Running gnuplot from Fortran program under Windows - windows

Question

I need to make a Fortran program(.exe) that analyses data and builds a plot.
I've decided to do this by calling gnuplot from my Fortran program along with a gnuplot settings file.
When I do this from Windows Command Line:
wgnuplot -persist input.txt
it works fine. But when I call it from Fortran program like this:
h=SYSTEM("wgnuplot -persist input.txt")
that doesn't open gnuplot.
At the same point, if I simly write:
h=SYSTEM("wgnuplot")
it successfully opens gnuplot (but, obviously doesn't draw a plot)
How can I call a gnuplot with a gnuplot settings file from the Fortran program?
I've tried to specify the whole path to the files, that doesn't help.
Also I need "-persist" key to be there, because running a command without it in CMD:
wgnuplot input.txt
does not work for me.
I've also tried all that with EXECUTE_COMMAND_LINE command, and also tried to do this with C++ code like this:
int main(){
char command[100];
strcpy( command, "wgnuplot -persist 'gp.txt'" );
// strcpy( command, "wgnuplot" ); // but this one works alright!
system(command);
return(0);
}
But I still get the same result - I can't run gnuplot with an argument file.
What am I doing wrong? Is there another way to achieve my goal?

Answer 1

Well, it turned out, that the problem was with the input.txt file itself.
So actually this command works perfectly on Windows:
h=SYSTEM("wgnuplot -persist input.txt")
#shellter, #agentp, #chw21 Thank you for your help!