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PS(1) NetBSD General Commands Manual PS(1)
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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 control-
ling 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 format
includes, for each process, the process' ID, controlling terminal, CPU
time (including both user and system time), state, and associated com-
The options are as follows:
-A Display information about all processes. This is equivalent to
-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 nor-
mally has no effect).
-c Do not display full command with arguments, but only the exe-
cutable 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 key-
words. Multiple sort keys may be specified, using any of the -k,
-m, or -r options. The default sort order is equivalent to -k
-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 run-
-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
An equals sign (``='') followed by a customised header string may
be appended to a keyword, as described in more detail under the
-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 asso-
ciated with the standard input.
-t Display information about processes attached to the specified
terminal device. Use an question mark (``?'') for processes not
attached to a terminal device and a minus sign (``-'') for pro-
cesses 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 for your window size.
-x Also display information about processes without controlling ter-
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
%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
P_CONTROLT 0x00000002 process has a controlling terminal
P_INMEM 0x00000004 process is loaded into memory
P_NOCLDSTOP 0x00000008 no SIGCHLD when children stop
P_PPWAIT 0x00000010 parent is waiting for child to
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
P_SYSTEM 0x00000200 system process: no sigs, stats or
P_TIMEOUT 0x00000400 timing out during sleep
P_TRACED 0x00000800 process is being traced
P_WAITED 0x00001000 debugging process has waited for
P_WEXIT 0x00002000 working on exiting
P_EXEC 0x00004000 process called execve(2)
P_OWEUPC 0x00008000 owe process an addupc() call at
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
P_BIGLOCK 0x00080000 process needs kernel ``big lock''
P_INEXEC 0x00100000 process is exec'ing and cannot be
P_SYSTRACE 0x00200000 process system call tracing active
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:%M%p''
format 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
state The state is given by a sequence of letters, for example,
``RWNA''. The first letter indicates the run state of the
D Marks a process in disk (or other short term, uninter-
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
S Marks a process that is sleeping for less than about 20
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
+ The process is in the foreground process group of its
- 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 pages locked in core (for example, for
l The process has multiple LWPs.
N The process has reduced CPU scheduling priority (see
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 two letters following
``/dev/tty'', or, for the console, ``co''. This is followed by a
``-'' if the process can no longer reach that controlling termi-
nal (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 com-
mand 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 argu-
ment of the argument vector, skipping the leading `-'.
Daemon processes frequently report their current activity by set-
ting 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 command name.
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
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
holdcnt number of holds on the process (if non-zero, process can't be
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
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)
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 pointer (valid only for zombie)
paddr kernel virtual address of the struct proc belonging to the
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
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
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
/dev special files and device names
/dev/drum default swap device
/var/run/dev.db /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),
Since ps cannot run faster than the system and is run as any other sched-
uled process, the information it displays can never be exact.
NetBSD 5.0.1 October 18, 2008 NetBSD 5.0.1