ps man page

The contents of this page come from the CentOS Linux ps man page, i.e., the man page for the Linux ps command (also known as the help page for the ps command).

Linux ps man page (Linux ps command help)

PS(1)			      Linux User’s Manual			 PS(1)



NAME
ps - report a snapshot of the current processes.

SYNOPSIS
ps [options]



DESCRIPTION
ps displays information about a selection of the active processes. If you want
a repetitive update of the selection and the displayed information, use top(1)
instead.

This version of ps accepts several kinds of options:
1   UNIX options, which may be grouped and must be preceded by a dash.
2   BSD options, which may be grouped and must not be used with a dash.
3   GNU long options, which are preceded by two dashes.

Options of different types may be freely mixed, but conflicts can appear.
There are some synonymous options, which are functionally identical, due to
the many standards and ps implementations that this ps is compatible with.

Note that "ps -aux" is distinct from "ps aux". The POSIX and UNIX standards
require that "ps -aux" print all processes owned by a user named "x", as well
as printing all processes that would be selected by the -a option. If the user
named "x" does not exist, this ps may interpret the command as "ps aux"
instead and print a warning. This behavior is intended to aid in transitioning
old scripts and habits. It is fragile, subject to change, and thus should not
be relied upon.

By default, ps selects all processes with the same effective user ID
(euid=EUID) as the current user and associated with the same terminal as the
invoker. It displays the process ID (pid=PID), the terminal associated with
the process (tname=TTY), the cumulated CPU time in [dd-]hh:mm:ss format
(time=TIME), and the executable name (ucmd=CMD). Output is unsorted by
default.

The use of BSD-style options will add process state (stat=STAT) to the default
display and show the command args (args=COMMAND) instead of the executable
name. You can override this with the PS_FORMAT environment variable. The use
of BSD-style options will also change the process selection to include
processes on other terminals (TTYs) that are owned by you; alternately, this
may be described as setting the selection to be the set of all processes
filtered to exclude processes owned by other users or not on a terminal. These
effects are not considered when options are described as being "identical"
below, so -M will be considered identical to Z and so on.

Except as described below, process selection options are additive. The default
selection is discarded, and then the selected processes are added to the set
of processes to be displayed. A process will thus be shown if it meets any of
the given selection criteria.


EXAMPLES
To see every process on the system using standard syntax:
   ps -e
   ps -ef
   ps -eF
   ps -ely

To see every process on the system using BSD syntax:
   ps ax
   ps axu

To print a process tree:
   ps -ejH
   ps axjf

To get info about threads:
   ps -eLf
   ps axms

To get security info:
   ps -eo euser,ruser,suser,fuser,f,comm,label
   ps axZ
   ps -eM

To see every process running as root (real & effective ID) in user format:
   ps -U root -u root u

To see every process with a user-defined format:
   ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
   ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
   ps -eopid,tt,user,fname,tmout,f,wchan

Print only the process IDs of syslogd:
   ps -C syslogd -o pid=

Print only the name of PID 42:
   ps -p 42 -o comm=



SIMPLE PROCESS SELECTION
-A		Select all processes. Identical to -e.


-N		Select all processes except those that fulfill the specified
		conditions. (negates the selection) Identical to --deselect.


T		Select all processes associated with this terminal. Identical
		to the t option without any argument.


-a		Select all processes except session leaders (see getsid(2))
		and processes not associated with a terminal.


a		Lift the BSD-style "only yourself" restriction, which is
		imposed upon the set of all processes when some BSD-style
		(without "-") options are used or when the ps personality
		setting is BSD-like. The set of processes selected in this
		manner is in addition to the set of processes selected by
		other means. An alternate description is that this option
		causes ps to list all processes with a terminal (tty), or to
		list all processes when used together with the x option.


-d		Select all processes except session leaders.


-e		Select all processes. Identical to -A.


g		Really all, even session leaders. This flag is obsolete and
		may be discontinued in a future release. It is normally
		implied by the a flag, and is only useful when operating in
		the sunos4 personality.


r		Restrict the selection to only running processes.


x		Lift the BSD-style "must have a tty" restriction, which is
		imposed upon the set of all processes when some BSD-style
		(without "-") options are used or when the ps personality
		setting is BSD-like. The set of processes selected in this
		manner is in addition to the set of processes selected by
		other means. An alternate description is that this option
		causes ps to list all processes owned by you (same EUID as
		ps), or to list all processes when used together with the a
		option.


