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PS(1) User Commands PS(1)
NAME
ps - report a snapshot of the current processes.
SYNOPSIS
ps [options]
DESCRIPTION
ps displays information about a selection of the active processes.
If you want a repetitive update of the selection and the displayed
information, use top(1) instead.
This version of ps accepts several kinds of options:
1 UNIX options, which may be grouped and must be preceded by a
dash.
2 BSD options, which may be grouped and must not be used with a
dash.
3 GNU long options, which are preceded by two dashes.
Options of different types may be freely mixed, but conflicts can
appear. There are some synonymous options, which are functionally
identical, due to the many standards and ps implementations that
this ps is compatible with.
Note that "ps -aux" is distinct from "ps aux". The POSIX and UNIX
standards require that "ps -aux" print all processes owned by a
user named "x", as well as printing all processes that would be
selected by the -a option. If the user named "x" does not exist,
this ps may interpret the command as "ps aux" instead and print a
warning. This behavior is intended to aid in transitioning old
scripts and habits. It is fragile, subject to change, and thus
should not be relied upon.
By default, ps selects all processes with the same effective user
ID (euid=EUID) as the current user and associated with the same
terminal as the invoker. It displays the process ID (pid=PID),
the terminal associated with the process (tname=TTY), the
cumulated CPU time in [DD-]hh:mm:ss format (time=TIME), and the
executable name (ucmd=CMD). Output is unsorted by default.
The use of BSD-style options will add process state (stat=STAT) to
the default display and show the command args (args=COMMAND)
instead of the executable name. You can override this with the
PS_FORMAT environment variable. The use of BSD-style options will
also change the process selection to include processes on other
terminals (TTYs) that are owned by you; alternately, this may be
described as setting the selection to be the set of all processes
filtered to exclude processes owned by other users or not on a
terminal. These effects are not considered when options are
described as being "identical" below, so -M will be considered
identical to Z and so on.
Except as described below, process selection options are additive.
The default selection is discarded, and then the selected
processes are added to the set of processes to be displayed. A
process will thus be shown if it meets any of the given selection
criteria.
EXAMPLES
To see every process on the system using standard syntax:
ps -e
ps -ef
ps -eF
ps -ely
To see every process on the system using BSD syntax:
ps ax
ps axu
To print a process tree:
ps -ejH
ps axjf
To get info about threads:
ps -eLf
ps axms
To get security info:
ps -eo euser,ruser,suser,fuser,f,comm,label
ps axZ
ps -eM
To see every process running as root (real & effective ID) in user
format:
ps -U root -u root u
To see every process with a user-defined format:
ps -eo pid,tid,class,rtprio,ni,pri,psr,pcpu,stat,wchan:14,comm
ps axo stat,euid,ruid,tty,tpgid,sess,pgrp,ppid,pid,pcpu,comm
ps -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
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
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 --pid 123.
-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
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.
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
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).
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
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
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
--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
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 length 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
The sum of these values is displayed in the "F" column, which is
provided by the flags output specifier:
1 forked but didn't exec
4 used super-user privileges
PROCESS STATE CODES
Here are the different values that the s, stat and state output
specifiers (header "STAT" or "S") will display to describe the
state of a process:
D uninterruptible sleep (usually IO)
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
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
This ps supports AIX format descriptors, which work somewhat like
the formatting codes of printf(1) and printf(3). For example, the
normal default output can be produced with this: ps -eo "%p %y %x
%c". The NORMAL codes are described in the next section.
CODE NORMAL HEADER
%C pcpu %CPU
%G group GROUP
%P ppid PPID
%U user USER
%a args COMMAND
%c comm COMMAND
%g rgroup RGROUP
%n nice NI
%p pid PID
%r pgid PGID
%t etime ELAPSED
%u ruser RUSER
%x time TIME
%y tty TTY
%z vsz VSZ
STANDARD FORMAT SPECIFIERS
Here are the different keywords that may be used to control the
output format (e.g., with option -o) or to sort the selected
processes with the GNU-style --sort option.
For example: ps -eo pid,user,args --sort user
This version of ps tries to recognize most of the keywords used in
other implementations of ps.
The following user-defined format specifiers may contain spaces:
args, cmd, comm, command, fname, ucmd, ucomm, lstart, bsdstart,
start.
Some keywords may not be available for sorting.
CODE HEADER DESCRIPTION
%cpu %CPU cpu utilization of the process in "##.#"
format. Currently, it is the CPU time used
divided by the time the process has been
running (cputime/realtime ratio), expressed
as a percentage. It will not add up to 100%
unless you are lucky. (alias pcpu).
%mem %MEM ratio of the process's resident set size to
the physical memory on the machine,
expressed as a percentage. (alias pmem).
args COMMAND command with all its arguments as a string.
Modifications to the arguments may be shown.
The output in this column may contain
spaces. A process marked <defunct> is
partly dead, waiting to be fully destroyed
by its parent. Sometimes the process args
will be unavailable; when this happens, ps
will instead print the executable name in
brackets. (alias cmd, command). See also
the comm format keyword, the -f option, and
the c option.
When specified last, this column will extend
to the edge of the display. If ps can not
determine display width, as when output is
redirected (piped) into a file or another
command, the output width is undefined (it
may be 80, unlimited, determined by the TERM
variable, and so on). The COLUMNS
environment variable or --cols option may be
used to exactly determine the width in this
case. The w or -w option may be also be
used to adjust width.
blocked BLOCKED mask of the blocked signals, see signal(7).
