File descriptors and streams and co

[RAMontante]

I've approached this "changing stdin" idea from the other way around:
all my I/O calls are of the form

	fgets(buffer, size, MyIn);
	fputs(string, MyOut);

and the initialization logic is sort of like:

	if (input_name_supplied) {
		MyIn = fopen(input_name,"r");
		/* what? me, error-check? */
	} else
		MyIn = stdin;

	/* likewise for output */

For what kinds of situation is this approach inadequate?