
processes owned by other users or not on a terminal. These effects
are not considered when options are described as being "identical" below,
so -M will be considered identical to Z and so on.
Except as described below, process selection options are additive.
The default selection is discarded, and then the selected processes
are added to the set of processes to be displayed.
A process will thus be shown if it meets any of the given
selection criteria.
EXAMPLES
- To see every process on the system using standard syntax:
-
ps -e
ps -ef
ps -eF
ps -ely
- To see every process on the system using BSD syntax:
-
ps ax
ps axu
- To print a process tree:
-
ps -ejH
ps axjf
- To get info about threads:
-
ps -eLf
ps axms
- To get security info:
-
ps -eo euser,ruser,suser,fuser,f,comm,label
ps axZ
ps -eM
- To see every process running as root (real & effective ID) in user format:
-
ps -U root -u root u
- To see every process with a user-defined format:
-
ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
ps -eopid,tt,user,fname,tmout,f,wchan
- Print only the process IDs of syslogd:
-
ps -C syslogd -o pid=
- Print only the name of PID 42:
-
ps -p 42 -o comm=
SIMPLE PROCESS SELECTION
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-
Select all processes. Identical to -e.
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