PS(C) UNIX System V
Name
ps - reports process status
Syntax
ps [ options ]
Description
ps prints certain information about active processes.
Entering ps without any options calls up information about
processes associated with the current terminal. The
following options control the amount and type of information
displayed.
Options
-e Prints information about all processes.
-d Prints information about all processes, except
process group leaders.
-a Prints information about all processes, except
process group leaders and processes not
associated with a terminal.
-f Generates a full listing. Normally, a short
listing containing only process ID, terminal
(``tty'') identifier, cumulative execution time,
and the command name is printed. Under the -f
option, ps tries to determine and print the
process' original command name and arguments.
If it cannot, it prints the short listing
version of the command name within square
brackets. See below for the meaning of columns
in a full listing.
-l Generates a long listing, including status,
priority, location, and memory usage information
for each process.
-t tlist Restricts listing to data about the processes
associated with the terminals given in tlist,
where tlist can be in one of two forms: a list
of terminal identifiers separated from one
another by a comma, or a list of terminal
identifiers enclosed in double quotes and
separated from one another by a comma and/or one
or more spaces.
-p plist Restricts listing to data about processes whose
process ID numbers are given in plist, where
plist is in the same format as tlist.
-u ulist Restricts listing to data about processes whose
user ID numbers or login names are given in
ulist, where ulist is in the same format as
tlist. In the listing, the numerical user ID is
printed unless the -f option is used, in which
case the login name is printed.
-g glist Restricts listing to data about processes whose
process groups are given in glist, where glist
is a list of process group leaders and is in the
same format as tlist.
-s swapdev Uses the file swapdev in place of /dev/swap.
This is useful when examining a corefile.
-n namelist The argument is taken as the name of an
alternate namelist (/unix is the default).
Display Columns
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) that causes the corresponding heading
to appear; all means that the heading always appears. Note
that these two options only determine what information is
provided for a process; they do not determine which
processes will be listed.
F (l)
A status word consisting of flags associated
with the process. Each flag is associated
with a bit in the status word. These flags
are added to form a single octal number.
Process flag bits and their meanings are:
01 in core;
02 system process;
04 locked in core (e.g., for physical
I/O);
10 being swapped;
20 being traced by another process.
S (l)
The state of the process:
0 non-existent;
S sleeping;
R running;
I intermediate;
Z terminated;
T stopped;
B waiting.
UID (f,l)
The user ID number of the process owner; the login name is
printed under the -f option. Login names are truncated
after 7 characters.
PID (all)
The process ID; used when killing a process (see kill(C)).
PPID (f,l)
The process ID of the parent process.
C (f,l)
Processor utilization for scheduling.
STIME (f)
Starting time of the process.
PRI (l)
The priority of the process; higher numbers mean lower
priority.
NI (l)
Nice value; used in priority computation.
ADDR1,
ADDR2 (l)
The memory addresses (physical page frame numbers) of u-area
of the process, if resident; otherwise, the disk address.
ADDR1 gives the frame number of the first half of the u-
area, and ADDR2 gives the number of the second half.
SZ (l)
The size in blocks of the core image of the process, but not
including the size of text shared with other processes.
Since this size includes the current size of the stack, it
will vary as the stack size varies.
WCHAN (l)
The event for which the process is waiting or sleeping; if
blank, the process is running.
TTY (all)
The controlling terminal for the process.
TIME (all)
The cumulative execution time for the process.
CMD (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
/unix system namelist
/dev/mem memory
/dev searched to find swap device and terminal
(``tty'') names.
See Also
kill(C), nice(C)
Notes
Things can change while ps is running; the picture it gives
is only a close approximation to reality.
Some data printed for defunct processes are irrelevant.
Authorization
The behavior of this utility is affected by assignment of
the mem authorization, which is usually reserved for system
administrators. If you do not have this authorization, the
output will be restricted to data pertaining to your
activities only. Refer to the ``Using a Trusted System''
chapter of the User's Guide for more details.
Standards Conformance
ps is conformant with:
AT&T SVID Issue 2, Select Code 307-127;
and The X/Open Portability Guide II of January 1987.
(printed 2/15/90) PS(C)