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 [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 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.

       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 IO)
               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 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 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 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
                                                     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                              CGROUPNSUnique 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).

       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 T{
       environment variables for the process.
       T}
       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).

       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).

       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 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, 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:

       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@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 2023-12-22.  (At
       that time, the date of the most recent commit that was found in
       the repository was 2023-10-16.)  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                      2023-10-04                          PS(1)

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