PS(1) General Commands Manual PS(1)
ps - display process status
ps [-AaceHhjkLlmrSTuvwx] [-M core] [-N system] [-O fmt] [-o fmt] [-p pid]
[-t tty] [-U username] [-W swap]
The ps utility displays information about active processes. When given
no options, ps prints information about processes of the current user
that have a controlling terminal.
The information displayed is selected based on a set of keywords (and for
even more control, see the -L, -O, and -o options). The default output
format includes, for each process, the process's ID, controlling
terminal, state, CPU time (including both user and system time), and
The options are as follows:
-A Display information about processes for all users, including
those without controlling terminals.
-a Display information about processes for all users with
-c Do not display full command with arguments, but only the
executable name. This may be somewhat confusing; for example,
all sh(1) scripts will show as "sh".
-e Display the environment as well.
-H Also display information about kernel visible threads.
-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.
-k Also display information about kernel threads.
-L List the set of available keywords. This option should not be
specified with other options.
-l Display information associated with the following keywords: uid,
pid, ppid, cpu, pri, nice, vsz, rss, wchan, state, tt, time, and
Extract values associated with the name list from the specified
core instead of the running kernel.
-m Sort by memory usage, instead of by start time ID.
Extract the name list from the specified system instead of the
-O fmt 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 fmt Display information associated with the space or comma separated
list of keywords specified. 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.
-p pid Display information associated with the specified process ID.
-r Sort by current CPU usage, instead of by start time 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 tty Display information about processes attached to the specified
Display the processes belonging to the specified username.
-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.
-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.
When not using the running kernel, extract swap information from
the specified file.
-w Use 132 columns to display information, instead of the default,
which is the window size. If the -w option is specified more
than once, ps will use as many columns as necessary without
regard for window size.
-x Display information about processes without controlling
The following is a complete list of the available keywords and their
meanings. Several of them have aliases, which are also noted.
%cpu Alias: pcpu. The CPU utilization of the process; this is
a decaying average over up to a minute of previous (real)
time. Since the time base over which this is computed
varies (since processes may be very young) it is possible
for the sum of all %cpu fields to exceed 100%.
%mem Alias: pmem. The percentage of real memory used by this
acflag Alias: acflg. Accounting flag.
command Alias: args. Command and arguments.
cpu Short-term CPU usage factor (for scheduling).
cpuid CPU ID (zero on single processor systems).
cwd Current working directory.
dsiz Data size, in Kilobytes.
emul Name of system call emulation environment.
etime Elapsed time since the process was started.
flags Alias: f. The thread flags (in hexadecimal), as defined
in the include file <sys/proc.h>:
P_INKTR 0x1 writing ktrace(2) record
P_PROFPEND 0x2 this thread needs SIGPROF
P_ALRMPEND 0x4 this thread needs SIGVTALRM
P_SIGSUSPEND 0x8 need to restore before-suspend mask
P_CANTSLEEP 0x10 this thread is not permitted to sleep
P_SELECT 0x40 selecting; wakeup/waiting danger
P_SINTR 0x80 sleep is interruptible
P_SYSTEM 0x200 system process: no sigs, stats, or
P_TIMEOUT 0x400 timing out during sleep
P_WEXIT 0x2000 working on exiting
P_OWEUPC 0x8000 profiling sample needs recording
P_SUSPSINGLE 0x80000 need to suspend for single threading
P_CONTINUED 0x800000 thread has continued after a stop
P_THREAD 0x4000000 not the original thread
P_SUSPSIG 0x8000000 stopped because of a signal
P_SOFTDEP 0x10000000 stuck processing softdep worklist
P_CPUPEG 0x40000000 do not move to another cpu
gid Effective group.
group Text name of effective group ID.
inblk Alias: inblock. Total blocks read.
jobc Job control count.
ktrace Tracing flags.
ktracep Tracing vnode.
lim The soft limit on memory used, specified via a call to
logname Alias: login. Login name of user who started the
lstart The exact time the command started, using the "%c" format
described in strftime(3).
majflt Total page faults.
maxrss Maximum resident set size (in 1024 byte units).
minflt Total page reclaims.
msgrcv Total messages received (reads from pipes/sockets).
msgsnd Total messages sent (writes on pipes/sockets).
nice Alias: ni. The process scheduling increment (see
nivcsw Total involuntary context switches.
nsigs Alias: nsignals. Total signals taken.
nswap Total swaps in/out.
nvcsw Total voluntary context switches.
nwchan Wait channel (as an address).
oublk Alias: oublock. Total blocks written.
p_ru Resource usage (valid only for zombie processes).
paddr Swap address.
pagein Pageins (same as majflt).
pgid Process group number.
pid Process ID.
ppid Parent process ID.
pri Scheduling priority.
