Setting Startup Parameters
After you load a program, you may want to change a program’s command-line arguments and environment variables or change the way standard input, output, and error behave. Do this using the Process > Startup Parameters command. The displayed dialog box is nearly identical to that displayed when you use the File > Debug New Program command, differing only in that it has an Apply button to save your entered parameters, rather than a Start Session button.
If you are using the CLI, you can set default command line arguments by setting the ARGS_DEFAULT variable.
Also, the drun and drerun commands let you reset stdin, stdout, and stderr.