ps(1) USER COMMANDS ps(1)
NAME
ps - report process status
SYNOPSIS
ps [ options ]
DESCRIPTION
ps prints information about active processes. Without
options, ps prints information about processes associated
with the controlling terminal. The output contains only the
process ID, terminal identifier, cumulative execution time,
and the command name. Otherwise, the information that is
displayed is controlled by the options.
Some options accept lists as arguments. Items in a list can
be either separated by commas or else enclosed in double
quotes and separated by commas or spaces. Values for pro-
clist and grplist must be numeric.
The options are:
-e Print information about every process now run-
ning.
-d Print information about all processes except
session leaders.
-a Print information about all processes most fre-
quently requested: all those except process
group leaders and processes not associated with
a terminal.
-j Print session ID and process group ID.
-f Generate a full listing. (See below for signi-
ficance of columns in a full listing.)
-l Generate a long listing. (See below.)
-c Print information in a format that reflects
scheduler properties as described in
priocntl(1). The -c option affects the output
of the -f and -l options, as described below.
-t termlist List only process data associated with the ter-
minal given in termlist. Terminal identifiers
may be specified in one of two forms: the
device's file name (e.g., tty04) or, if the
device's file name starts with tty, just the
digit identifier (e.g., 04).
-p proclist List only process data whose process ID numbers
are given in proclist.
-u uidlist List only process data whose user ID number or
login name is given in uidlist. In the listing,
the numerical user ID will be printed unless you
give the -f option, which prints the login name.
-g grplist List only process data whose group leader's ID
number(s) appears in grplist. (A group leader
is a process whose process ID number is
1
ps(1) USER COMMANDS ps(1)
identical to its process group ID number.
-s sesslist List information on all session leaders whose
IDs appear in sesslist.
Under the -f option, ps tries to determine the command name
and arguments given when the process was created by examin-
ing the user block. Failing this, the command name is
printed, as it would have appeared without the -f option, in
square brackets.
The column headings and the meaning of the columns in a ps
listing are given below; the letters f and l indicate the
option (full or long, respectively) that causes the
corresponding heading to appear; all means that the heading
always appears. Note that these two options determine only
what information is provided for a process; they do not
determine which processes will be listed.
F (l) Flags (hexadecimal and additive) associated
with the process
00 Process has terminated: process
table entry now available.
01 A system process: always in primary
memory.
02 Parent is tracing process.
04 Tracing parent's signal has stopped
process: parent is waiting
[ptrace(2)].
08 Process is currently in primary
memory.
10 Process currently in primary
memory: locked until an event com-
pletes.
S (l) The state of the process:
O Process is running on a processor.
S Sleeping: process is waiting for an
event to complete.
R Runnable: process is on run queue.
I Idle: process is being created.
Z Zombie state: process terminated
and parent not waiting.
T Traced: process stopped by a signal
because parent is tracing it.
X SXBRK state: process is waiting for
more primary memory.
UID (f,l) The user ID number of the process owner
(the login name is printed under the -f
option).
2
ps(1) USER COMMANDS ps(1)
PID (all) The process ID of the process (this datum
is necessary in order to kill a process).
PPID (f,l) The process ID of the parent process.
C (f,l) Processor utilization for scheduling. Not
printed when the -c option is used.
CLS (f,l) Scheduling class. Printed only when the -c
option is used.
PRI (l) The priority of the process. Without the
-c option, higher numbers mean lower prior-
ity. With the -c option, higher numbers
mean higher priority.
NI (l) Nice value, used in priority computation.
Not printed when the -c option is used.
Only processes in the time-sharing class
have a nice value.
ADDR (l) The memory address of the process.
SZ (l) The size (in pages or clicks) of the swap-
pable process's image in main memory.
WCHAN (l) The address of an event for which the pro-
cess is sleeping, or in SXBRK state, (if
blank, the process is running).
STIME (f) The starting time of the process, given in
hours, minutes, and seconds. (A process
begun more than twenty-four hours before
the ps inquiry is executed is given in
months and days.)
TTY (all) The controlling terminal for the process
(the message, ?, is printed when there is
no controlling terminal).
TIME (all) The cumulative execution time for the pro-
cess.
COMMAND(all) The command name (the full command name and
its arguments are printed under the -f
option).
A process that has exited and has a parent, but has not yet
been waited for by the parent, is marked <defunct>.
FILES
/dev
3
ps(1) USER COMMANDS ps(1)
/dev/sxt/*
/dev/tty*
/dev/xt/* terminal (``tty'') names searcher files
/dev/kmem kernel virtual memory
/dev/swap the default swap device
/dev/mem memory
/etc/passwd UID information supplier
/etc/psdata internal data structure
SEE ALSO
kill(1), nice(1), priocntl(1).
getty(1M) in the System Administrator's Reference Manual.
NOTES
Things can change while ps is running; the snap-shot it
gives is true only for a split-second, and it may not be
accurate by the time you see it. Some data printed for
defunct processes is irrelevant.
If no termlist, proclist, uidlist, or grplist is specified,
ps checks stdin, stdout, and stderr in that order, looking
for the controlling terminal and will attempt to report on
processes associated with the controlling terminal. In this
situation, if stdin, stdout, and stderr are all redirected,
ps will not find a controlling terminal, so there will be no
report.
On a heavily loaded system, ps may report an lseek error and
exit. ps may seek to an invalid user area address: having
obtained the address of a process' user area, ps may not be
able to seek to that address before the process exits and
the address becomes invalid.
ps -ef may not report the actual start of a tty login ses-
sion, but rather an earlier time, when a getty was last
respawned on the tty line.
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