PS(1-BSD) RISC/os Reference Manual PS(1-BSD)
NAME
ps - process status
SYNOPSIS
ps [ aceglnstuvwxU# ]
DESCRIPTION
ps prints information about processes. Normally, only your
processes are candidates to be printed by ps; specifying a
causes other users' processes to be candidates to be
printed; specifying x includes processes without control
terminals in the candidate pool.
All output formats include, for each process, the process id
PID, control terminal of the process TT, cpu time used by
the process TIME (this includes both user and system time),
the state STAT of the process, and an indication of the COM-
MAND which is running. The state is given by a sequence of
letters, e.g. ``RWNA''. The first letter indicates the run-
nability of the process: R for runnable processes, T for
stopped processes, P for processes in page wait, D for those
in disk (or other short term) waits, S for those sleeping
for less than about 20 seconds, and I for idle (sleeping
longer than about 20 seconds) processes. Additional charac-
ters after these, if any, indicate additional state informa-
tion. The letter W indicates that a process is swapped out,
showing W if it is, or a blank if it is loaded (in-core). A
process which has specified a soft limit on memory require-
ments and which is exceeding that limit shows >; such a pro-
cess is (necessarily) not swapped. An additional letter may
indicate whether a process is running with altered CPU
scheduling priority (nice); if the process priority is
reduced, an N is shown, if the process priority has been
artificially raised then a `<' is shown. The final optional
letter indicates any special treatment of the process for
virtual memory replacement; the letters correspond to
options to the vadvise(2) call; currently the possibilities
are A standing for VA_ANOM and S for VA_SEQL. S is typical
of large image processing programs which are using virtual
memory to sequentially address voluminous data.
Here are the options:
a asks for information about all processes with terminals
(ordinarily only one's own processes are displayed).
c prints the command name, as stored internally in the
system for purposes of accounting, rather than the com-
mand arguments, which are kept in the process' address
space. This is more reliable, if less informative,
since the process is free to destroy the latter infor-
mation.
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e Asks for the environment to be printed as well as the
arguments to the command.
g Asks for all processes. Without this option, ps only
prints ``interesting'' processes. Processes are deemed
to be uninteresting if they are process group leaders.
This normally eliminates top-level command interpreters
and processes waiting for users to login on free termi-
nals.
l asks for a long listing, with fields PPID, CP, PRI, NI,
ADDR, SIZE, and WCHAN as described below.
n Asks for numerical output. In a long listing, the
WCHAN field is printed numerically rather than symboli-
cally, or, in a user listing, the USER field is
replaced by a UID field.
s Adds the size SSIZ of the kernel stack of each process
(for use by system maintainers) to the basic output
format.
tx restricts output to processes whose controlling tty is
x (which should be specified as printed by ps, e.g. t3
for tty3, tco for console, td0 for ttyd0, t? for
processes with no tty, t for processes at the current
tty, etc). This option must be the last one given.
u A user oriented output is produced. This includes
fields USER, %CPU, NICE, SIZE, and RSS as described
below.
v A version of the output containing virtual memory
statistics is output. This includes fields RE, SL,
PAGEIN, SIZE, RSS, LIM, and %MEM, described below.
w Use a wide output format (132 columns rather than 80);
if repeated, e.g. ww, use arbitrarily wide output.
This information is used to decide how much of long
commands to print.
x asks even about processes with no terminal.
U causes ps to update a private database where it keeps
system information. Thus ``ps U'' should be included
in the /etc/rc file.
# A process number may be given, (indicated here by #),
in which case the output is restricted to that process.
This option must also be last.
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Fields which are not common to all output formats:
USER name of the owner of the process
%CPU 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%.
NICE (or NI) process scheduling increment (see setprior-
ity(2))
SIZE virtual size of the process (in 1024 byte units)
RSS real memory (resident set) size of the process (in 1024
byte units)
LIM soft limit on memory used, specified via a call to
setrlimit(2); if no limit has been specified then shown
as xx
TSIZ size of text (shared program) image
TRS size of resident (real memory) set of text
%MEM percentage of real memory used by this process.
RE residency time of the process (seconds in core)
SL sleep time of the process (seconds blocked)
PAGEIN
number of disk i/o's resulting from references by the
process to pages not loaded in core.
UID numerical user-id of process owner
PPID numerical id of parent of process
CP short-term cpu utilization factor (used in scheduling)
PRI process priority (non-positive when in non-
interruptible wait)
ADDR swap address of the process
WCHAN
event on which process is waiting (an address in the
system). A symbol is chosen that classifies the
address, unless numerical output is requested (see the
n flag). In this case, the initial part of the address
is trimmed off and is printed hexadecimally, e.g.,
0x80004000 prints as 4000.
F flags associated with process as in <sys/proc.h>:
SLOAD 000001 in core
SSYS 000002 swapper or pager process
SLOCK 000004 process being swapped out
SSWAP 000008 save area flag
STRC 000010 process is being traced
SWTED 000020 another tracing flag
SULOCK 000040 user settable lock in core
SPAGE 000080 process in page wait state
SKEEP 000100 another flag to prevent swap out
SDLYU 000200 delayed unlock of pages
SWEXIT 000400 working on exiting
SPHYSIO 000800 doing physical i/o (bio.c)
SVFORK 001000 process resulted from vfork()
SVFDONE 002000 another vfork flag
SNOVM 004000 no vm, parent in a vfork()
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SPAGI 008000 init data space on demand from inode
SANOM 010000 system detected anomalous vm behavior
SUANOM 020000 user warned of anomalous vm behavior
STIMO 040000 timing out during sleep
SDETACH 080000 detached inherited by init
SOUSIG 100000 using old signal mechanism
A process that has exited and has a parent that has not yet
waited for the process is marked <defunct>; a process which
is blocked trying to exit is marked <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 counted on too much.
FILES
/unix system namelist
/dev/kmem kernel memory
/dev searched to find swap device and tty names
/etc/ps_data system namelist, device, and wait channel
information
SEE ALSO
kill(1), w(1).
BUGS
Things can change while ps is running; the picture it gives
is only a close approximation to reality.
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