ps1

Usage

Overview

The ps utility displays a header line, followed by lines containing information about all of your processes that have controlling terminals.

A different set of processes can be selected for display by using any combination of the -a, -G, -g, -p, -T, -t, -U, and -u options. If more than one of these options are given, then ps will select all processes which are matched by at least one of the given options.

For the processes which have been selected for display, ps will usually display one line per process. The -M option may result in multiple output lines (one line per thread) for some processes. By default all of these output lines are sorted first by controlling terminal, then by process ID. The -m, -r, and -v options will change the sort order. If more than one sorting option was given, then the selected processes will be sorted by the last sorting option which was specified.

For the processes which have been selected for display, the information to display is selected based on a set of keywords (see the -L, -O, and -o options). The default output format includes, for each process, the process' ID, controlling terminal, CPU time (including both user and system time), state, and associated command.

The options are as follows:

-A

Display information about other users' processes, including those without controlling terminals.

-a

Display information about other users' processes as well as your own. This will skip any processes which do not have a controlling terminal, unless the -x option is also specified.

-C

Change the way the CPU percentage is calculated by using a “raw” CPU calculation that ignores “resident” time (this normally has no effect).

-c

Change the “command” column output to just contain the executable name, rather than the full command line.

-d

Like -A, but excludes session leaders.

-E

Display the environment as well. This does not reflect changes in the environment after process launch.

-e

Identical to -A.

-f

Display the uid, pid, parent pid, recent CPU usage, process start time, controlling tty, elapsed CPU usage, and the associated command. If the -u option is also used, display the user name rather then the numeric uid. When -o or -O is used to add to the display following -f, the command field is not truncated as severely as it is in other formats.

-G

Display information about processes which are running with the specified real group IDs.

-g

Display information about processes with the specified process group leaders.

-h

Repeat the information header as often as necessary to guarantee one header per page of information.

-j

Print information associated with the following keywords: user, pid, ppid, pgid, sess, jobc, state, tt, time, and command.

-L

List the set of keywords available for the -O and -o options.

-l

Display information associated with the following keywords: uid, pid, ppid, flags, cpu, pri, nice, vsz=SZ, rss, wchan, state=S, paddr=ADDR, tty, time, and command=CMD.

-M

Print the threads corresponding to each task.

-m

Sort by memory usage, instead of the combination of controlling terminal and process ID.

-O

Add the information associated with the space or comma separated list of keywords specified, after the process ID, in the default information display. Keywords may be appended with an equals (‘=’) sign and a string. This causes the printed header to use the specified string instead of the standard header.

-o

Display information associated with the space or comma separated list of keywords specified. Multiple keywords may also be given in the form of more than one -o option. Keywords may be appended with an equals (‘=’) sign and a string. This causes the printed header to use the specified string instead of the standard header. If all keywords have empty header texts, no header line is written.

-p

Display information about processes which match the specified process IDs.

-r

Sort by current CPU usage, instead of the combination of controlling terminal and process ID.

-S

Change the way the process time is calculated by summing all exited children to their parent process.

-T

Display information about processes attached to the device associated with the standard input.

-t

Display information about processes attached to the specified terminal devices.

-U

Display the processes belonging to the specified real user IDs.

-u

Display the processes belonging to the specified usernames.

-v

Display information associated with the following keywords: pid, state, time, sl, re, pagein, vsz, rss, lim, tsiz, %cpu, %mem, and command. The -v option implies the -m option.

-w

Use 132 columns to display information, instead of the default which is your window size. If the -w option is specified more than once, ps will use as many columns as necessary without regard for your window size. When output is not to a terminal, an unlimited number of columns are always used.

-X

When displaying processes matched by other options, skip any processes which do not have a controlling terminal.

-x

When displaying processes matched by other options, include processes which do not have a controlling terminal. This is the opposite of the -X option. If both -X and -x are specified in the same command, then ps will use the one which was specified last.