--deselect	Select all processes except those that fulfill the specified
		conditions. (negates the selection) Identical to -N.



PROCESS SELECTION BY LIST
These options accept a single argument in the form of a blank-separated or
comma-separated list. They can be used multiple times.
For example: ps -p "1 2" -p 3,4


-C cmdlist	Select by command name.
		This selects the processes whose executable name is given in
		cmdlist.


-G grplist	Select by real group ID (RGID) or name.
		This selects the processes whose real group name or ID is in
		the grplist list. The real group ID identifies the group of
		the user who created the process, see getgid(2).


U userlist	Select by effective user ID (EUID) or name.
		This selects the processes whose effective user name or ID is
		in userlist. The effective user ID describes the user whose
		file access permissions are used by the process
		(see geteuid(2)). Identical to -u and --user.


-U userlist	select by real user ID (RUID) or name.
		It selects the processes whose real user name or ID is in the
		userlist list. The real user ID identifies the user who
		created the process, see getuid(2).


-g grplist	Select by session OR by effective group name.
		Selection by session is specified by many standards, but
		selection by effective group is the logical behavior that
		several other operating systems use. This ps will select by
		session when the list is completely numeric (as sessions are).
		Group ID numbers will work only when some group names are also
		specified. See the -s and --group options.


p pidlist	Select by process ID. Identical to -p and --pid.


-p pidlist	Select by PID.
		This selects the processes whose process ID numbers appear in
		pidlist. Identical to p and --pid.


-s sesslist	Select by session ID.
		This selects the processes with a session ID specified
		in sesslist.


t ttylist	Select by tty. Nearly identical to -t and --tty, but can also
		be used with an empty ttylist to indicate the terminal
		associated with ps. Using the T option is considered cleaner
		than using T with an empty ttylist.


-t ttylist	Select by tty.
		This selects the processes associated with the terminals given
		in ttylist. Terminals (ttys, or screens for text output) can
		be specified in several forms: /dev/ttyS1, ttyS1, S1. A plain
		"-" may be used to select processes not attached to any
		terminal.


-u userlist	Select by effective user ID (EUID) or name.
		This selects the processes whose effective user name or ID is
		in userlist. The effective user ID describes the user whose
		file access permissions are used by the process
		(see geteuid(2)). Identical to U and --user.


--Group grplist Select by real group ID (RGID) or name. Identical to -G.


--User userlist Select by real user ID (RUID) or name. Identical to -U.


--group grplist Select by effective group ID (EGID) or name.
		This selects the processes whose effective group name or ID is
		in grouplist. The effective group ID describes the group whose
		file access permissions are used by the process
		(see geteuid(2)). The -g option is often an alternative
		to --group.


--pid pidlist	Select by process ID. Identical to -p and p.


--ppid pidlist	Select by parent process ID. This selects the processes with a
		parent process ID in pidlist. That is, it selects processes
		that are children of those listed in pidlist.


--sid sesslist	Select by session ID. Identical to -s.


--tty ttylist	Select by terminal. Identical to -t and t.


--user userlist Select by effective user ID (EUID) or name. Identical to -u
		and U.


-123		Identical to --sid 123.


123		Identical to --pid 123.



OUTPUT FORMAT CONTROL
These options are used to choose the information displayed by ps. The output
may differ by personality.



-F		extra full format. See the -f option, which -F implies.


-O format	is like -o, but preloaded with some default columns. Identical
		to -o pid,format,state,tname,time,command or
		-o pid,format,tname,time,cmd, see -o below.


O format	is preloaded o (overloaded).
		The BSD O option can act like -O (user-defined output format
		with some common fields predefined) or can be used to specify
		sort order. Heuristics are used to determine the behavior of
		this option. To ensure that the desired behavior is obtained
		(sorting or formatting), specify the option in some other way
		(e.g. with -O or --sort). When used as a formatting option, it
		is identical to -O, with the BSD personality.


-M		Add a column of security data. Identical to Z. (for SE Linux)


X		Register format.


Z		Add a column of security data. Identical to -M. (for SE Linux)


-c		Show different scheduler information for the -l option.


