PS(1) | General Commands Manual | PS(1)

# NAME

`ps` — display process status

# SYNOPSIS

`ps` | [[`-`]`AacefHhjkLlmrSTuvwx`] [`-M` core] [`-N` system] [`-O` fmt] [`-o` fmt] [`-p` pid] [`-t` tty] [`-U` user] [`-W` swap]

# DESCRIPTION

The `ps` utility displays information about active processes. When given no options, `ps` prints information about processes of the current user that have a controlling terminal.

The information displayed is selected based on a set of keywords (and for even more control, see the `-L`, `-O`, and `-o` options). The default output format includes, for each process, the process's ID, controlling terminal, state, CPU time (including both user and system time), and associated command.

The options are as follows:

`-A`
  Display information about processes for all users, including those without controlling terminals.
`-a`
  Display information about processes for all users with controlling terminals.
`-c`
  Do not display full command with arguments, but only the executable name. This may be somewhat confusing; for example, all sh(1) scripts will show as “sh”.
`-e`
  Display the environment as well.
`-f`
  Arrange processes into a tree. Each command is ordered and prefixed with indentation text showing sibling and parent/child relationships. If either of the `-m` and `-r` options are also used, they control how sibling processes are sorted relative to each other.
`-H`
  Also display information about kernel visible threads.
`-h`
  Repeat the information header as often as necessary to guarantee one header per page of information.
`-j`
  Print information associated with the following keywords: user, pid, ppid, pgid, sess, jobc, state, tt, time, and command.
`-k`
  Also display information about kernel threads.
`-L`
  List the set of available keywords. This option should not be specified with other options.
`-l`
  Display information associated with the following keywords: uid, pid, ppid, cpu, pri, nice, vsz, rss, wchan, state, tt, time, and command.
`-M` core
  Extract values associated with the name list from the specified core instead of the running kernel.
`-m`
  Sort by memory usage, instead of by start time ID.
`-N` system
  Extract the name list from the specified system instead of the running kernel.
`-O` fmt
  Add the information associated with the space or comma separated list of keywords specified, after the process ID, in the default information display. Keywords may be appended with an equals sign (‘=’) and a string. This causes the printed header to use the specified string instead of the standard header.
`-o` fmt
  Display information associated with the space or comma separated list of keywords specified. Keywords may be appended with an equals sign (‘=’) and a string. This causes the printed header to use the specified string instead of the standard header.
`-p` pid
  Display information associated with the specified process ID.
`-r`
  Sort by current CPU usage, instead of by start time ID.
`-S`
  Change the way the process time is calculated by summing all exited children to their parent process.
`-T`
  Display information about processes attached to the device associated with the standard input.
`-t` tty
  Display information about processes attached to the specified terminal device.
`-U` user
  Only display processes belonging to username or UID user.
`-u`
  Display information associated with the following keywords: user, pid, %cpu, %mem, vsz, rss, tt, state, start, time, and command. The `-u` option implies the `-r` option.
`-v`
  Display information associated with the following keywords: pid, state, time, sl, re, pagein, vsz, rss, lim, tsiz, %cpu, %mem, and command. The `-v` option implies the `-m` option.
`-W` swap
  When not using the running kernel, extract swap information from the specified file.
`-w`
  Use 132 columns to display information, instead of the default, which is the window size. If the `-w` option is specified more than once, `ps` will use as many columns as necessary without regard for window size.
`-x`
  Display information about processes without controlling terminals.

# KEYWORDS

The following is a complete list of the available keywords and their meanings. Several of them have aliases, which are also noted.

