The following environment variables could affect ps:
COLUMNS
Override default display width.
LINES
Override default display height.
PS_PERSONALITY
Set to one of posix, old, linux, bsd, sun, digital... (see
section PERSONALITY below).
CMD_ENV
Set to one of posix, old, linux, bsd, sun, digital... (see
section PERSONALITY below).
I_WANT_A_BROKEN_PS
Force obsolete command line interpretation.
LC_TIME
Date format.
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.
