linux ps user,PS--Linux User's Manual

PS(1) Linux User's

Manual PS(1)

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 preceded by a dash.

2 BSD options, which may be

grouped and must not be used with a dash.

3 GNU long options, which are

preceded by two dashes.

Options of different types may be freely mixed, but conflicts

can appear.

There are some synonymous 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=EUID) as the current user and associated with the same

terminal as the

invoker. It displays the process ID (pid=PID), the terminal

associated with

the process (tname=TTY), the cumulated CPU time in [dd-]hh:mm:ss

format

(time=TIME), and the executable name (ucmd=CMD). Output is unsorted

by

default.

The use of BSD-style options will add process state (stat=STAT)

to the default

display and show the command args (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

-A Select all processes. Identical to -e.

-N Select all processes except those that fulfill the specified

conditions. (negates the selection) Identical to --deselect.

T Select all processes associated with this terminal. Identical

to the t option without any argument.

-a Select all processes except session leaders (see getsid(2))

and processes not associated with a terminal.

a Lift the BSD-style "only yourself" restriction, which is

imposed upon the set of all processes when some BSD-style

(without "-") options are used or when the ps personality

setting is BSD-like. The set of processes selected in this

manner is in addition to the set of processes selected by

other means. An alternate description is that this option

causes ps to list all processes with a terminal (tty), or to

list all processes when used together with the x option.

-d Select all processes except session leaders.

-e Select all processes. Identical to -A.

g Really all, even session leaders. This flag is obsolete and

may be discontinued in a future release. It is normally

implied by the a flag, and is only useful when operating in

the sunos4 personality.

r Restrict the selection to only running processes.

x Lift the BSD-style "must have a tty" restriction, which is

imposed upon the set of all processes when some BSD-style

(without "-") options are used or when the ps personality

setting is BSD-like. The set of processes selected in this

manner is in addition to the set of processes selected by

other means. An alternate description is that this option

causes ps to list all processes owned by you (same EUID as

ps), or to list all processes when used together with the a

option.

--deselect Select all processes except those that fulfill the specified

conditions. (negates the selection) Identical to -N.

PROCESS SELECTION BY LIST

These options accept a single argument in the form of a

blank-separated or

comma-separated list. They can be used multiple times.

For example: ps -p "1 2" -p 3,4

-C

cmdlist Select by command name.

This selects the processes whose executable name is given in

cmdlist.

-G

grplist Select by real group ID (RGID) or name.

This selects the processes whose real group name or ID is in

the grplist list. The real group ID identifies the group of

the user who created the process, see getgid(2).

U

userlist Select by effective user ID (EUID) or name.

This selects the processes whose effective user name or ID is

in userlist. The effective user ID describes the user whose

file access permissions are used by the process

(see geteuid(2)). Identical to -u and --user.

-U

userlist select by real user ID (RUID) or name.

It selects the processes whose real user name or ID is in the

userlist list. The real user ID identifies the user who

created the process, see getuid(2).

-g

grplist Select by session OR by effective group name.

Selection by session is specified by many standards, but

selection by effective group is the logical behavior that

several other operating systems use. This ps will select by

session when the list is completely numeric (as sessions

are).

Group ID numbers will work only when some group names are

also

specified. See the -s and --group options.

p

pidlist Select by process ID. Identical to -p and --pid.

-p

pidlist Select by PID.

This selects the processes whose process ID numbers appear in

pidlist. Identical to p and --pid.

-s

sesslist Select by session ID.

This selects the processes with a session ID specified

in sesslist.

t

ttylist Select by tty. Nearly identical to -t and --tty, but can also

be used with an empty ttylist to indicate the terminal

associated with ps. Using the T option is considered cleaner

than using T with an empty ttylist.

-t

ttylist Select by tty.

This selects the processes associated with the terminals

given

in ttylist. Terminals (ttys, or screens for text output) can

be specified in several forms: /dev/ttyS1, ttyS1, S1. A plain

"-" may be used to select processes not attached to any

terminal.

-u

userlist Select by effective user ID (EUID) or name.

This selects the processes whose effective user name or ID is

in userlist. The effective user ID describes the user whose

file access permissions are used by the process

(see geteuid(2)). Identical to U and --user.

--Group grplist Select by real group ID (RGID) or name. Identical

to -G.

--User userlist Select by real user ID (RUID) or name. Identical to

-U.

--group grplist Select by effective group ID (EGID) or name.

This selects the processes whose effective group name or ID

is

in grouplist. The effective group ID describes the group

whose

file access permissions are used by the process

(see geteuid(2)). The -g option is often an alternative

to --group.

--pid pidlist Select by process

ID. Identical to -p and p.

--ppid pidlist Select by parent process ID. This

selects the processes with a

parent process ID in pidlist. That is, it selects processes

that are children of those listed in pidlist.

--sid sesslist Select by session ID. Identical to

-s.

--tty ttylist Select by

terminal. Identical to -t and t.

--user userlist Select by effective user ID (EUID) or name.

Identical to -u

and U.

-123 Identical to --sid 123.

123 Identical to --pid 123.

OUTPUT FORMAT CONTROL

These options are used to choose the information displayed by ps.

The output

may differ by personality.

-F extra full format. See the -f option, which -F implies.

-O

format is like -o, but preloaded with some default columns.

Identical

to -o pid,format,state,tname,time,command or

-o pid,format,tname,time,cmd, see -o below.

O

format is preloaded o (overloaded).

The BSD O option can act like -O (user-defined output format

with some common fields predefined) or can be used to specify

sort order. Heuristics are used to determine the behavior of

this option. To ensure that the desired behavior is obtained

(sorting or formatting), specify the option in some other way

(e.g. with -O or --sort). When used as a formatting option,

it

is identical to -O, with the BSD personality.

-M Add a column of security data. Identical to Z. (for SE Linux)

X Register format.

Z Add a column of security data. Identical to -M. (for SE Linux)

-c Show different scheduler information for the -l option.

-f does full-format listing. This option can be combined with

many other UNIX-style options to add additional columns. It

also causes the command arguments to be printed. When used

with -L, the NLWP (number of threads) and LWP (thread ID)

columns will be added. See the c option, the format keyword

args, and the format keyword comm.

j BSD job control format.

-j jobs format

l display BSD long format.

-l long format. The -y option is often useful with this.

o

format specify user-defined format. Identical to -o and --format.

-o

format user-defined format.

format is a single argument in the form of a blank-separated

or comma-separated list, which offers a way to specify

individual output columns. The recognized keywords are

described in the STANDARD FORMAT SPECIFIERS section below.

Headers may be renamed

(ps -o pid,ruser=RealUser -o comm=Command) as desired. If all

column headers are empty (ps -o pid= -o comm=) then the

header

line will not be output. Column width will increase as needed

for wide headers; this may be used to widen up columns such

as

WCHAN (ps -o pid,wchan=WIDE-WCHAN-COLUMN -o comm). Explicit

width control (ps opid,wchan:42,cmd) is offered too. The

behavior of ps -o pid=X,comm=Y varies with personality;

output

may be one column named "X,comm=Y" or two columns named "X"

and "Y". Use multiple -o options when in doubt. Use the

PS_FORMAT environment variable to specify a default as

desired; DefSysV and DefBSD are macros that may be used to