-f		does full-format listing. This option can be combined with
		many other UNIX-style options to add additional columns. It
		also causes the command arguments to be printed. When used
		with -L, the NLWP (number of threads) and LWP (thread ID)
		columns will be added. See the c option, the format keyword
		args, and the format keyword comm.


j		BSD job control format.


-j		jobs format


l		display BSD long format.


-l		long format. The -y option is often useful with this.


o format	specify user-defined format. Identical to -o and --format.


-o format	user-defined format.
		format is a single argument in the form of a blank-separated
		or comma-separated list, which offers a way to specify
		individual output columns. The recognized keywords are
		described in the STANDARD FORMAT SPECIFIERS section below.
		Headers may be renamed
		(ps -o pid,ruser=RealUser -o comm=Command) as desired. If all
		column headers are empty (ps -o pid= -o comm=) then the header
		line will not be output. Column width will increase as needed
		for wide headers; this may be used to widen up columns such as
		WCHAN (ps -o pid,wchan=WIDE-WCHAN-COLUMN -o comm). Explicit
		width control (ps opid,wchan:42,cmd) is offered too. The
		behavior of ps -o pid=X,comm=Y varies with personality; output
		may be one column named "X,comm=Y" or two columns named "X"
		and "Y". Use multiple -o options when in doubt. Use the
		PS_FORMAT environment variable to specify a default as
		desired; DefSysV and DefBSD are macros that may be used to
		choose the default UNIX or BSD columns.


s		display signal format


u		display user-oriented format


v		display virtual memory format


-y		Do not show flags; show rss in place of addr. This option can
		only be used with -l.


-Z		display security context format (SELinux, etc.)


--format format user-defined format. Identical to -o and o.


--context	Display security context format. (for SE Linux)



OUTPUT MODIFIERS
-H		show process hierarchy (forest)


N namelist	Specify namelist file. Identical to -n, see -n above.


O order		Sorting order. (overloaded)
		The BSD O option can act like -O (user-defined output format
		with some common fields predefined) or can be used to specify
		sort order. Heuristics are used to determine the behavior of
		this option. To ensure that the desired behavior is obtained
		(sorting or formatting), specify the option in some other way
		(e.g. with -O or --sort).

		For sorting, obsolete BSD O option syntax is
		O[+|-]k1[,[+|-]k2[,...]]. It orders the processes listing
		according to the multilevel sort specified by the sequence of
		one-letter short keys k1, k2, ... described in the OBSOLETE
		SORT KEYS section below. The "+" is currently optional, merely
		re-iterating the default direction on a key, but may help to
		distinguish an O sort from an O format. The "-" reverses
		direction only on the key it precedes.


S		Sum up some information, such as CPU usage, from dead child
		processes into their parent. This is useful for examining a
		system where a parent process repeatedly forks off short-lived
		children to do work.


c		Show the true command name. This is derived from the name of
		the executable file, rather than from the argv value. Command
		arguments and any modifications to them (see setproctitle(3))
		are thus not shown. This option effectively turns the args
		format keyword into the comm format keyword; it is useful with
		the -f format option and with the various BSD-style format
		options, which all normally display the command arguments. See
		the -f option, the format keyword args, and the format keyword
		comm.


e		Show the environment after the command.


f		ASCII-art process hierarchy (forest)


h		No header. (or, one header per screen in the BSD personality)
		The h option is problematic. Standard BSD ps uses this option
		to print a header on each page of output, but older Linux ps
		uses this option to totally disable the header. This version
		of ps follows the Linux usage of not printing the header
		unless the BSD personality has been selected, in which case it
		prints a header on each page of output. Regardless of the
		current personality, you can use the long options --headers
		and --no-headers to enable printing headers each page or
		disable headers entirely, respectively.


k spec		specify sorting order. Sorting syntax is
		[+|-]key[,[+|-]key[,...]] Choose a multi-letter key from the
		STANDARD FORMAT SPECIFIERS section. The "+" is optional since
		default direction is increasing numerical or lexicographic
		order. Identical to --sort. Examples:
		ps jaxkuid,-ppid,+pid
		ps axk comm o comm,args
		ps kstart_time -ef


-n namelist	set namelist file. Identical to N.
		The namelist file is needed for a proper WCHAN display, and
		must match the current Linux kernel exactly for correct
		output. Without this option, the default search path for the
		namelist is:

		     $PS_SYSMAP
		     $PS_SYSTEM_MAP
		     /proc/*/wchan
		     /boot/System.map-`uname -r`
		     /boot/System.map
		     /lib/modules/`uname -r`/System.map
		     /usr/src/linux/System.map
		     /System.map


n		Numeric output for WCHAN and USER. (including all types of UID
		and GID)


-w		Wide output. Use this option twice for unlimited width.


w		Wide output. Use this option twice for unlimited width.


