ps(1) - Linux manual page

ps(1) — Linux manual page

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 | BUGS | SEE ALSO | STANDARDS | AUTHOR | COLOPHON

PS(1)                         User Commands                        PS(1)

NAME         top

       ps - report a snapshot of the current processes.

SYNOPSIS         top

       ps [option ...]

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 instead.

       This version of ps accepts several kinds of options.

       •   Unix options, which may be grouped and must be preceded by a
           dash.

       •   BSD options, which may be grouped and must not be used with a
           dash.

       •   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.

       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 -Ao pid,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 -q 42 -o comm=

SIMPLE PROCESS SELECTION         top

       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.

       -A     Select all processes.  Identical to -e.

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

       -d     Select all processes except session leaders.

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

       -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.

       -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.

       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.

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

       123    Identical to --pid 123.

       +123   Identical to --sid 123.

       -123   Select by process group ID (PGID).

       -C cmdlist
              Select by command name.  This selects the processes whose
              executable name is given in cmdlist.  NOTE: The command
              name is not the same as the command line. Previous
              versions of procps and the kernel truncated this command
              name to 15 characters. This limitation is no longer
              present in both. If you depended on matching only 15
              characters, you may no longer get a match.

       -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).

       -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.

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

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

       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.

       --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.

       q pidlist
              Select by process ID (quick mode).  Identical to -q and
              --quick-pid.

       -q pidlist
              Select by PID (quick mode).  This selects the processes
              whose process ID numbers appear in pidlist.  With this
              option ps reads the necessary info only for the pids
              listed in the pidlist and doesn't apply additional
              filtering rules. The order of pids is unsorted and
              preserved. No additional selection options, sorting and
              forest type listings are allowed in this mode.  Identical
              to q and --quick-pid.

       --quick-pid pidlist
              Select by process ID (quick mode).  Identical to -q and q.

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

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

       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.

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

       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).

       -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.

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

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

OUTPUT FORMAT CONTROL         top

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

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

       --context
              Display security context format (for SELinux).

       -f     Do 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.

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

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

       j      BSD job control format.

       -j     Jobs format.

       l      Display BSD long format.

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

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

       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.

       -O format
              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
              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.

       -P     Add a column showing psr.

       s      Display signal format.

       u      Display user-oriented format.

       v      Display virtual memory format.

       X      Register format.

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

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

OUTPUT MODIFIERS         top

       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 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.

       --cols n
              Set screen width.

       --columns n
              Set screen width.

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

       -D format
              Set the date format of the lstart field to format. This
              format is parsed by strftime(3) and should be a maximum of
              24 characters to not mis-align columns.

       --date-format format
              Identical to -D.

       e      Show the environment after the command.

       f      ASCII art process hierarchy (forest).

       --forest
              ASCII art process tree.

       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.

       -H     Show process hierarchy (forest).

       --headers
              Repeat header lines, one per page of output.

       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

       --lines n
              Set screen height.

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

       --no-headers
              Print no header line at all.  --no-heading is an alias for
              this option.

       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.

       --rows n
              Set screen height.

       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.

       --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

       --signames
              Show signal masks using abbreviated signal names and
              expands the collumn.  If the column width cannot show all
              signals, the column will end with a plus "+".  Columns
              with only a hyphen have no signals.

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

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

       --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.

       m      Show threads after processes.

       -m     Show threads after processes.

       -T     Show threads, possibly with SPID column.

OTHER INFORMATION         top

       --help section
              Print a help message.  The section argument can be one of
              simple, list, output, threads, misc, or all.  The argument
              can be shortened to one of the underlined letters as in:
              s|l|o|t|m|a.

       --info Print debugging info.

       L      List all format specifiers.

       V      Print the procps-ng version.

       -V     Print the procps-ng version.

       --version
              Print the procps-ng 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.

       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.

       If the length of the username is greater than the width of the
       display column, the username will be truncated.  See the -o and
       -O formatting options to customize length.

       Commands options such as ps -aux are not recommended as it is a
       confusion of two different standards.  According to the POSIX and
       Unix standards, the above command asks to display all processes
       with a TTY (generally the commands users are running) plus all
       processes owned by a user named x.  If that user doesn't exist,
       then ps will assume you really meant "ps aux".