`%cpu`
  Alias: `pcpu`. The CPU utilization of the process; this is a decaying average over up to a minute of previous (real) time. Since the time base over which this is computed varies (since processes may be very young), it is possible for the sum of all `%cpu` fields to exceed 100%.
`%mem`
  Alias: `pmem`. The percentage of real memory used by this process.
`acflag`
  Alias: `acflg`. Accounting flag.
`command`
  Alias: `args`. Command and arguments.
`cpu`
  Short-term CPU usage factor (for scheduling).
`cpuid`
  CPU ID (zero on single processor systems).
`cwd`
  Current working directory.
`dsiz`
  Data size, in Kilobytes.
`etime`
  Elapsed time since the process was started.
`flags`
  Alias: `f`. The thread flags (in hexadecimal), as defined in the include file `<sys/proc.h>`:

      P_INKTR           0x1 writing ktrace(2) record
      P_PROFPEND        0x2 this thread needs SIGPROF
      P_ALRMPEND        0x4 this thread needs SIGVTALRM
      P_SIGSUSPEND      0x8 need to restore before-suspend mask
      P_CANTSLEEP      0x10 this thread is not permitted to sleep
      P_SINTR          0x80 sleep is interruptible
      P_SYSTEM        0x200 system process: no sigs, stats, or
                            swapping
      P_TIMEOUT       0x400 timing out during sleep
      P_WEXIT        0x2000 working on exiting
      P_OWEUPC       0x8000 profiling sample needs recording
      P_SUSPSINGLE  0x80000 need to suspend for single threading
      P_THREAD    0x4000000 not the original thread
      P_SUSPSIG   0x8000000 stopped because of a signal
      P_CPUPEG   0x40000000 do not move to another cpu

`gid`
  Effective group.
`group`
  Text name of effective group ID.
`inblk`
  Alias: `inblock`. Total blocks read.
`jobc`
  Job control count.
`ktrace`
  Tracing flags.
`ktracep`
  Tracing vnode.
`lim`
  The soft limit on memory used, specified via a call to setrlimit(2).
`logname`
  Alias: `login`. Login name of user who started the process.
`lstart`
  The exact time the command started, using the “%c” format described in strftime(3).
`majflt`
  Total page faults.
`maxrss`
  Maximum resident set size (in 1024 byte units).
`minflt`
  Total page reclaims.
`msgrcv`
  Total messages received (reads from pipes/sockets).
`msgsnd`
  Total messages sent (writes on pipes/sockets).
`nice`
  Alias: `ni`. The process scheduling increment (see setpriority(2)).
`nivcsw`
  Total involuntary context switches.
`nsigs`
  Alias: `nsignals`. Total signals taken.
`nswap`
  Total swaps in/out.
`nvcsw`
  Total voluntary context switches.
`nwchan`
  Wait channel (as an address).
`oublk`
  Alias: `oublock`. Total blocks written.
`p_ru`
  Resource usage (valid only for zombie processes).
`paddr`
  Swap address.
`pagein`
  Pageins (same as `majflt`).
`pgid`
  Process group number.
`pid`
  Process ID.
`pledge`
  Comma separated list of active pledge(2) promises.
`ppid`
  Parent process ID.
`pri`
  Scheduling priority.
`procflags`
  The process flags (in hexadecimal), as defined in the include file `<sys/proc.h>`:

      PS_CONTROLT            0x1 process has a controlling
                                 terminal
      PS_EXEC                0x2 process called exec(3)
      PS_INEXEC              0x4 process is doing an exec right
                                 now
      PS_EXITING             0x8 process is exiting
      PS_SUGID              0x10 process had set ID privileges
                                 since last exec
      PS_SUGIDEXEC          0x20 last exec(3) was set[ug]id
      PS_PPWAIT             0x40 parent is waiting for process
                                 to exec/exit
      PS_ISPWAIT            0x80 process is parent of PPWAIT
                                 child
      PS_PROFIL            0x100 process has started profiling
      PS_TRACED            0x200 process is being traced
      PS_WAITED            0x400 debugging process has waited
                                 for child
      PS_COREDUMP          0x800 busy coredumping
      PS_SINGLEEXIT       0x1000 other threads must die
      PS_SINGLEUNWIND     0x2000 other threads must unwind
      PS_NOZOMBIE         0x4000 pid 1 waits for me instead of
                                 dad
      PS_STOPPING         0x8000 just stopped, need to send
                                 SIGCHLD
      PS_SYSTEM          0x10000 No signals, stats or swapping
      PS_EMBRYO          0x20000 New process, not yet fledged
      PS_ZOMBIE          0x40000 Dead and ready to be waited for
      PS_NOBROADCASTKILL 0x80000 Process excluded from kill -1
      PS_PLEDGE         0x100000 process has called pledge(2)
      PS_EXECPLEDGE	0x00400000 has exec pledges
      PS_ORPHAN	0x00800000 process is on an orphan list
      PS_CHROOT	0x01000000 process is chrooted
      PS_CONTINUED    0x20000000 process continued from stopped state
                                 but has not been waited for yet
      PS_STOPPED      0x40000000 process is in stopped state