--cols n	set screen width


--columns n	set screen width


--cumulative	include some dead child process data (as a sum with the
		parent)


--forest	ASCII art process tree


--headers	repeat header lines, one per page of output


--no-headers	print no header line at all


--lines n	set screen height


--rows n	set screen height


--sort spec	specify sorting order. Sorting syntax is
		[+|-]key[,[+|-]key[,...]] Choose a multi-letter key from the
		STANDARD FORMAT SPECIFIERS section. The "+" is optional since
		default direction is increasing numerical or lexicographic
		order. Identical to k. For example:
		ps jax --sort=uid,-ppid,+pid


--width n	set screen width



THREAD DISPLAY
H		Show threads as if they were processes

-L		Show threads, possibly with LWP and NLWP columns

-T		Show threads, possibly with SPID column

m		Show threads after processes

-m		Show threads after processes



OTHER INFORMATION
L		List all format specifiers.

-V		Print the procps version.

V		Print the procps version.

--help		Print a help message.

--info		Print debugging info.

--version	Print the procps version.



NOTES
This ps works by reading the virtual files in /proc. This ps does not need to
be setuid kmem or have any privileges to run. Do not give this ps any special
permissions.

This ps needs access to namelist data for proper WCHAN display. For kernels
prior to 2.6, the System.map file must be installed.

CPU usage is currently expressed as the percentage of time spent running
during the entire lifetime of a process. This is not ideal, and it does not
conform to the standards that ps otherwise conforms to. CPU usage is unlikely
to add up to exactly 100%.

The SIZE and RSS fields don’t count some parts of a process including the page
tables, kernel stack, struct thread_info, and struct task_struct. This is
usually at least 20 KiB of memory that is always resident. SIZE is the virtual
size of the process (code+data+stack).

Processes marked <defunct> are dead processes (so-called "zombies") that
remain because their parent has not destroyed them properly. These processes
will be destroyed by init(8) if the parent process exits.



PROCESS FLAGS
The sum of these values is displayed in the "F" column, which is provided by
the flags output specifier.
1    forked but didn’t exec
4    used super-user privileges


PROCESS STATE CODES
Here are the different values that the s, stat and state output specifiers
(header "STAT" or "S") will display to describe the state of a process.
D    Uninterruptible sleep (usually IO)
R    Running or runnable (on run queue)
S    Interruptible sleep (waiting for an event to complete)
T    Stopped, either by a job control signal or because it is being traced.
W    paging (not valid since the 2.6.xx kernel)
X    dead (should never be seen)
Z    Defunct ("zombie") process, terminated but not reaped by its parent.

For BSD formats and when the stat keyword is used, additional characters may
be displayed:
<    high-priority (not nice to other users)
N    low-priority (nice to other users)
L    has pages locked into memory (for real-time and custom IO)
s    is a session leader
l    is multi-threaded (using CLONE_THREAD, like NPTL pthreads do)
+    is in the foreground process group



OBSOLETE SORT KEYS
These keys are used by the BSD O option (when it is used for sorting). The GNU
--sort option doesn’t use these keys, but the specifiers described below in
the STANDARD FORMAT SPECIFIERS section. Note that the values used in sorting
are the internal values ps uses and not the "cooked" values used in some of
the output format fields (e.g. sorting on tty will sort into device number,
not according to the terminal name displayed). Pipe ps output into the sort(1)
command if you want to sort the cooked values.


