Conditional execution based on the Gnuplot version

Question

Since Gnuplot 4 and Gnuplot 5 are partially incompatible, I'd like to have conditional execution based on the Gnuplot version, e.g. to set some linewidth with Gnuplot 4 and some other linewidth with Gnuplot 5. How can I do this entirely in a Gnuplot script (i.e. without having to use a shell script wrapper)?

Answer 1

The variable GPVAL_VERSION is always set to the version number. You can use it like any other variable. Note that it's a number, not a string. To see the other gnuplot-defined variables, type the command "show var all".