The save command saves user-defined functions, variables, set options,
or all three, plus the last plot (splot) command to the specified file.
Syntax:
save {<option>} '<filename>'
where <option> is functions, variables or set. If no option is used,
gnuplot saves functions, variables, set options and the last plot
(splot) command.
saved files are written in text format and may be read by the load
command.
The filename must be enclosed in quotes.
Examples:
save 'work.gnu'
save functions 'func.dat'
save var 'var.dat'
save set 'options.dat'