KEY   LONG	   DESCRIPTION
c     cmd	   simple name of executable
C     pcpu	   cpu utilization
f     flags	   flags as in long format F field
g     pgrp	   process group ID
G     tpgid	   controlling tty process group ID
j     cutime	   cumulative user time
J     cstime	   cumulative system time
k     utime	   user time
m     min_flt	   number of minor page faults
M     maj_flt	   number of major page faults
n     cmin_flt	   cumulative minor page faults
N     cmaj_flt	   cumulative major page faults
o     session	   session ID
p     pid	   process ID
P     ppid	   parent process ID

r     rss	   resident set size
R     resident	   resident pages
s     size	   memory size in kilobytes
S     share	   amount of shared pages
t     tty	   the device number of the controlling tty
T     start_time   time process was started
U     uid	   user ID number
u     user	   user name
v     vsize	   total VM size in kB
y     priority	   kernel scheduling priority



AIX FORMAT DESCRIPTORS
This ps supports AIX format descriptors, which work somewhat like the
formatting codes of printf(1) and printf(3). For example, the normal default
output can be produced with this:  ps -eo "%p %y %x %c". The NORMAL codes are
described in the next section.

CODE   NORMAL	HEADER
%C     pcpu	%CPU
%G     group	GROUP
%P     ppid	PPID
%U     user	USER
%a     args	COMMAND
%c     comm	COMMAND
%g     rgroup	RGROUP
%n     nice	NI
%p     pid	PID
%r     pgid	PGID
%t     etime	ELAPSED
%u     ruser	RUSER
%x     time	TIME
%y     tty	TTY
%z     vsz	VSZ


STANDARD FORMAT SPECIFIERS
Here are the different keywords that may be used to control the output format
(e.g. with option -o) or to sort the selected processes with the GNU-style
--sort option.

For example:  ps -eo pid,user,args --sort user

This version of ps tries to recognize most of the keywords used in other
implementations of ps.

The following user-defined format specifiers may contain spaces: args, cmd,
comm, command, fname, ucmd, ucomm, lstart, bsdstart, start.

Some keywords may not be available for sorting.


CODE	   HEADER   DESCRIPTION

%cpu	   %CPU	    cpu utilization of the process in "##.#" format.
		    Currently, it is the CPU time used divided by the time the
		    process has been running (cputime/realtime ratio),
		    expressed as a percentage. It will not add up to 100%
		    unless you are lucky. (alias pcpu).

%mem	   %MEM	    ratio of the process’s resident set size  to the physical
		    memory on the machine, expressed as a percentage.
		    (alias pmem).




args	   COMMAND  command with all its arguments as a string. Modifications
		    to the arguments may be shown. The output in this column
		    may contain spaces. A process marked <defunct> is partly
		    dead, waiting to be fully destroyed by its parent.
		    Sometimes the process args will be unavailable; when this
		    happens, ps will instead print the executable name in
		    brackets. (alias cmd, command). See also the comm format
		    keyword, the -f option, and the c option.
		    When specified last, this column will extend to the edge
		    of the display. If ps can not determine display width, as
		    when output is redirected (piped) into a file or another
		    command, the output width is undefined. (it may be 80,
		    unlimited, determined by the TERM variable, and so on) The
		    COLUMNS environment variable or --cols option may be used
		    to exactly determine the width in this case. The w or -w
		    option may be also be used to adjust width.

blocked	   BLOCKED  mask of the blocked signals, see signal(7). According to
		    the width of the field, a 32-bit or 64-bit mask in
		    hexadecimal format is displayed.
		    (alias sig_block, sigmask).

bsdstart   START    time the command started. If the process was started less
		    than 24 hours ago, the output format is " HH:MM", else it
		    is "mmm dd" (where mmm is the three letters of the month).

bsdtime	   TIME	    accumulated cpu time, user + system. The display format is
		    usually "MMM:SS", but can be shifted to the right if the
		    process used more than 999 minutes of cpu time.

c	   C	    processor utilization. Currently, this is the integer
		    value of the percent usage over the lifetime of the
		    process. (see %cpu).

caught	   CAUGHT   mask of the caught signals, see signal(7). According to
		    the width of the field, a 32 or 64 bits mask in
		    hexadecimal format is displayed.
		    (alias sig_catch, sigcatch).

