NAME | SYNOPSIS | DESCRIPTION | EXAMPLES | SIMPLE PROCESS SELECTION | PROCESS SELECTION BY LIST | OUTPUT FORMAT CONTROL | OUTPUT MODIFIERS | THREAD DISPLAY | OTHER INFORMATION | NOTES | PROCESS FLAGS | PROCESS STATE CODES | OBSOLETE SORT KEYS | AIX FORMAT DESCRIPTORS | STANDARD FORMAT SPECIFIERS | ENVIRONMENT VARIABLES | PERSONALITY | SEE ALSO | STANDARDS | AUTHOR | COLOPHON

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

NAME         top

ps - report a snapshot of the current processes.

SYNOPSIS         top

ps [options]

DESCRIPTION         top

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         top

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         top

-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 both 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         top

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         top

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.

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

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

OUTPUT MODIFIERS         top

-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         top

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         top

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         top

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         top

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         top

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         top

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         top

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         top

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). See also lstart, start, start_time, and
                    stime.

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
                    B   SCHED_BATCH
                    ISO SCHED_ISO
                    IDL SCHED_IDLE
                    ?   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
                    B   SCHED_BATCH
                    ISO SCHED_ISO
                    IDL SCHED_IDLE
                    ?   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. See also bsdstart, start,
                    start_time, and stime.

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
                    B   SCHED_BATCH
                    ISO SCHED_ISO
                    IDL SCHED_IDLE
                    ?   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_NORMAL), SCHED_FIFO, SCHED_RR,
                    SCHED_BATCH, SCHED_ISO, and SCHED_IDLE are respectively
                    displayed as 0, 1, 2, 3, 4, and 5.

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). See also lstart, bsdstart, start_time, and
                    stime.

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. See also bsdstart,
                    start, lstart, and stime.

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         top

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         top

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

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

STANDARDS         top

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

AUTHOR         top

ps was originally written by Branko Lankester <lankeste@fwi.uva.nl>. Michael
K. Johnson <johnsonm@redhat.com> re-wrote it significantly to use the proc
filesystem, changing a few things in the process. Michael Shields
<mjshield@nyx.cs.du.edu> added the pid-list feature. Charles Blake
<cblake@bbn.com> 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
<albert@users.sf.net> rewrote ps for full Unix98 and BSD support, along with
some ugly hacks for obsolete and foreign syntax.

Please send bug reports to <procps-feedback@lists.sf.net>. No subscription
is required or suggested.

COLOPHON         top

This page is part of the procps (/proc filesystem utilities) project.
Information about the project can be found at 
⟨http://procps.sourceforge.net/⟩. If you have a bug report for this manual
page, see ⟨http://procps.sourceforge.net/faq.html⟩. This page was obtained
from the tarball procps-3.2.8.tar.gz fetched from 
⟨http://procps.sourceforge.net/download.html⟩ on 2014-09-06. If you discover
any rendering problems in this HTML version of the page, or you believe
there is a better or more up-to-date source for the page, or you have cor‐
rections or improvements to the information in this COLOPHON (which is not
part of the original manual page), send a mail to man-pages@man7.org

Linux                           July 28, 2004                          PS(1)