1 This is what POSIX 2003 says about ps:
3 By default, ps shall select all processes with the same effective user
4 ID as the current user and the same controlling terminal as the invoker
6 ps [-aA][-defl][-G grouplist][-o format]...[-p proclist][-t termlist]
7 [-U userlist][-g grouplist][-n namelist][-u userlist]
9 -a Write information for all processes associated with terminals.
10 Implementations may omit session leaders from this list.
12 -A Write information for all processes.
14 -d Write information for all processes, except session leaders.
16 -e Write information for all processes. (Equivalent to -A.)
18 -f Generate a full listing. (See the STDOUT section for the con-
19 tents of a full listing.)
22 Write information for processes whose session leaders are given
23 in grouplist. The application shall ensure that the grouplist is
24 a single argument in the form of a <blank> or comma-separated
28 Write information for processes whose real group ID numbers are
29 given in grouplist. The application shall ensure that the grou-
30 plist is a single argument in the form of a <blank> or comma-
33 -l Generate a long listing. (See STDOUT for the contents of a long
37 Specify the name of an alternative system namelist file in place
38 of the default. The name of the default file and the format of a
39 namelist file are unspecified.
42 Write information according to the format specification given in
43 format. Multiple -o options can be specified; the format speci-
44 fication shall be interpreted as the <space>-separated concate-
45 nation of all the format option-arguments.
48 Write information for processes whose process ID numbers are
49 given in proclist. The application shall ensure that the pro-
50 clist is a single argument in the form of a <blank> or comma-
54 Write information for processes associated with terminals given
55 in termlist. The application shall ensure that the termlist is a
56 single argument in the form of a <blank> or comma-separated
57 list. Terminal identifiers shall be given in an implementation-
58 defined format. On XSI-conformant systems, they shall be
59 given in one of two forms: the device's filename (for example,
60 tty04) or, if the device's filename starts with tty, just the
61 identifier following the characters tty (for example, "04" ).
64 Write information for processes whose user ID numbers or login
65 names are given in userlist. The application shall ensure that
66 the userlist is a single argument in the form of a <blank> or
67 comma-separated list. In the listing, the numerical user ID
68 shall be written unless the -f option is used, in which case the
69 login name shall be written.
72 Write information for processes whose real user ID numbers or
73 login names are given in userlist. The application shall ensure
74 that the userlist is a single argument in the form of a <blank>
75 or comma-separated list.
77 With the exception of -o format, all of the options shown are used to
78 select processes. If any are specified, the default list shall be
79 ignored and ps shall select the processes represented by the inclusive
80 OR of all the selection-criteria options.
82 The -o option allows the output format to be specified under user con-
85 The application shall ensure that the format specification is a list of
86 names presented as a single argument, <blank> or comma-separated. Each
87 variable has a default header. The default header can be overridden by
88 appending an equals sign and the new text of the header. The rest of
89 the characters in the argument shall be used as the header text. The
90 fields specified shall be written in the order specified on the command
91 line, and should be arranged in columns in the output. The field widths
92 shall be selected by the system to be at least as wide as the header
93 text (default or overridden value). If the header text is null, such as
94 -o user=, the field width shall be at least as wide as the default
95 header text. If all header text fields are null, no header line shall
98 ruser The real user ID of the process. This shall be the textual user
99 ID, if it can be obtained and the field width permits, or a dec-
100 imal representation otherwise.
102 user The effective user ID of the process. This shall be the textual
103 user ID, if it can be obtained and the field width permits, or a
104 decimal representation otherwise.
106 rgroup The real group ID of the process. This shall be the textual
107 group ID, if it can be obtained and the field width permits, or
108 a decimal representation otherwise.
110 group The effective group ID of the process. This shall be the textual
111 group ID, if it can be obtained and the field width permits, or
112 a decimal representation otherwise.
114 pid The decimal value of the process ID.
116 ppid The decimal value of the parent process ID.
118 pgid The decimal value of the process group ID.
120 pcpu The ratio of CPU time used recently to CPU time available in the
121 same period, expressed as a percentage. The meaning of
122 "recently" in this context is unspecified. The CPU time avail-
123 able is determined in an unspecified manner.
125 vsz The size of the process in (virtual) memory in 1024 byte units
126 as a decimal integer.
128 nice The decimal value of the nice value of the process; see nice() .
130 etime In the POSIX locale, the elapsed time since the process was
131 started, in the form: [[dd-]hh:]mm:ss
133 time In the POSIX locale, the cumulative CPU time of the process in
134 the form: [dd-]hh:mm:ss
136 tty The name of the controlling terminal of the process (if any) in
137 the same format used by the who utility.
139 comm The name of the command being executed ( argv[0] value) as a
142 args The command with all its arguments as a string. The implementa-
143 tion may truncate this value to the field width; it is implemen-
144 tation-defined whether any further truncation occurs. It is
145 unspecified whether the string represented is a version of the
146 argument list as it was passed to the command when it started,
147 or is a version of the arguments as they may have been modified
148 by the application. Applications cannot depend on being able to
149 modify their argument list and having that modification be
150 reflected in the output of ps.
152 Any field need not be meaningful in all implementations. In such a case
153 a hyphen ( '-' ) should be output in place of the field value.
155 Only comm and args shall be allowed to contain <blank>s; all others
158 The following table specifies the default header to be used in the
159 POSIX locale corresponding to each format specifier.
161 Format Specifier Default Header Format Specifier Default Header
162 args COMMAND ppid PPID
163 comm COMMAND rgroup RGROUP
164 etime ELAPSED ruser RUSER
165 group GROUP time TIME
171 There is no special quoting mechanism for header text. The header text
172 is the rest of the argument. If multiple header changes are needed,
173 multiple -o options can be used, such as:
175 ps -o "user=User Name" -o pid=Process\ ID