class	   CLS	    scheduling class of the process. (alias policy, cls).
		    Field’s possible values are:
		    -	not reported
		    TS	SCHED_OTHER
		    FF	SCHED_FIFO
		    RR	SCHED_RR
		    ?	unknown value

cls	   CLS	    scheduling class of the process. (alias policy, class).
		    Field’s possible values are:
		    -	not reported
		    TS	SCHED_OTHER
		    FF	SCHED_FIFO
		    RR	SCHED_RR
		    ?	unknown value

cmd	   CMD	    see args. (alias args, command).












comm	   COMMAND  command name (only the executable name). Modifications to
		    the command name will not be shown. A process marked
		    <defunct> is partly dead, waiting to be fully destroyed by
		    its parent. The output in this column may contain spaces.
		    (alias ucmd, ucomm). See also the args format keyword, the
		    -f option, and the c option.
		    When specified last, this column will extend to the edge
		    of the display. If ps can not determine display width, as
		    when output is redirected (piped) into a file or another
		    command, the output width is undefined. (it may be 80,
		    unlimited, determined by the TERM variable, and so on) The
		    COLUMNS environment variable or --cols option may be used
		    to exactly determine the width in this case. The w or -w
		    option may be also be used to adjust width.

command	   COMMAND  see args. (alias args, cmd).

cp	   CP	    per-mill (tenths of a percent) CPU usage. (see %cpu).

cputime	   TIME	    cumulative CPU time, "[dd-]hh:mm:ss" format. (alias time).

egid	   EGID	    effective group ID number of the process as a decimal
		    integer. (alias gid).

egroup	   EGROUP   effective group ID of the process. This will be the
		    textual group ID, if it can be obtained and the field
		    width permits, or a decimal representation otherwise.
		    (alias group).

eip	   EIP	    instruction pointer.

esp	   ESP	    stack pointer.

etime	   ELAPSED  elapsed time since the process was started, in the
		    form [[dd-]hh:]mm:ss.

euid	   EUID	    effective user ID. (alias uid).

euser	   EUSER    effective user name. This will be the textual user ID,
		    if it can be obtained and the field width permits,
		    or a decimal representation otherwise. The n option can be
		    used to force the decimal representation.
		    (alias uname, user).

f	   F	    flags associated with the process, see the PROCESS FLAGS
		    section. (alias flag, flags).

fgid	   FGID	    filesystem access group ID. (alias fsgid).

fgroup	   FGROUP   filesystem access group ID. This will be the textual
		    user ID, if it can be obtained and the field width
		    permits, or a decimal representation otherwise.
		    (alias fsgroup).

flag	   F	    see f. (alias f, flags).

flags	   F	    see f. (alias f, flag).

fname	   COMMAND  first 8 bytes of the base name of the process’s executable
		    file. The output in this column may contain spaces.

fuid	   FUID	    filesystem access user ID. (alias fsuid).

fuser	   FUSER    filesystem access user ID. This will be the textual
		    user ID, if it can be obtained and the field width
		    permits, or a decimal representation otherwise.


gid	   GID	    see egid. (alias egid).

group	   GROUP    see egroup. (alias egroup).

ignored	   IGNORED  mask of the ignored signals, see signal(7). According to
		    the width of the field, a 32-bit or 64-bit mask in
		    hexadecimal format is displayed. (alias sig_ignore,
		    sigignore).

label	   LABEL    security label, most commonly used for SE Linux context
		    data. This is for the Mandatory Access Control ("MAC")
		    found on high-security systems.

lstart	   STARTED  time the command started.

lwp	   LWP	    lwp (light weight process, or thread) ID of the lwp being
		    reported. (alias spid, tid).

ni	   NI	    nice value. This ranges from 19 (nicest) to -20 (not nice
		    to others), see nice(1). (alias nice).

nice	   NI	    see ni. (alias ni).

nlwp	   NLWP	    number of lwps (threads) in the process. (alias thcount).

nwchan	   WCHAN    address of the kernel function where the process is
		    sleeping (use wchan if you want the kernel function name).
		    Running tasks will display a dash (’-’) in this column.

pcpu	   %CPU	    see %cpu. (alias %cpu).

pending	   PENDING  mask of the pending signals. See signal(7). Signals
		    pending on the process are distinct from signals pending
		    on individual threads. Use the m option or the -m option
		    to see both. According to the width of the field, a 32-bit
		    or 64-bit mask in hexadecimal format is displayed.
		    (alias sig).

