DESCRIPTION
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 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 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 no effect).
-
-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 command.
-
-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 option.
-
-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” 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 “%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:
-
-shellname
-
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 ‘-'.
-
daemonname: current-activity
-
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 command name.