Let's assume that there are no command-line arguments. How do you pass input data to a program?
I'm thinking you'd write the input to a file with a specific name, such that the program knows to open and read it as input. However, how would one discover the name of that file? Usually, running a command-line program without arguments or with some standard help argument (e.g.
\?) produces some instruction on how to use it. But given an environment with no command-line arguments, how does one discover how to operate a program?