pgid	   PGID	    process group ID or, equivalently, the process ID of the
		    process group leader. (alias pgrp).

pgrp	   PGRP	    see pgid. (alias pgid).

pid	   PID	    process ID number of the process.

pmem	   %MEM	    see %mem. (alias %mem).

policy	   POL	    scheduling class of the process. (alias class, cls).
		    Possible values are:
		    -	not reported
		    TS	SCHED_OTHER
		    FF	SCHED_FIFO
		    RR	SCHED_RR
		    ?	unknown value

ppid	   PPID	    parent process ID.

psr	   PSR	    processor that process is currently assigned to.

rgid	   RGID	    real group ID.

rgroup	   RGROUP   real group name. This will be the textual group ID, if it
		    can be obtained and the field width permits, or a decimal
		    representation otherwise.

rss	   RSS	    resident set size, the non-swapped physical memory that a
		    task has used (in kiloBytes). (alias rssize, rsz).


rssize	   RSS	    see rss. (alias rss, rsz).

rsz	   RSZ	    see rss. (alias rss, rssize).

rtprio	   RTPRIO   realtime priority.

ruid	   RUID	    real user ID.

ruser	   RUSER    real user ID. This will be the textual user ID, if it can
		    be obtained and the field width permits, or a decimal
		    representation otherwise.

s	   S	    minimal state display (one character). See section PROCESS
		    STATE CODES for the different values. See also stat if you
		    want additional information displayed. (alias state).

sched	   SCH	    scheduling policy of the process. The policies
		    sched_other, sched_fifo, and sched_rr are respectively
		    displayed as 0, 1, and 2.

sess	   SESS	    session ID or, equivalently, the process ID of the
		    session leader. (alias session, sid).

sgi_p	   P	    processor that the process is currently executing on.
		    Displays "*" if the process is not currently running or
		    runnable.

sgid	   SGID	    saved group ID. (alias svgid).

sgroup	   SGROUP   saved group name. This will be the textual group ID, if it
		    can be obtained and the field width permits, or a decimal
		    representation otherwise.

sid	   SID	    see sess. (alias sess, session).

sig	   PENDING  see pending. (alias pending, sig_pend).

sigcatch   CAUGHT   see caught. (alias caught, sig_catch).

sigignore  IGNORED  see ignored. (alias ignored, sig_ignore).

sigmask	   BLOCKED  see blocked. (alias blocked, sig_block).

size	   SZ	    approximate amount of swap space that would be required if
		    the process were to dirty all writable pages and then be
		    swapped out. This number is very rough!

spid	   SPID	    see lwp. (alias lwp, tid).

stackp	   STACKP   address of the bottom (start) of stack for the process.

start	   STARTED  time the command started. If the process was started less
		    than 24 hours ago, the output format is "HH:MM:SS", else
		    it is "  mmm dd" (where mmm is a three-letter month name).

start_time START    starting time or date of the process. Only the year will
		    be displayed if the process was not started the same year
		    ps was invoked, or "mmmdd" if it was not started the same
		    day, or "HH:MM" otherwise.

stat	   STAT	    multi-character process state. See section PROCESS STATE
		    CODES for the different values meaning. See also s and
		    state if you just want the first character displayed.

state	   S	    see s. (alias s).


suid	   SUID	    saved user ID. (alias svuid).

suser	   SUSER    saved user name. This will be the textual user ID, if it
		    can be obtained and the field width permits, or a decimal
		    representation otherwise. (alias svuser).

svgid	   SVGID    see sgid. (alias sgid).

svuid	   SVUID    see suid. (alias suid).

sz	   SZ	    size in physical pages of the core image of the process.
		    This includes text, data, and stack space. Device mappings
		    are currently excluded; this is subject to change. See vsz
		    and rss.

thcount	   THCNT    see nlwp. (alias nlwp). number of kernel threads owned by
		    the process.

tid	   TID	    see lwp. (alias lwp).

time	   TIME	    cumulative CPU time, "[dd-]hh:mm:ss" format.
		    (alias cputime).

tname	   TTY	    controlling tty (terminal). (alias tt, tty).

tpgid	   TPGID    ID of the foreground process group on the tty (terminal)
		    that the process is connected to, or -1 if the process is
		    not connected to a tty.

