PS(1) General Commands Manual PS(1)
ps – process status
ps [-AaCcEefhjlMmrSTvwXx] [-O fmt | -o fmt] [-G gid[,gid...]]
[-g grp[,grp...]] [-u uid[,uid...]] [-p pid[,pid...]] [-t tty[,tty...]]
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
-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
-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
-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
-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
%mem The percentage of real memory used by this process.
flags The flags associated with the process as in the include file
P_ADVLOCK 0x00001 Process may hold a POSIX
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
P_PROFIL 0x00020 Has started profiling
P_SELECT 0x00040 Selecting; wakeup/waiting danger
P_CONTINUED 0x00080 Process was stopped and
P_SUGID 0x00100 Had set id privileges since last
P_SYSTEM 0x00200 System proc: no sigs, stats or
P_TIMEOUT 0x00400 Timing out during sleep
P_TRACED 0x00800 Debugged process being traced
P_WAITED 0x01000 Debugging process has waited for
P_WEXIT 0x02000 Working on exiting
P_EXEC 0x04000 Process called exec
P_OWEUPC 0x08000 Owe process an addupc() call at
P_WAITING 0x40000 Process has a wait() in progress
P_KDEBUG 0x80000 Kdebug tracing on for this
lim The soft limit on memory used, specified via a call to
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
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
state The state is given by a sequence of characters, for example,
“RWNA”. The first character indicates the run state of the
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
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
+ The process is in the foreground process group of its
< 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
E The process is trying to exit.
L The process has pages locked in core (for example, for
N The process has reduced CPU scheduling priority (see
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
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
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
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
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
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
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.
/dev special files and device names
/var/run/dev.db /dev name database
/var/db/kvm_kernel.db system namelist database
In legacy mode, ps functions as described above, with the following
-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
-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).
kill(1), w(1), kvm(3), strftime(3), sysctl(8)
The ps utility supports the Version 3 of the Single UNIX Specification
The ps command appeared in Version 4 AT&T UNIX.
Since ps cannot run faster than the system and is run as any other
scheduled process, the information it displays can never be exact.
The ps utility does not correctly display argument lists containing
macOS 12.1 March 20, 2005 macOS 12.1