procflags The process flags (in hexadecimal), as defined in the
include file <sys/proc.h>:
PS_CONTROLT 0x1 process has a controlling
PS_EXEC 0x2 process called exec(3)
PS_INEXEC 0x4 process is doing an exec right
PS_EXITING 0x8 process is exiting
PS_SUGID 0x10 process had set ID privileges
since last exec
PS_SUGIDEXEC 0x20 last exec(3) was set[ug]id
PS_PPWAIT 0x40 parent is waiting for process
PS_ISPWAIT 0x80 process is parent of PPWAIT
PS_PROFIL 0x100 process has started profiling
PS_TRACED 0x200 process is being traced
PS_WAITED 0x400 debugging process has waited
PS_COREDUMP 0x800 busy coredumping
PS_SINGLEEXIT 0x1000 other threads must die
PS_SINGLEUNWIND 0x2000 other threads must unwind
PS_NOZOMBIE 0x4000 pid 1 waits for me instead of
PS_STOPPED 0x8000 just stopped, need to send
PS_SYSTEM 0x10000 No signals, stats or swapping
PS_EMBRYO 0x20000 New process, not yet fledged
PS_ZOMBIE 0x40000 Dead and ready to be waited for
PS_NOBROADCASTKILL 0x80000 Process excluded from kill -1
PS_PLEDGE 0x100000 process has called pledge(2)
re Core residency time (in seconds; 127 = infinity).
rgid Real group ID.
rgroup Text name of real group ID.
rlink Reverse link on run queue, or 0.
rss The real memory (resident set) size of the process (in
1024 byte units).
rsz Alias: rssize. Resident set size + (text size / text use
rtable Routing table.
ruid Real user ID.
ruser User name (from ruid).
sess Session pointer.
sig Alias: pending. Pending signals.
sigcatch Alias: caught. Caught signals.
sigignore Alias: ignored. Ignored signals.
sigmask Alias: blocked. Blocked signals.
sl Sleep time (in seconds; 127 = infinity).
ssiz Stack size, in Kilobytes.
start The time the command started. If the command started
less than 24 hours ago, the start time is displayed using
the "%l:%M%p" format described in strftime(3). If the
command started less than 7 days ago, the start time is
displayed using the "%a%I%p" format. Otherwise, the
start time is displayed using the "%e%b%y" format.
state Alias: stat. The state is given by a sequence of
letters, for example, "RWN". The first letter indicates
the run state of the process:
D Marks a process in disk (or other short term,
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.
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 a 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
E The process is trying to exit.
K The process is a kernel thread.
N The process has a reduced CPU scheduling
p The process has called pledge(2).
s The process is a session leader.
V The process is suspended during a vfork(2).
X The process is being traced or debugged.
/n On multiprocessor machines, specifies processor
svgid Saved GID from a setgid executable.
svuid Saved UID from a setuid executable.
tdev Control terminal device number.
tid Thread ID. Used together with -H.
time Alias: cputime. Accumulated CPU time, user + system.
tpgid Control terminal process group ID.
tsess Control terminal session pointer.
tsiz Text size, in Kilobytes.
tt An abbreviation for the pathname of the controlling
terminal, if any. The abbreviation consists of the two
letters following "/dev/tty", or, for the console, "co".
This is followed by a `-' if the process can no longer
reach that controlling terminal (i.e. it has been
tty Full name of control terminal.
ucomm Alias: comm. Name to be used for accounting.
uid Effective user ID.
upr Alias: usrpri. Scheduling priority on return from system
user User name (from uid).
vsz Alias: vsize. Virtual size, in Kilobytes.
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.
xstat Exit or stop status (valid only for stopped or zombie
The following environment variables affect the execution of ps:
COLUMNS If set to a positive integer, output is formatted to the given
width in columns. Otherwise, ps defaults to the terminal width
minus 1. If none of stdout, stderr, and stdin are a terminal,
79 columns are used.
LC_CTYPE The character encoding locale(1). It decides which byte
sequences form characters, which characters are printable, and
what their display width is. If unset or set to "C", "POSIX",
or an unsupported value, only printable ASCII characters are
printed. Tabs, newlines, non-printable ASCII characters, and
non-ASCII bytes are encoded with vis(3). If UTF-8 output is
enabled, valid characters that are not printable are replaced
with the Unicode replacement character U+FFFD. These rules for
example apply to command names, arguments, and environments and
to directory, user, and group names.
TZ The time zone to use when displaying dates. See environ(7) for
/dev special files and device names
/var/db/kvm_bsd.db system namelist database
/var/run/dev.db /dev name database
The ps utility exits 0 on success, and >0 if an error occurs.
Display information on all system processes:
$ ps -auxw
fstat(1), kill(1), netstat(1), pgrep(1), pkill(1), procmap(1), systat(1),
top(1), w(1), kvm(3), strftime(3), dev_mkdb(8), iostat(8), pstat(8),
The ps utility is compliant with the IEEE Std 1003.1-2008 ("POSIX.1")
specification, except that the flag [-G] is unsupported and the flags
[-ptU] support only single arguments, not lists.
The flags [-defglnu] are marked by IEEE Std 1003.1-2008 ("POSIX.1") as
being an X/Open System Interfaces option. Of these, [-dfgn] are not
supported by this implementation of ps; behaviour for the flags [-elu]
differs between this implementation and the X/Open System Interfaces
option of IEEE Std 1003.1-2008 ("POSIX.1").
The flags [-cHhjkLMmNOrSTvWwx] are extensions to IEEE Std 1003.1-2008
Only the following keywords are recognised by IEEE Std 1003.1-2008
("POSIX.1"): args, comm, etime, group, nice, pcpu, pgid, pid, ppid,
rgroup, ruser, time, tty, user, and vsz.
A ps command appeared in Version 3 AT&T UNIX in section 8 of the manual.
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>". 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, so the names cannot be depended on too much. The ucomm
(accounting) keyword can, however, be depended on.
The information displayed is only a snapshot of a constantly changing
OpenBSD 6.2 October 26, 2016 OpenBSD 6.2
[Unix Hosting |
[Engineering & Automation |
Software Development |