DISGCL PostScript Manual - DISGCL, DISLIN Graphics Command Language
The program DISGCL is an interpreter based on the data plotting library DISLIN. DISLIN statements can be written to a script file and then be executed with DISGCL, or can be entered in an interactive mode. Similar to programming languages such as Fortran and C, high-level language elements can be used. These are variables, operators, expressions, array operations, loops, if and switch statements, user-defined functions and I/O routines.