ps

This article is a stub. Please help out by expanding it - how to get started.

Resources

ps (short for process status) is a tool for reporting on a system's active processes. It has a long history on Unix-like operating systems such as BSD and Linux. Consequently, it accepts a very wide variety of input flags in one of three forms: Unix-style options preceded by a single dash, BSD-style options which do not have a dash, and GNU long options which are preceded by two dashes.

Installation

USE flags

USE flags for sys-process/procps Standard informational utilities and process-handling tools

+kill Build the kill program

+ncurses Build programs that use ncurses: top, slabtop, watch

elogind Use sys-auth/elogind for session tracking.

modern-top Enables new startup defaults of top. Keeps old defaults if disabled

nls Add Native Language Support (using gettext - GNU locale utilities)

selinux !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur

skill Build the skill and snice programs

static-libs Build static versions of dynamic libraries as well

systemd Enable use of systemd-specific libraries and features like socket activation or session tracking

test Enable dependencies and/or preparations necessary to run tests (usually controlled by FEATURES=test but can be toggled independently)

unicode Add support for Unicode

verify-sig Verify upstream signatures on distfiles

Data provided by the Gentoo Package Database · Last update: 2026年04月05日 04:42 More information about USE flags

Emerge

sys-process/procps is part of the @system set, so it should be installed by default.

In case it is ever needed, reinstall sys-process/procps :

root #emerge --ask --oneshot sys-process/procps

Configuration

Environment variables

$PS_FORMAT — override the default output format.

Files

/proc — the virtual file system ps reads to obtain the information required for its reports.

Usage

Invocation

To see options available to the ps command:

user $ps --help all

Usage:
 ps [options]
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
For more details see ps(1).

Show all running processes

ps may be used to show all running processes by using the a, u, and x, options (see invocation section on what these options do):

user $ps aux

Tips

Find a specific process

To find details of a specific process by name, the ps command output may be piped to grep:

user $ps aux | grep <process name>

ps

Contents