A complete list of the available keywords is given below. Some of these keywords are further specified as follows:

%cpu

The CPU utilization of the process; this is a decaying average over up to a minute of previous (real) time. Because the time base over which this is computed varies (some processes may be very young), it is possible for the sum of all %cpu fields to exceed 100%.

%mem

The percentage of real memory used by this process.

flags

The flags associated with the process as in the include file ⟨sys/proc.h⟩:

P_ADVLOCK	0x00001	Process may hold a POSIX advisory lock
P_CONTROLT	0x00002	Has a controlling terminal
P_LP64	0x00004		Process is LP64
P_NOCLDSTOP	0x00008	No SIGCHLD when children stop
P_PPWAIT	0x00010	Parent is waiting for child to exec/exit
P_PROFIL	0x00020	Has started profiling
P_SELECT	0x00040	Selecting; wakeup/waiting danger
P_CONTINUED	0x00080	Process was stopped and continued
P_SUGID	0x00100		Had set id privileges since last exec
P_SYSTEM	0x00200	System proc: no sigs, stats or swapping
P_TIMEOUT	0x00400	Timing out during sleep
P_TRACED	0x00800	Debugged process being traced
P_WAITED	0x01000	Debugging process has waited for child
P_WEXIT	0x02000		Working on exiting
P_EXEC	0x04000		Process called exec
P_OWEUPC	0x08000	Owe process an addupc() call at next ast
P_WAITING	0x40000	Process has a wait() in progress
P_KDEBUG	0x80000 Kdebug tracing on for this process

lim

The soft limit on memory used, specified via a call to setrlimit(2).

lstart

The exact time the command started, using the ‘%c’ format described in strftime(3).

nice

The process scheduling increment (see setpriority(2)).

rss

the real memory (resident set) size of the process (in 1024 byte units).

start

The time the command started. If the command started less than 24 hours ago, the start time is displayed using the “%l:ps.1p” format described in strftime(3). If the command started less than 7 days ago, the start time is displayed using the “%a6.15p” format. Otherwise, the start time is displayed using the “%e%b%y” format.

state

The state is given by a sequence of characters, for example, “RWNA”. The first character indicates the run state of the process:

I

Marks a process that is idle (sleeping for longer than about 20 seconds).

R

Marks a runnable process.

S

Marks a process that is sleeping for less than about 20 seconds.

T

Marks a stopped process.

U

Marks a process in uninterruptible wait.

Z

Marks a dead process (a “zombie”).

Additional characters after these, if any, indicate additional state information:

+

The process is in the foreground process group of its control terminal.

<

The process has raised CPU scheduling priority.

>

The process has specified a soft limit on memory requirements and is currently exceeding that limit; such a process is (necessarily) not swapped.

A

the process has asked for random page replacement (VA_ANOM, from vadvise(2), for example, lisp(1) in a garbage collect).

E

The process is trying to exit.

L

The process has pages locked in core (for example, for raw I/O).

N

The process has reduced CPU scheduling priority (see setpriority(2)).

S

The process has asked for FIFO page replacement (VA_SEQL, from vadvise(2), for example, a large image processing program using virtual memory to sequentially address voluminous data).

s

The process is a session leader.

V

The process is suspended during a vfork(2).

W

The process is swapped out.

X

The process is being traced or debugged.

tt

An abbreviation for the pathname of the controlling terminal, if any. The abbreviation consists of the three letters following /dev/tty, or, for the console, “con”. This is followed by a ‘-’ if the process can no longer reach that controlling terminal (i.e., it has been revoked).

wchan

The event (an address in the system) on which a process waits. When printed numerically, the initial part of the address is trimmed off and the result is printed in hex, for example, 0x80324000 prints as 324000.

