PS(1)

NAME
ps - process status

SYNOPSIS
ps [ acgklrstuvwx# [ namelist ] ]

DESCRIPTION
Ps prints certain indicia about active processes. To get a complete printout on the console or lpr, use ``ps axlgw'' For a quick snapshot of system activity, ``ps au'' is recommended. A minus may precede options with no effect. The following options may be specified.

a   asks for information about all processes with terminals (ordinarily only one's own processes are displayed).

c   causes only the comm field to be displayed instead of the arguments. (The comm field is the tail of the path name of the file the process last exec'ed.) This option speeds up ps somewhat and reduces the amount of output. It is also more reliable since the process can't scribble on top of it.

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, or if their arguments begin with a `-'. This normally eliminates shells and getty processes.

k   causes the file /vmcore is used in place of /dev/kmem and /dev/mem. This is used for postmortem system debugging.

l   asks for a long listing. The short listing contains the user name, process ID, tty, the cumulative execution time of the process and an approximation to the command line.

r   asks for "raw output". A non-human readable sequence of structures is output on the standard output. There is one structure for each process, the format is defined by <psout.h>

s   Print the size of the kernel stack of each process. This may only be used with the short listing, and is for use by system developers.

tttyname
    restricts output to processes whose controlling tty is the specified ttyname (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, etc). This option must be the last one given.

u   A user oriented output is produced. This includes the name of the owner of the process, process id, percent of the CPU recently used (not yet implemented), nice value, size, resident set size, tty, cpu time used, and the command.

v   A version of the output containing virtual memory statistics is output. Fields output are flags, process id, teletype, cpu time, residency time, time sleeping, minor page faults, major page faults, process virtual size, resident set size, size of resident set at last swap, text virtual size, text resident set size, the average number of page faults per second over the last few seconds, and the command. Flags are R for running, S for sleeping, W for swapped, D for disk (i/o) wait, and P for page wait. Residency time is the length of time in core or on disk; currently ``127'' is infinite. Resident size is the number of physical memory pages assigned.

w   tells ps you are on a wide terminal (132 columns). Ps normally assumes you are on an 80 column terminal. This information is used to decide how much of long commands to print. The w option may be repeated, e.g. ww, and the entire command, up to 128 characters, will be printed without regard to terminal width.

x   asks even about processes with no terminal.

#   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 tells ps where to look for core if the k option is given, instead of /vmcore. A third argument is the name of a swap file to use instead of the default /dev/drum. If a fourth argument is given, it is taken to be the file containing the system's namelist. Otherwise, "/vmunix" is used.

The output is sorted by tty, then by process ID.

The long listing is columnar and contains

F   Flags associated with the process. These are defined by #define lines in /usr/include/sys/proc.h.

S   The state of the process. 0: nonexistent; S: sleeping; W: waiting; R: running; I: intermediate; Z: terminated; T: stopped.

UID The user id of the process owner.

PID The process ID of the process; as in certain cults it is possible to kill a process if you know its true name.

PPID
    The process ID of the parent process.

CPU Processor utilization for scheduling.

PRI The priority of the process; high numbers mean low priority.

NICE
    Used in priority computation.

ADDR
    The memory address of the process if resident, otherwise the disk address.

SZ  The size in blocks of the memory image of the process.

RSS The size of the resident set (set of pages that the process can access without faulting) of the process.

WCHAN
    The event for which the process is waiting or sleeping; if blank, the process is running.

TTY The controlling tty for the process.

TIME
    The cumulative execution time for the process.

COMMAND
    The command and its arguments.

A process that has exited and has a parent, but has not yet been waited for by the parent is marked <defunct>. 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
/vmunix    system namelist
/dev/kmem    kernel memory
/dev/drum    swap device
/vmcore    core file
/dev    searched to find swap device and tty names

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.

Some processes, typically those in the background, are printed with null or garbaged arguments, even though the process has not swapped. (Sometimes ps even loses on its own arguments!) In these cases, the name of the command is printed in parentheses.