PS(1) BSD General Commands Manual PS(1)
ps -- process status
ps [-AaCcehjlmrSsTuvwx] [-k key] [-M core] [-N system] [-O fmt] [-o fmt] [-p pid] [-t tty] [-U username] [-W swap]
ps displays a header line followed by lines containing information about running processes. By default, the display includes only processes
that have controlling terminals and are owned by your uid. The default sort order of controlling terminal and (among processes with the same
controlling terminal) process ID may be changed using the -k, -m, or -r options.
The information displayed for each process is selected based on a set of keywords (see the -L, -O, and -o options). The default output for-
mat includes, for each process, the process' ID, controlling terminal, CPU time (including both user and system time), state, and associated
The options are as follows:
-A Display information about all processes. This is equivalent to -a -x.
-a Display information about other users' processes as well as your own. Note that this does not display information about processes
without controlling terminals.
-C Change the way the CPU percentage is calculated by using a ``raw'' CPU calculation that ignores ``resident'' time (this normally has
-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. The environment for other users' processes can only be displayed by the super-user.
-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 Sort the output using the space or comma separated list of keywords. Multiple sort keys may be specified, using any of the -k, -m,
or -r options. The default sort order is equivalent to -k tdev,pid.
-L List the set of available keywords.
-l Display information associated with the following keywords: uid, pid, ppid, cpu, pri, nice, vsz, rss, wchan, state, tt, time, and
-M Extract values from the specified core file instead of the running system.
-m Sort by memory usage, equivalent to -k vsz.
-N Extract the name list from the specified system instead of the default ``/netbsd''. Ignored unless -M is specified.
-O Display information associated with the space or comma separated list of keywords specified. The -O option does not suppress the
default display; it inserts additional keywords just after the pid keyword in the default display, or after the pid keyword (if any)
in a non-default display specified before the first use of the -O flag. Keywords inserted by multiple -O options will be adjacent.
An equals sign (``='') followed by a customised header string may be appended to a keyword, as described in more detail under the -o
-o Display information associated with the space or comma separated list of keywords specified. Use of the -o option suppresses the set
of keywords that would be displayed by default, or appends to the set of keywords specified by other options.
An equals sign (``='') followed by a customised header string may be appended to a keyword. This causes the printed header to use
the specified string instead of the default header associated with the keyword.
Everything after the first equals sign is part of the customised header text, and this may include embedded spaces (`` ''), commas
(``,''), or equals signs (``=''). To specify multiple keywords with customised headers, use multiple -o or -O options.
If all the keywords to be displayed have customised headers, and all the customised headers are entirely empty, then the header line
is not printed at all.
-p Display information associated with the specified process ID.
-r Sort by current CPU usage. This is equivalent to -k %cpu.
-S Change the way the process time is calculated by summing all exited children to their parent process.
-s Display one line for each LWP, rather than one line for each process, and display information associated with the following keywords:
uid, pid, ppid, cpu, lid, nlwp, pri, nice, vsz, rss, wchan, lstate, tt, time, and command.
-T Display information about processes attached to the device associated with the standard input.
-t Display information about processes attached to the specified terminal device. Use a question mark (``?'') for processes not
attached to a terminal device and a minus sign (``-'') for processes that have been revoked from their terminal device.
-U Displays processes belonging to the user whose username or uid has been given to the -U switch.
-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.
-W Extract swap information from the specified file instead of the default ``/dev/drum''. Ignored unless -M is specified.
-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 to your window size.
-x Also display information about processes without controlling terminals.
A complete list of the available keywords are listed 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. 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 The percentage of real memory used by this process.
flags The flags (in hexadecimal) associated with the process as in the include file <sys/proc.h>:
P_ADVLOCK 0x00000001 process may hold a POSIX advisory lock
P_CONTROLT 0x00000002 process has a controlling terminal
P_NOCLDSTOP 0x00000008 no SIGCHLD when children stop
P_PPWAIT 0x00000010 parent is waiting for child to exec/exit
P_PROFIL 0x00000020 process has started profiling
P_SELECT 0x00000040 selecting; wakeup/waiting danger
P_SINTR 0x00000080 sleep is interruptible
P_SUGID 0x00000100 process had set id privileges since last exec
P_SYSTEM 0x00000200 system process: no sigs or stats
P_TIMEOUT 0x00000400 timing out during sleep
P_TRACED 0x00000800 process is being traced
P_WAITED 0x00001000 debugging process has waited for child
P_WEXIT 0x00002000 working on exiting
P_EXEC 0x00004000 process called execve(2)
P_OWEUPC 0x00008000 owe process an addupc() call at next ast
P_FSTRACE 0x00010000 tracing via file system
P_NOCLDWAIT 0x00020000 no zombies when children die
P_32 0x00040000 32-bit process (used on 64-bit kernels)
P_BIGLOCK 0x00080000 process needs kernel ``big lock'' to run
P_INEXEC 0x00100000 process is exec'ing and cannot be traced
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:%M%p'' for-
mat described in strftime(3). If the command started less than 7 days ago, the start time is displayed using the ``%a%p'' format.