When printing using the command keyword, a process that has exited and has a parent that has not yet waited for the process (in other words, a zombie) is listed as “<defunct>”, and a process which is blocked while trying to exit is listed as “<exiting>”. If the arguments cannot be located (usually because it has not been set, as is the case of system processes and/or kernel threads) the command name is printed within square brackets. The process can change the arguments shown with setproctitle(3). Otherwise, ps makes an educated guess as to the file name and arguments given when the process was created by examining memory or the swap area. The method is inherently somewhat unreliable and in any event a process is entitled to destroy this information. The ucomm (accounting) keyword can, however, be depended on. If the arguments are unavailable or do not agree with the ucomm keyword, the value for the ucomm keyword is appended to the arguments in parentheses.

Keywords

The following is a complete list of the available keywords and their meanings. Several of them have aliases (keywords which are synonyms).

%cpu

percentage CPU usage (alias pcpu)

%mem

percentage memory usage (alias pmem)

acflag

accounting flag (alias acflg)

args

command and arguments

comm

command

command

command and arguments

cpu

short-term CPU usage factor (for scheduling)

etime

elapsed running time

flags

the process flags, in hexadecimal (alias f)

gid

processes group id (alias group)

inblk

total blocks read (alias inblock)

jobc

job control count

ktrace

tracing flags

ktracep

tracing vnode

lim

memoryuse limit

logname

login name of user who started the session

lstart

time started

majflt

total page faults

minflt

total page reclaims

msgrcv

total messages received (reads from pipes/sockets)

msgsnd

total messages sent (writes on pipes/sockets)

nice

nice value (alias ni)

nivcsw

total involuntary context switches

nsigs

total signals taken (alias nsignals)

nswap

total swaps in/out

nvcsw

total voluntary context switches

nwchan

wait channel (as an address)

oublk

total blocks written (alias oublock)

p_ru

resource usage (valid only for zombie)

paddr

swap address

pagein

pageins (same as majflt)

pgid

process group number

pid

process ID

ppid

parent process ID

pri

scheduling priority

prsna

persona

re

core residency time (in seconds; 127 = infinity)

rgid

real group ID

rss

resident set size

ruid

real user ID

ruser

user name (from ruid)

sess

session ID

sig

pending signals (alias pending)

sigmask

blocked signals (alias blocked)

sl

sleep time (in seconds; 127 = infinity)

start

time started

state

symbolic process state (alias stat)

svgid

saved gid from a setgid executable

svuid

saved UID from a setuid executable

tdev

control terminal device number

time

accumulated CPU time, user + system (alias cputime)

tpgid

control terminal process group ID

tsess

control terminal session ID

tsiz

text size (in Kbytes)

tt

control terminal name (two letter abbreviation)

tty

full name of control terminal

ucomm

name to be used for accounting

uid

effective user ID

upr

scheduling priority on return from system call (alias usrpri)

user

user name (from UID)

utime

user CPU time (alias putime)

vsz

virtual size in Kbytes (alias vsize)

wchan

wait channel (as a symbolic name)

wq

total number of workqueue threads

wqb

number of blocked workqueue threads

wqr

number of running workqueue threads

wql

workqueue limit status (C = constrained thread limit, T = total thread limit)

xstat

exit or stop status (valid only for stopped or zombie process)

Environment

The following environment variables affect the execution of ps:

COLUMNS

If set, specifies the user's preferred output width in column positions. By default, ps attempts to automatically determine the terminal width.

Files

/dev

special files and device names

/var/run/dev.db

/dev name database

/var/db/kvm_kernel.db

system namelist database

Legacy description

In legacy mode, ps functions as described above, with the following differences:

-e

Display the environment as well. Same as -E.

-g

Ignored for compatibility. Takes no argument.

-l

Display information associated with the following keywords: uid, pid, ppid, cpu, pri, nice, vsz, rss, wchan, state, tt, time, and command.

-u

Display information associated with the following keywords: user, pid, %cpu, %mem, vsz, rss, tt, state, start, time, and command. The -u option implies the -r option.

The biggest change is in the interpretation of the -u option, which now displays processes belonging to the specified username(s). Thus, "ps -aux" will fail (unless you want to know about user "x"). As a convenience, however, "ps aux" still works as it did in Tiger.

For more information about legacy mode, see compat(5).