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"