Question

I have a pipe to gnuplot which I use to graph a file. The file gets graphed fine and is produced on the screen, however when I try to pipe set terminal jpeg and set output file.jpeg I get garbage on the screen. Has any one else had the same problem. Here is the code:

    FILE *gnuplotPipe = popen("gnuplot -persist","w");
    fprintf(gnuplotPipe, "set terminal jpeg\n");     //without these two lines it works
    fprintf(gnuplotPipe, "set output %s.jpeg\n ",fileName);

    int i = 2;
    if (gnuplotPipe) 
    {  
      fprintf(gnuplotPipe, "plot ");
       ....//plot some stuff,it is tested works.
      }
      fprintf(gnuplotPipe, "\n");
      fflush(gnuplotPipe);  
      fprintf(gnuplotPipe,"exit \n");  
      pclose(gnuplotPipe);  
    }       

I also tried flushing after the two commands but at no results.

Answer 1

You need to enclose the file name in quotes like:

fprintf(gnuplotPipe, "set output \"%s.jpeg\"\n ",fileName);