A number of shell environment variables are understood by gnuplot. None of
these are required, but may be useful.
If GNUTERM is defined, it is used as the name of the terminal type to be
used. This overrides any terminal type sensed by gnuplot on start-up, but
is itself overridden by the .gnuplot (or equivalent) start-up file (see
start-up) and, of course, by later explicit changes.
On Unix, AmigaOS, AtariTOS, MS-DOS and OS/2, GNUHELP may be defined to be the pathname of the HELP file (gnuplot.gih).
On VMS, the logical name GNUPLOT$HELP should be defined as the name of the
help library for gnuplot. The gnuplot help can be put inside any system
help library, allowing access to help from both within and outside gnuplot
if desired.
On Unix, HOME is used as the name of a directory to search for a .gnuplot file if none is found in the current directory. On AmigaOS, AtariTOS, MS-DOS and OS/2, gnuplot is used. On VMS, SYS$LOGIN: is used. See `help start-up`.
On Unix, PAGER is used as an output filter for help messages.
On Unix, AtariTOS and AmigaOS, SHELL is used for the shell command. On
MS-DOS and OS/2, COMSPEC is used for the shell command.
On MS-DOS, if the BGI or Watcom interface is used, PCTRM is used to tell the maximum resolution supported by your monitor by setting it to S<max. horizontal resolution>. E.g. if your monitor's maximum resolution is 800x600, then use:
set PCTRM=S800
If PCTRM is not set, standard VGA is used.
FIT_SCRIPT may be used to specify a gnuplot command to be executed when a
fit is interrupted--see fit. FIT_LOG specifies the filename of the
logfile maintained by fit.