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PS
!!!PS
NAME
SYNOPSIS
DESCRIPTION
OPTIONS
NOTES
SORT KEYS
AIX FORMAT DESCRIPTORS
STANDARD FORMAT SPECIFIERS
ENVIRONMENT VARIABLES
EXAMPLES
CONFORMING TO
AUTHOR
SEE ALSO
----
!!NAME


__ps__ - report process status
!!SYNOPSIS


__ps__ [[''options'']
!!DESCRIPTION


__ps__ gives a snapshot of the current processes. If you
want a repetitive update of this status, use __top__.
This man page documents the /proc-based version of
__ps__, or tries to.
!!OPTIONS


This version of __ps__ accepts several kinds of
options.


Unix options may be grouped and must be preceeded by a dash.
BSD options may be grouped and must not be used with a dash.
GNU long options are preceeded by two dashes.


Options of different types may be freely mixed.


Set the __I_WANT_A_BROKEN_PS__ environment variable to
force BSD syntax even when options are preceeded by a dash.
The __PS_PERSONALITY__ environment variable (described
below) provides more detailed control of ps
behavior.


SIMPLE PROCESS SELECTION


PROCESS SELECTION BY LIST


OUTPUT FORMAT CONTROL


OUTPUT MODIFIERS


INFORMATION


OBSOLETE
!!NOTES


The __-g__ option can select by session leader OR by group name. Selection by session leader is specified by many standards, but selection by group is the logical behavior that several other operating systems use. This ps will select by session leader when the list is completely numeric (as sessions are). Group ID numbers will work only when some group names are also specified.


The __m__ option should not be used. Use __-m__ or
__-o__ with a list. (__m__ displays memory info, shows
threads, or sorts by memory use)


The __h__ option is problematic. Standard BSD __ps__
uses the option to print a header on each page of output,
but older Linux __ps__ uses the option to totally disable
the header. This version of ps follows the Linux usage of
not printing the header unless the BSD personality has been
selected, in which case it prints a header on each page of
output. Regardless of the current personality, you can use
the long options __--headers__ and __--no-headers__ to
enable printing headers each page and disable headers
entirely, respectively.


Terminals (ttys, or screens for text output) can be
specified in several forms: ''/dev/ttyS1'', ''ttyS1'',
''S1''. Obsolete __ps t__ (your own terminal) and
__ps t?__ (processes without a terminal) syntax is
supported, but modern options (__T__, __-t__ with
list, __x__, __t__ with list) should be used
instead.


The BSD __O__ option can act like __-O__ (user-defined
output format with some common fields predefined) or can be
used to specify sort order. Heuristics are used to determine
the behavior of this option. To ensure that the desired
behavior is obtained, specify the other option (sorting or
formatting) in some other way.


For sorting, BSD __O__ option syntax is
__O__[[+|-]''k1''[[,[[+|-]''k2''[[,...]] Order the
process listing according to the multilevel sort specified
by the sequence of short keys from SORT KEYS, ''k1'',
''k2'', ... The `+' is quite optional, merely
re-iterating the default direction on a key. `-' reverses
direction only on the key it precedes. The __O__ option
must be the last option in a single command argument, but
specifications in successive arguments are
catenated.


GNU sorting syntax is
__--sort__''X''[[+|-]''key''[[,[[+|-]''key''[[,...]]
Choose a multi-letter key from the SORT KEYS section. X may
be any convenient separator character. To be GNU-ish use
`='. The `+' is really optional since default direction is
increasing numerical or lexicographic order. For example,
__ps__ ''jax''
__--sort__=''uid'',-''ppid'',+''pid''


This __ps__ works by reading the virtual files in /proc.
This __ps__ does not need to be suid kmem or have any
privileges to run. Do not give this __ps__ any special
permissions.


This __ps__ needs access to a namelist file for proper
WCHAN display. The namelist file must match the current
Linux kernel exactly for correct output.


To produce the WCHAN field, ps needs to read the System.map
file created when the kernel is compiled. The search path
is:


__$PS_SYSTEM_MAP__''
/boot/System.map-`uname -r`
/boot/System.map
/lib/modules/`uname -r`/System.map
/usr/src/linux/System.map''


The member used_math of task_struct is not shown, since
crt0.s checks to see if math is present. This causes the
math flag to be set for all processes, and so it is
worthless. (Somebody fix libc or the kernel
please)


Programs swapped out to disk will be shown without command
line arguments, and unless the __c__ option is given, in
brackets.


%CPU shows the cputime/realtime percentage. It will not add
up to 100% unless you are lucky. It is time used divided by
the time the process has been running.


The SIZE and RSS fields don't count the page tables and the
task_struct of a proc; this is at least 12k of memory that
is always resident. SIZE is the virtual size of the proc
(code+data+stack).


Processes marked
init__(8) if the parent process
exits.


PROCESS FLAGS


PROCESS STATE CODES


For BSD formats and when the
!!SORT KEYS


Note that the values used in sorting are the internal values ps uses and not the `cooked' values used in some of the output format fields. Pipe ps output into the sort(1) command if you want to sort the cooked values.
!!AIX FORMAT DESCRIPTORS


This ps supports AIX format descriptors, which work somewhat like the formatting codes of printf(1) and printf(3). For example, the normal default output can be produced with this: __ps -eo__ __
!!STANDARD FORMAT SPECIFIERS


These may be used to control both output format and sorting. For example: ps -eo pid,user,args --sort user
!!ENVIRONMENT VARIABLES


The following environment variables could affect ps:


In general, it is a bad idea to set these variables. The one exception is __CMD_ENV__ or __PS_PERSONALITY__, which could be set to Linux for normal systems. Without that setting, __ps__ follows the useless and bad parts of the Unix98 standard.


PERSONALITY
!!EXAMPLES


To see every process on the system using standard syntax: __ps -e__
To see every process on the system using BSD syntax: __ps ax__
To see every process except those running as root (real ps -U__ ''root'' __-u__ ''root'' __-N__
To see every process with a user-defined format: __ps -eo__ pid,tt,user,fname,tmout,f,wchan
Odd display with AIX field descriptors: __ps -o__ __
Print only the process IDs of syslogd: __ps -C__ ''syslogd'' __-o__ pid=
!!CONFORMING TO


This __ps__ conforms to version 2 of the Single Unix
Specification.
!!AUTHOR


ps was originally written by Branko Lankester
ps__ for full
Unix98 and BSD support, along with some ugly hacks for
obsolete and foreign syntax.


Please send bug reports to
!!SEE ALSO


top(1), pstree(1), proc(5)
----
33 pages link to ps(1):
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Last edited on Tuesday, June 4, 2002 12:22:47 am by "perry"
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