`re`
  Core residency time (in seconds; 127 = infinity).
`rgid`
  Real group ID.
`rgroup`
  Text name of real group ID.
`rlink`
  Reverse link on run queue, or 0.
`rss`
  The real memory (resident set) size of the process (in 1024 byte units).
`rtable`
  Routing table.
`ruid`
  Real user ID.
`ruser`
  User name (from `ruid`).
`sess`
  Session ID (PID of session leader).
`sig`
  Alias: `pending`. Pending signals.
`sigcatch`
  Alias: `caught`. Caught signals.
`sigignore`
  Alias: `ignored`. Ignored signals.
`sigmask`
  Alias: `blocked`. Blocked signals.
`sl`
  Sleep time (in seconds; 127 = infinity).
`ssiz`
  Stack size, in Kilobytes.
`start`
  The time the command started. If the command started less than 24 hours ago, the start time is displayed using the “%l:%M%p” format described in strftime(3). If the command started less than 7 days ago, the start time is displayed using the “%a%I%p” format. Otherwise, the start time is displayed using the “%e%b%y” format.
`state`
  Alias: `stat`. The state is given by a sequence of letters, for example, “RWN”. The first letter indicates the run state of the process:

  D
    Marks a process in disk (or other short term, uninterruptible) wait.
  I
    Marks a process that is idle (sleeping for longer than about 20 seconds).
  R
    Marks a runnable process.
  S
    Marks a process that is sleeping for less than about 20 seconds.
  T
    Marks a stopped process.
  Z
    Marks a dead process (a “zombie”).

  Additional characters after these, if any, indicate additional state information:

  +
    The process is in the foreground process group of its controlling terminal.
  <
    The process has a raised CPU scheduling priority (see setpriority(2)).
  >
    The process has specified a soft limit on memory requirements and is currently exceeding that limit; such a process is (necessarily) not swapped.
  c
    The process is chrooted.
  E
    The process is trying to exit.
  K
    The process is a kernel thread.
  N
    The process has a reduced CPU scheduling priority.
  p
    The process has called pledge(2).
  s
    The process is a session leader.
  U
    The process has unveiled, and unveil(2) is now locked.
  u
    The process has unveiled, but not yet locked unveil(2) (could be a program error).
  V
    The process is suspended during a vfork(2).
  X
    The process is being traced or debugged.
  /n
    On multiprocessor machines, specifies processor number n.
`supgid`
  Group IDs of supplementary groups.
`supgrp`
  Group names of supplementary groups.
`svgid`
  Saved GID from a setgid executable.
`svuid`
  Saved UID from a setuid executable.
`tdev`
  Controlling terminal device number.
`tid`
  Thread ID. Used together with `-H`.
`time`
  Alias: `cputime`. Accumulated CPU time, user + system.
`tpgid`
  Controlling terminal process group ID.
`tsess`
  Controlling terminal session pointer.
`tsiz`
  Text size, in Kilobytes.
`tt`
  An abbreviation for the pathname of the controlling terminal, if any. The abbreviation consists of the two letters following “/dev/tty”, or, for the console, “co”. This is followed by a ‘-’ if the process can no longer reach that controlling terminal (i.e. it has been revoked).
`tty`
  Full name of controlling terminal.
`ucomm`
  Alias: `comm`. Name to be used for accounting.
`uid`
  Effective user ID.
`upr`
  Alias: `usrpri`. Scheduling priority on return from system call.
`user`
  User name (from `uid`).
`vsz`
  Alias: `vsize`. Virtual size, in Kilobytes.
`wchan`
  The event (an address in the system) on which a process waits. When printed numerically, the initial part of the address is trimmed off and the result is printed in hex; for example, 0x80324000 prints as 324000.
`xstat`
  Exit or stop status (valid only for stopped or zombie process).

