ps - Environment Variables (Continued), Personality Settings, Bugs, See Also, Standards, and Author

This is equivalent to selecting ‐‐ppid 2 ‐p 2 ‐‐deselect instead. Also works in BSD mode. PS_COLORS Not currently supported. PS_FORMAT Default output format override. You may set this to a format string of the type used for the -o option. The DefSysV and DefBSD values are particularly useful. POSIXLY_CORRECT Don’t find excuses to ignore bad "features". POSIX2 When set to "on", acts as POSIXLY_CORRECT. UNIX95 Don’t find excuses to ignore bad "features". _XPG Cancel CMD_ENV=irix non-standard behavior. 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 390 like the OS/390 OpenEdition ps aix like AIX ps bsd like FreeBSD ps (totally non-standard) compaq like Digital Unix ps debian like the old Debian ps digital like Tru64 (was Digital Unix, was OSF/1) ps gnu like the old Debian ps hp like HP-UX ps hpux like HP-UX ps irix like Irix ps linux ***** recommended ***** old like the original Linux ps (totally non-standard) os390 like OS/390 Open Edition ps posix standard s390 like OS/390 Open Edition ps sco like SCO ps sgi like Irix ps solaris2 like Solaris 2+ (SunOS 5) ps sunos4 like SunOS 4 (Solaris 1) ps (totally non-standard) svr4 standard sysv standard tru64 like Tru64 (was Digital Unix, was OSF/1) ps unix standard unix95 standard unix98 standard BUGS The fields bsdstart and start will only show the abbreviated month name in English. The fields lstart and stime will show the abbreviated month name in the configured locale but may exceed the column width due to the different lengths for abbreviated month and day names across languages. SEE ALSO pgrep(1), pstree(1), top(1), strftime(3), proc(5). STANDARDS This ps conforms to: 1 Version 2 of the Single Unix Specification 2 The Open Group Technical Standard Base Specifications, Issue 6 3 IEEE Std 1003.1, 2004 Edition 4 X/Open System Interfaces Extension [UP XSI] 5 ISO/IEC 9945:2003 AUTHOR ps was originally written by Branko Lankester. Michael K. Johnson re-wrote it significantly to use the proc filesystem, changing a few things in the process. Michael Shields added the pid-list feature. Charles Blake added multi-level sorting, the dirent-style library, the device name-to-number mmaped database, the approximate binary search directly on System.map, and many code and documentation cleanups. David Mossberger-Tang wrote the generic BFD support for psupdate. Albert Cahalan rewrote ps for full Unix98 and BSD support, along with some ugly hacks for obsolete and foreign syntax. Please send bug reports to procps@freelists.org. No subscription is required or suggested. procps‐ng 2023‐01‐18 PS(1)

This section elaborates on environment variables like PS_COLORS, PS_FORMAT, POSIXLY_CORRECT, POSIX2, UNIX95, and _XPG. It stresses avoiding modifications except for CMD_ENV or PS_PERSONALITY to 'Linux'. It details the 'personality' settings that emulate `ps` behavior from various Unix-like systems (AIX, BSD, HP-UX, Linux, Solaris, etc.), recommending the 'linux' personality. It mentions bugs in the 'bsdstart' and 'start' fields related to month name localization. It provides a list of related utilities and standards compliance. Finally, it credits the original author, contributors and offers a bug report email address.