tt	   TT	    controlling tty (terminal). (alias tname, tty).

tty	   TT	    controlling tty (terminal). (alias tname, tt).

ucmd	   CMD	    see comm. (alias comm, ucomm).

ucomm	   COMMAND  see comm. (alias comm, ucmd).

uid	   UID	    see euid. (alias euid).

uname	   USER	    see euser. (alias euser, user).

user	   USER	    see euser. (alias euser, uname).

vsize	   VSZ	    see vsz. (alias vsz).

vsz	   VSZ	    virtual memory size of the process in KiB
		    (1024-byte units). Device mappings are currently excluded;
		    this is subject to change. (alias vsize).

wchan	   WCHAN    name of the kernel function in which the process is
		    sleeping, a "-" if the process is running, or a "*" if the
		    process is multi-threaded and ps is not displaying
		    threads.



ENVIRONMENT VARIABLES
The following environment variables could affect ps:

COLUMNS
   Override default display width.

LINES
   Override default display height.

PS_PERSONALITY
   Set to one of posix, old, linux, bsd, sun, digital...
   (see section PERSONALITY below).

CMD_ENV
   Set to one of posix, old, linux, bsd, sun, digital...
   (see section PERSONALITY below).

I_WANT_A_BROKEN_PS
   Force obsolete command line interpretation.

LC_TIME
   Date format.

PS_COLORS
   Not currently supported.

PS_FORMAT
   Default output format override. You may set this to a format string of the
   type used for the -o option. The DefSysV and DefBSD values are particularly
   useful.

PS_SYSMAP
   Default namelist (System.map) location.

PS_SYSTEM_MAP
   Default namelist (System.map) location.

POSIXLY_CORRECT
   Don’t find excuses to ignore bad "features".

POSIX2
   When set to "on", acts as POSIXLY_CORRECT.

UNIX95
   Don’t find excuses to ignore bad "features".

_XPG
   Cancel CMD_ENV=irix non-standard behavior.

In general, it is a bad idea to set these variables. The one exception is
CMD_ENV or PS_PERSONALITY, which could be set to Linux for normal systems.
Without that setting, ps follows the useless and bad parts of the Unix98
standard.



PERSONALITY
390	   like the S/390 OpenEdition ps
aix	   like AIX ps
bsd	   like FreeBSD ps (totally non-standard)
compaq	   like Digital Unix ps
debian	   like the old Debian ps
digital	   like Tru64 (was Digital Unix, was OSF/1) ps
gnu	   like the old Debian ps
hp	   like HP-UX ps
hpux	   like HP-UX ps
irix	   like Irix ps
linux	   ***** RECOMMENDED *****
old	   like the original Linux ps (totally non-standard)
os390	   like OS/390 Open Edition ps
posix	   standard
s390	   like OS/390 Open Edition ps
sco	   like SCO ps
sgi	   like Irix ps
solaris2   like Solaris 2+ (SunOS 5) ps
sunos4	   like SunOS 4 (Solaris 1) ps (totally non-standard)
svr4	   standard
sysv	   standard
tru64	   like Tru64 (was Digital Unix, was OSF/1) ps

unix	   standard
unix95	   standard
unix98	   standard



SEE ALSO
top(1), pgrep(1), pstree(1), proc(5).


STANDARDS
This ps conforms to:

1   Version 2 of the Single Unix Specification
2   The Open Group Technical Standard Base Specifications, Issue 6
3   IEEE Std 1003.1, 2004 Edition
4   X/Open System Interfaces Extension [UP XSI]
5   ISO/IEC 9945:2003


AUTHORS

ps was originally written by Branko Lankester. Michael
K. Johnson re-wrote it significantly to use the proc
filesystem, changing a few things in the process. Michael Shields
added the pid-list feature. Charles Blake
added multi-level sorting, the dirent-style library, the
device name-to-number mmaped database, the approximate binary search directly
on System.map, and many code and documentation cleanups. David Mossberger-Tang
wrote the generic BFD support for psupdate. Albert Cahalan
rewrote ps for full Unix98 and BSD support, along with
some ugly hacks for obsolete and foreign syntax.

Linux				 July 28, 2004				 PS(1)

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