ps - process status

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SYNOPSIS

DESCRIPTION

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 COMMAND which is running. The state is given by a sequence of three letters, e.g. ``RWN''. The first letter indicates the runnability of the process: R for runnable processes, U for uninterruptible processes, S for those sleeping for less than about 20 seconds, I for idle (sleeping longer than about 20 seconds), T for stopped processes, H for halted processes, P for processes in page wait, and D for those in disk (or other short term) waits, processes. The second letter indicates whether 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 requirements and which is exceeding that limit shows >; such a process is (necessarily) not swapped. The third letter indicates 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; processes running without special treatment have just a blank.

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 command 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 information.

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 terminals.

l

asks for a long listing, with fields PPID, CP, PRI, NI, ADDR, VSIZE, RSIZE and WCHAN as described below.

m

prints out the threads corresponding to each task.

n

asks for numerical output. In a long listing, the WCHAN field is printed numerically rather than symbolically, 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, co for console, da for ttyda, ? for processes with no tty, and ' a' or ' b' for ttya and ttyb respectively. This option must be the last one given.

u

A user oriented output is produced. This includes fields USER, %CPU, NICE, VSIZE, and RSIZE as described below.

v

A version of the output containing virtual memory statistics is output. This includes fields RE, SL, PAGEIN, VSIZE, RSIZE, LIM, TSIZ, TRS, %CPU and %MEM, described below. Because the NeXT computer is a Mach system (which doesn't necessarily record the same information as a UNIX 4.3BSD system) several of these fields will always be 0.

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

is a flag retained for backwards compatibility. This flag does nothing on the NeXT system.

#

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.

A second argument is taken to be the file containing the system's namelist. Otherwise, /mach is used.

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 setpriority.2

VSIZE

virtual size of the process (in bytes)

RSIZE

real memory (resident set) size of the process (in bytes)

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	00000001	in core
	SSYS	00000002	swapper or pager process
	SLOCK	00000004	process being swapped out
	SSWAP	00000008	save area flag
	STRC	00000010	process is being traced
	SWTED	00000020	another tracing flag
	SULOCK	00000040	user settable lock in core
	SPAGE	00000080	process in page wait state
	SKEEP	00000100	another flag to prevent swap out
	SOMASK	00000200	restore old mask after taking signal
	SWEXIT	00000400	working on exiting
	SPHYSIO	00000800	doing physical i/o
	SVFORK	00001000	process resulted from vfork()
	SVFDONE	00002000	another vfork flag
	SNOVM	00004000	no vm, parent in a vfork()
	SPAGI	00008000	init data space on demand from inode
	SSEQL	00010000	user warned of sequential vm behavior
	SUANOM	00020000	user warned of anomalous vm behavior
	STIMO	00040000	timing out during sleep
	SACTIVE	00080000	process is executing
	SOUSIG	00100000	using old signal mechanism
	SOWEUPC	00200000	owe process and addupc() call at next ast
	SSEL	00400000	selecting; wakeup/waiting danger
	SLOGIN	00800000	a login process (legitimate child of init)
	SLKDONE	20000000	record-locking has been done

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

SEE ALSO

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Created by unroff & hp-tools. © somebody (See intro for details). All Rights Reserved. Last modified 11/5/97