According to the width of the field, a 32 or
64-bit mask in hexadecimal format is
displayed. (alias sig_block, sigmask).
bsdstart START time the command started. If the process
was started less than 24 hours ago, the
output format is " HH:MM", else it is "
Mmm: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. (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.
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).
Modifications to the command name will not
be shown. A process marked <defunct> is
partly dead, waiting to be fully destroyed
by its parent. The output in this column
may contain spaces. (alias ucmd, ucomm).
See also the args format keyword, the -f
option, and the c option.
When specified last, this column will extend
to the edge of the display. If ps can not
determine display width, as when output is
redirected (piped) into a file or another
command, the output width is undefined (it
may be 80, unlimited, determined by the TERM
variable, and so on). The COLUMNS
environment variable or --cols option may be
used to exactly determine the width in this
case. The w or -w option may be also be
used to adjust width.
command COMMAND See args. (alias args, 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).
drs DRS data resident set size, the amount of
physical memory devoted to other than
executable code.
egid EGID effective group ID number of the process as
a decimal integer. (alias gid).
egroup EGROUP effective group ID of the process. This
will be the textual group ID, if it can be
obtained and the field width permits, or a
decimal representation otherwise. (alias
group).
eip EIP instruction pointer.
esp ESP stack pointer.
etime ELAPSED elapsed time since the process was started,
in the form [[DD-]hh:]mm:ss.
etimes ELAPSED elapsed time since the process was started,
in seconds.
euid EUID effective user ID (alias uid).
euser EUSER effective user name. This will be the
textual user ID, if it can be obtained and
the field width permits, or a decimal
representation otherwise. The n option can
be used to force the decimal representation.
(alias uname, user).
f F flags associated with the process, see the
PROCESS FLAGS section. (alias flag, flags).
fgid FGID filesystem access group ID. (alias fsgid).
fgroup FGROUP filesystem access group ID. This will be
the textual 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. (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. See also
bsdstart, start, start_time, and stime.
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 assocated 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). Running tasks
will display a dash ('-') in this column.
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. (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 lower priority.
psr PSR processor that process is currently assigned
to.
rgid RGID real group ID.
rgroup RGROUP real group name. This will be the textual
group ID, if it can be obtained and the
field width permits, or a decimal
representation otherwise.
rss RSS resident set size, the non-swapped physical
memory that a task has used (in kilobytes).
(alias rssize, rsz).
rssize RSS see rss. (alias rss, rsz).
rsz RSZ see rss. (alias rss, rssize).
rtprio RTPRIO realtime priority.
ruid RUID real user ID.
ruser RUSER real user ID. This will be the textual user
ID, if it can be obtained and the field
width permits, or a decimal representation
otherwise.
s S minimal state display (one character). See
section PROCESS STATE CODES for the
different values. See also stat if you want
additional information displayed. (alias
state).
sched SCH scheduling policy of the process. The
policies SCHED_OTHER (SCHED_NORMAL),
SCHED_FIFO, SCHED_RR, SCHED_BATCH,
SCHED_ISO, 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 lstart, bsdstart,
start_time, and stime.
start_time START starting time or date of the process. Only
the year will be displayed if the process
was not started the same year ps was
invoked, or "MmmDD" if it was not started
the same day, or "HH:MM" otherwise. See
also bsdstart, start, lstart, and stime.
stat STAT multi-character process state. See section
PROCESS STATE CODES for the different values
meaning. See also s and state if you just
want the first character displayed.
state S see s. (alias s).
suid SUID saved user ID. (alias svuid).
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 lwp, spid). 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).
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).
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).
wchan WCHAN name of the kernel function in which the
process is sleeping, a "-" if the process is
running, or a "*" if the process is
multi-threaded and ps is not displaying
threads.
ENVIRONMENT VARIABLES
The following environment variables could affect ps:
COLUMNS
Override default display width.
LINES
Override default display height.
PS_PERSONALITY
Set to one of posix, old, linux, bsd, sun, digital... (see
section PERSONALITY below).
CMD_ENV
Set to one of posix, old, linux, bsd, sun, digital... (see
section PERSONALITY below).
I_WANT_A_BROKEN_PS
Force obsolete command line interpretation.
LC_TIME
Date format.
PS_COLORS
Not currently supported.
PS_FORMAT
Default output format override. You may set this to a format
string of the type used for the -o option. The DefSysV and
DefBSD values are particularly useful.
POSIXLY_CORRECT
Don't find excuses to ignore bad "features".
POSIX2
When set to "on", acts as POSIXLY_CORRECT.
UNIX95
Don't find excuses to ignore bad "features".
_XPG
Cancel CMD_ENV=irix non-standard behavior.
In general, it is a bad idea to set these variables. The one
exception is CMD_ENV or PS_PERSONALITY, which could be set to
Linux for normal systems. Without that setting, ps follows the
useless and bad parts of the Unix98 standard.
PERSONALITY
390 like the 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
SEE ALSO
pgrep(1), pstree(1), top(1), proc(5).
STANDARDS
This ps conforms to:
1 Version 2 of the Single Unix Specification
2 The Open Group Technical Standard Base Specifications, Issue 6
3 IEEE Std 1003.1, 2004 Edition
4 X/Open System Interfaces Extension [UP XSI]
5 ISO/IEC 9945:2003
AUTHOR
ps was originally written by Branko Lankester ⟨lankeste@fwi.uva.
nl⟩. Michael K. Johnson ⟨johnsonm@redhat.com⟩ re-wrote it signif‐
icantly 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 for‐
eign syntax.
Please send bug reports to ⟨procps@freelists.org⟩. No subscrip‐
tion is required or suggested.
procps-ng 2018-08-08 PS(1)