Otherwise, the start time is displayed using the ``%e%b%y'' format.
state The state is given by a sequence of letters, for example, ``RWNA''. The first letter indicates the run state of the process:
D Marks a process in disk (or other short term, uninterruptible) wait.
I Marks a process that is idle (sleeping for longer than about 20 seconds).
O Marks a process running on a processor.
R Marks a runnable process, or one that is in the process of creation.
S Marks a process that is sleeping for less than about 20 seconds.
T Marks a stopped process.
U Marks a suspended 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 LWP is detached (can't be waited for).
< The process has raised CPU scheduling priority.
a The process is using scheduler activations.
E The process is trying to exit.
K The process is a kernel thread or system process.
l The process has multiple LWPs.
N The process has reduced CPU scheduling priority (see setpriority(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.
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 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>''.
ps will try to locate the processes' argument vector from the user area in order to print the command name and arguments. This method is not
reliable because a process is allowed to destroy this information. The ucomm (accounting) keyword will always contain the real command name
as contained in the process structure's p_comm field.
If the command vector 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.
To indicate that the argument vector has been tampered with, ps will append the real command name to the output within parentheses if the
basename of the first argument in the argument vector does not match the contents of the real command name.
In addition, ps checks for the following two situations and does not append the real command name parenthesized:
The login process traditionally adds a '-' in front of the shell name to indicate a login shell. ps will not append parenthesized
the command name if it matches with the name in the first argument of the argument vector, skipping the leading '-'.
Daemon processes frequently report their current activity by setting their name to be like ``daemonname: current-activity''. ps will
not append parenthesized the command name, if the string preceding the ':' in the first argument of the argument vector matches the
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)
comm command (the argv value)
command command and arguments (alias args)
cpu short-term CPU usage factor (for scheduling)
cpuid CPU number the current process or lwp is running on.
ctime accumulated CPU time of all children that have exited
egid effective group id
egroup group name (from egid)
emul emulation name
etime elapsed time since the process was started, in the form [[dd-]hh:]mm:ss
euid effective user id
euser user name (from euid)
flags the process flags, in hexadecimal (alias f)
gid effective group id
group group name (from gid)
groupnames group names (from group access list)
groups group access list
inblk total blocks read (alias inblock)
jobc job control count
ktrace tracing flags
ktracep tracing vnode
laddr kernel virtual address of the struct lwp belonging to the LWP.
lid ID of the LWP
lim memory use limit
lname descriptive name of the LWP
logname login name of user who started the process (alias login)
lstart time started
lstate symbolic LWP state
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
nlwp number of LWPs in the process
nsigs total signals taken (alias nsignals)
nvcsw total voluntary context switches
nwchan wait channel (as an address)
oublk total blocks written (alias oublock)
p_ru resource usage pointer (valid only for zombie)
paddr kernel virtual address of the struct proc belonging to the process.
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
rlink reverse link on run queue, or 0
rlwp Number of LWPs on a processor or run queue
rss resident set size
rsz resident set size + (text size / text use count) (alias rssize)
ruid real user ID
ruser user name (from ruid)
sess session pointer
sid session ID
sig pending signals (alias pending)
sigcatch caught signals (alias caught)
sigignore ignored signals (alias ignored)
sigmask blocked signals (alias blocked)
sl sleep time (in seconds; 127 = infinity)
start time started
state symbolic process state (alias stat)
stime accumulated system CPU time
svgid saved gid from a setgid executable
svgroup group name (from svgid)
svuid saved uid from a setuid executable
svuser user name (from svuid)
tdev control terminal device number
time accumulated CPU time, user + system (alias cputime)
tpgid control terminal process group ID
tsess control terminal session pointer
tsiz text size (in Kbytes)
tt control terminal name (two letter abbreviation)
tty full name of control terminal
uaddr kernel virtual address of the struct user belonging to the LWP.
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 accumulated user CPU time
vsz virtual size in Kbytes (alias vsize)
wchan wait channel (as a symbolic name)
xstat exit or stop status (valid only for stopped or zombie process)
/dev special files and device names
/dev/drum default swap device
/dev name database
/var/db/kvm.db system namelist database
/netbsd default system namelist
kill(1), pgrep(1), pkill(1), sh(1), w(1), kvm(3), strftime(3), dev_mkdb(8), pstat(8)
Since ps cannot run faster than the system and is run as any other scheduled process, the information it displays can never be exact.
October 22, 2009 BSD