# ENVIRONMENT

The following environment variables affect the execution of `ps`:

`COLUMNS`
  If set to a positive integer, output is formatted to the given width in columns. Otherwise, `ps` defaults to the terminal width minus 1. If none of `stdout`, `stderr`, and `stdin` are a terminal, 79 columns are used.
`LC_CTYPE`
  The character encoding locale(1). It decides which byte sequences form characters, which characters are printable, and what their display width is. If unset or set to "C", "POSIX", or an unsupported value, only printable ASCII characters are printed. Tabs, newlines, non-printable ASCII characters, and non-ASCII bytes are encoded with vis(3). If UTF-8 output is enabled, valid characters that are not printable are replaced with the Unicode replacement character U+FFFD. These rules for example apply to command names, arguments, and environments and to directory, user, and group names.
`TZ`
  The time zone to use when displaying dates. See environ(7) for more information.

# FILES

/dev
  special files and device names
/var/db/kvm_bsd.db
  system namelist database
/var/run/dev.db
  /dev name database

# EXIT STATUS

The `ps` utility exits 0 on success, and >0 if an error occurs.

# EXAMPLES

Display information on all system processes:

`$ ps -auxw`

# SEE ALSO

fstat(1), kill(1), netstat(1), pgrep(1), pkill(1), procmap(1), systat(1), top(1), w(1), kvm(3), strftime(3), dev_mkdb(8), iostat(8), pstat(8), vmstat(8)

# STANDARDS

The `ps` utility is compliant with the IEEE Std 1003.1-2008 (“POSIX.1”) specification, except that the flag [`-G`] is unsupported and the flags [`-ptU`] support only single arguments, not lists.

The flags [`-defglnu`] are marked by IEEE Std 1003.1-2008 (“POSIX.1”) as being an X/Open System Interfaces option. Of these, [`-dfgn`] are not supported by this implementation of `ps`; behaviour for the flags [`-elu`] differs between this implementation and the X/Open System Interfaces option of IEEE Std 1003.1-2008 (“POSIX.1”).

The flags [`-cfHhjkLMmNOrSTvWwx`] are extensions to IEEE Std 1003.1-2008 (“POSIX.1”).

Only the following keywords are recognised by IEEE Std 1003.1-2008 (“POSIX.1”): `args`, `comm`, `etime`, `group`, `nice`, `pcpu`, `pgid`, `pid`, `ppid`, `rgroup`, `ruser`, `time`, `tty`, `user`, and `vsz`.

# HISTORY

A `ps` command first appeared in Version 3 AT&T UNIX.

# CAVEATS

When printing using the `command` keyword, a process that has exited and has a parent that has not yet waited for the process (in other words, a zombie) is listed as “⟨defunct⟩”, and a process which is blocked while trying to exit is listed as “⟨exiting⟩”. `ps` makes an educated guess as to the file name and arguments given when the process was created by examining memory or the swap area. The method is inherently somewhat unreliable and in any event a process is entitled to destroy this information, so the names cannot be depended on too much. The `ucomm` (accounting) keyword can, however, be depended on.

The information displayed is only a snapshot of a constantly changing system.

August 15, 2025 | Debian