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 I/O)
               I    idle kernel thread
               R    running or runnable (on run queue)
               S    interruptible sleep (waiting for an
                    event to complete)
               T    stopped by job control signal
               t    stopped by debugger during the tracing
               W    paging (not valid since Linux 2.6)
               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 I/O)
               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 kibibytes
       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 KiB
       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).  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).

       ag_id        AGID       The autogroup identifier associated with
                               a process which operates in conjunction
                               with the CFS scheduler to improve
                               interactive desktop performance.

       ag_nice      AGNI       The autogroup nice value which affects
                               scheduling of all processes in that
                               group.

       args         COMMAND    A 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 arguments will be
                               unavailable; when this happens, ps
                               instead reports 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 the 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 or 64-bit mask in hexadecimal
                               format is displayed, unless the
                               --signames option is used.  (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:SS" (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, unless
                               the --signames option is used.  (alias
                               sig_catch, sigcatch).

       cgname       CGNAME     display name of control groups to which
                               the process belongs.

       cgroup       CGROUP     display control groups to which the
                               process belongs.

       cgroupns     CGROUPNS   Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       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
                                        DLN  SCHED_DEADLINE
                                        ?    unknown value

       cls          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
                                        DLN  SCHED_DEADLINE
                                        ?    unknown value

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

       comm         COMMAND    command name (only the executable name).
                               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, command).

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

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

       cputimes     TIME       cumulative CPU time in seconds (alias
                               times).

       cuc          %CUC       The CPU utilization of a process,
                               including dead children, in an extended
                               "##.###" format.  (see also %cpu, c, cp,
                               cuu, pcpu).

       cuu          %CUU       The CPU utilization of a process in an
                               extended "##.###" format.  (see also
                               %cpu, c, cp, cuc, pcpu).

       docker       DOCKER     The abbreviated id of the docker
                               container within which a task is running.
                               If a process is not running inside a
                               container, a dash ('-') will be shown.

       drs          DRS        data resident set size, the amount of
                               private memory reserved by a process.  It
                               is also known as DATA. Such memory may
                               not yet be mapped to rss but will always
                               be included included in the vsz amount.

       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. As of kernel 4.9.xx
                               will be zeroed out unless task is exiting
                               or being core dumped.

       esp          ESP        stack pointer. As of kernel 4.9.xx will
                               be zeroed out unless task is exiting or
                               being core dumped.

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

       etimes       ELAPSED    elapsed time since the process was
                               started, in seconds.

       environ      ENVIRON    environment variables for the process.
       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).

       exe          EXE        path to the executable. Useful if path
                               cannot be printed via cmd, comm or args
                               format options.

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

       fds          FDS        total open file descriptors.

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

       fgroup       FGROUP     filesystem access group ID.  This will be
                               the textual group 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).

       htprv        HTPRV      The amount of private memory backed by
                               hugetlbfs page which is not counted in
                               the rss or pss format options.

       htshr        HTSHR      The amount of shared memory backed by
                               hugetlbfs page which is not counted in
                               the rss or pss format options.

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

       ipcns        IPCNS      Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

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

       lstart       STARTED    time the command started. This will be in
                               the form "DDD mmm HH:MM:SS YYY" unless
                               changed by the -D option.

       lsession     SESSION    displays the login session identifier of
                               a process, if systemd support has been
                               included.

       luid         LUID       displays Login ID associated with a
                               process.

       lwp          LWP        light weight process (thread) ID of the
                               dispatchable entity (alias spid, tid).
                               See tid for additional information.

       lxc          LXC        The name of the lxc container within
                               which a task is running.  If a process is
                               not running inside a container, a dash
                               ('-') will be shown.

       machine      MACHINE    displays the machine name for processes
                               assigned to VM or container, if systemd
                               support has been included.

       maj_flt      MAJFLT     The number of major page faults that have
                               occurred with this process.

       min_flt      MINFLT     The number of minor page faults that have
                               occurred with this process.

       mntns        MNTNS      Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       netns        NETNS      Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       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).

       numa         NUMA       The node associated with the most
                               recently used processor.  A -1 means that
                               NUMA information is unavailable.

       nwchan       WCHAN      address of the kernel function where the
                               process is sleeping (use wchan if you
                               want the kernel function name).

       oom          OOM        Out of Memory Score. The value, ranging
                               from 0 to +1000, used to select task(s)
                               to kill when memory is exhausted.

       oomadj       OOMADJ     Out of Memory Adjustment Factor. The
                               value is added to the current out of
                               memory score which is then used to
                               determine which task to kill when memory
                               is exhausted.

       ouid         OWNER      displays the Unix user identifier of the
                               owner of the session of a process, if
                               systemd support has been included.

       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 or 64
                               bits mask in hexadecimal format is
                               displayed, unless the --signames option
                               is used.  (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        a number representing the process ID
                               (alias tgid).

       pidns        PIDNS      Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       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
                                        DLN  SCHED_DEADLINE
                                        ?    unknown value

       ppid         PPID       parent process ID.

       pri          PRI        priority of the process.  Higher number
                               means higher priority.

       psr          PSR        processor that process last executed on.

       pss          PSS        Proportional share size, the non-swapped
                               physical memory, with shared memory
                               proportionally accounted to all tasks
                               mapping it.

       rbytes       RBYTES     Number of bytes which this process really
                               did cause to be fetched from the storage
                               layer.

       rchars       RCHARS     Number of bytes which this task has
                               caused to be read from storage.

