ps(1) INTERACTIVE UNIX System ps(1)
NAME
ps - report process status
SYNOPSIS
ps [options]
DESCRIPTION
ps prints certain information about active processes.
Without options, information is printed about processes
associated with the controlling terminal. Output consists
of a short listing containing only the process ID, terminal
identifier, cumulative execution time, and the command name.
Otherwise, the information that is displayed is controlled
by the selection of options.
Options accept names or lists as arguments. Arguments can
be either separated from one another by commas or enclosed
in double quotes and separated from one another by commas or
spaces. Values for proclist and grplist must be numeric.
The options are given in descending order according to
volume and range of information provided:
-e Print information about every process now run-
ning.
-d Print information about all processes except
process group leaders.
-a Print information about all processes most fre-
quently requested: all those except process
group leaders and processes not associated with
a terminal.
-f Generate a full listing. (See below for signi-
ficance of columns in a full listing.)
-l Generate a long listing. (See the following
text.)
-n name Valid only for users with a real user id of root
or a real group id of sys. Takes argument sig-
nifying an alternate system name in place of
/unix.
-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 process group
leader's ID number(s) appears in grplist. (A
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ps(1) INTERACTIVE UNIX System ps(1)
group leader is a process whose process ID
number is identical to its process group ID
number. A login shell is a common example of a
process group leader.)
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 in the following text; 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 deter-
mine 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.
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ps(1) INTERACTIVE UNIX System ps(1)
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).
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.
PRI (l) The priority of the process (higher numbers
mean lower priority).
NI (l) Nice value, used in priority computation.
ADDR (l) The physical memory address of the first
page of the user block. If the user block
is swapped out, ADDR is shown as 0.
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
/dev/sxt/*
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ps(1) INTERACTIVE UNIX System ps(1)
/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/ps_data internal data structure
/unix system name list
SEE ALSO
getty(1M), kill(1), nice(1).
WARNING
Things can change while ps is running; the snap-shot it
gives is only true 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(2) 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.
ADDED VALUE
This entry, supplied by INTERACTIVE Systems Corporation,
contains enhancements to UNIX System V.
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