ps

The ps utility shall write information about processes, subject to having appropriate privileges to obtain information about those processes. By default, ps shall select all processes with the same effective user ID as the current user and the same controlling terminal as the invoker. Write information for all processes associated with terminals. Implementations may omit session leaders from this list. [XSI) ] ![[Option Start]]( Write information for all processes, except session leaders. ![[Option End]]( [XSI) ] ![[Option Start]]( Generate a full listing. (See the STDOUT section for the contents of a full listing.) ![[Option End]]( [XSI) ] ![[Option Start]]( Write information for processes whose session leaders are given in grouplist . The application shall ensure that the grouplist is a single argument in the form of a or -separated list. ![[Option End]]( [XSI) ] ![[Option Start]]( Generate a long listing. (See STDOUT for the contents of a long listing.) ![[Option End]]( [XSI) ] ![[Option Start]]( Specify the name of an alternative system namelist file in place of the default. The name of the default file and the format of a namelist file are unspecified. ![[Option End]]( Write information according to the format specification given in format . This is fully described in the STDOUT section. Multiple -o options can be specified; the format specification shall be interpreted as the -separated concatenation of all the format option-arguments. Override the system-selected horizontal display line size, used to determine the number of text columns to display. See XBD Environment Variables for valid values and results when it is unset or null. Provide a default value for the internationalization variables that are unset or null. (See XBD Internationalization Variables the precedence of internationalization variables used to determine the values of locale categories.) If set to a non-empty string value, override the values of all the other internationalization variables. Determine the locale that should be used to affect the format and contents of diagnostic messages written to standard error and informative messages written to standard output. Determine the format and contents of the date and time strings displayed. [XSI) ] ![[Option Start]]( Determine the location of message catalogs for the processing of LC MESSAGES. ![[Option End]]( When the -o option is not specified, the standard output format is unspecified. [XSI) ] ![[Option Start]]( On XSI-conformant systems, the output format shall be as follows. The column headings and descriptions of the columns in a ps listing are given below. The precise meanings of these fields are implementation-defined. The letters 'f' and 'l' (below) indicate the option ( full or long ) that shall cause the corresponding heading to appear; all means that the heading always appears. Note that these two options determine only what information is provided for a process; they do not determine which processes are listed. A process that has exited and has a parent, but has not yet been waited for by the parent, shall be marked defunct . Under the option -f , ps tries to determine the command name and arguments given when the process was created by examining memory or the swap area. Failing this, the command name, as it would appear without the option -f , is written in square brackets. ![[Option End]]( The -o option allows the output format to be specified under user control. The decimal value of the nice value of the process; see nice . The name of the controlling terminal of the process (if any) in the same format used by the who utility. Only comm and args shall be allowed to contain characters; all others shall not. Any implementation-defined variables shall be specified in the system documentation along with the default header and indicating whether the field may contain characters. The following table specifies the default header to be used in the POSIX locale corresponding t