       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.

       rops         ROPS       Number of read I/O operations—that is,
                               system calls such as read(2) and
                               pread(2).

       rss          RSS        resident set size, the non-swapped
                               physical memory that a task has used (in
                               kibibytes).  (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, SCHED_IDLE and SCHED_DEADLINE
                               are respectively displayed as 0, 1, 2, 3,
                               4, 5 and 6.

       seat         SEAT       displays the identifier associated with
                               all hardware devices assigned to a
                               specific workplace, if systemd support
                               has been included.

       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         SIZE       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!

       slice        SLICE      displays the slice unit which a process
                               belongs to, if systemd support has been
                               included.

       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 bsdstart, start,
                               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).

       stime        STIME      see start_time. (alias start_time).

       suid         SUID       saved user ID.  (alias svuid).

       supgid       SUPGID     group ids of supplementary groups, if
                               any.  See getgroups(2).

       supgrp       SUPGRP     group names of supplementary groups, if
                               any.  See getgroups(2).

       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.

       tgid         TGID       a number representing the thread group to
                               which a task belongs (alias pid).  It is
                               the process ID of the thread group
                               leader.

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

       tid          TID        the unique number representing a
                               dispatchable entity (alias spid, tid).
                               This value may also appear as: a process
                               ID (pid); a process group ID (pgrp); a
                               session ID for the session leader (sid);
                               a thread group ID for the thread group
                               leader (tgid); and a tty process group ID
                               for the process group leader (tpgid).

       time         TIME       cumulative CPU time, "[DD-]HH:MM:SS"
                               format.  (alias cputime).

       timens       TIMENS     Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       times        TIME       cumulative CPU time in seconds (alias
                               cputimes).

       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.

       trs          TRS        text resident set size, the amount of
                               physical memory devoted to executable
                               code.

       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).

       unit         UNIT       displays unit which a process belongs to,
                               if systemd support has been included.

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

       userns       USERNS     Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       uss          USS        Unique set size, the non-swapped physical
                               memory, which is not shared with an
                               another task.

       utsns        UTSNS      Unique inode number describing the
                               namespace the process belongs to.  See
                               namespaces(7).

       uunit        UUNIT      displays user unit which a process
                               belongs to, if systemd support has been
                               included.

       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).

       wbytes       WBYTES     Number of bytes which this process caused
                               to be sent to the storage layer.

       wcbytes      WCBYTES    Number of cancelled write bytes.

       wchan        WCHAN      name of the kernel function in which the
                               process is sleeping.

       wchars       WCHARS     Number of bytes which this task has
                               caused, or shall cause to be written to
                               disk.

       wops         WOPS       Number of write I/O operations—that is,
                               system calls such as write(2) and
                               pwrite(2).

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.

       LIBPROC_HIDE_KERNEL
          Set this to any value to hide kernel threads normally
          displayed with the -e option. This is equivalent to selecting
          --ppid 2 -p 2 --deselect instead. Also works in BSD mode.

       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.

       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 OS/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

BUGS         top

       The fields bsdstart and start will only show the abbreviated
       month name in English. The fields lstart and stime will show the
       abbreviated month name in the configured locale but may exceed
       the column width due to the different lengths for abbreviated
       month and day names across languages.

SEE ALSO         top

       pgrep(1), pstree(1), top(1), strftime(3), proc(5).

STANDARDS         top

       This ps conforms to the following standards.

       •   Version 2 of the Single Unix Specification

       •   The Open Group Technical Standard Base Specifications,
           Issue 6

       •   IEEE Std 1003.1, 2004 Edition

       •   X/Open System Interfaces Extension [UP XSI]

       •   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@freelists.org⟩.  No
       subscription is required or suggested.

COLOPHON         top

       This page is part of the procps-ng (/proc filesystem utilities)
       project.  Information about the project can be found at 
       ⟨https://gitlab.com/procps-ng/procps⟩.  If you have a bug report
       for this manual page, see
       ⟨https://gitlab.com/procps-ng/procps/blob/master/Documentation/bugs.md⟩.
       This page was obtained from the project's upstream Git repository
       ⟨https://gitlab.com/procps-ng/procps.git⟩ on 2024-06-14.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2024-06-04.)  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
       corrections 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

procps-ng                      2024-01-30                          PS(1)

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