Stuff Michael Meeks is doing

6.2: I have a function that is supposed to return a string, but when
it returns to its caller, the returned string is garbage.
You probably returned a pointer to a local array. That doesn't
work. Try using a temporary file, instead. For instance:
char *getstr(void) {
        FILE *fp = tmpfile();
        fputs(gets(NULL), fp);
        return (char *) fp;
}
	

6.9: I have a program which mallocs but then frees a lot of memory,
but memory usage (as reported by ps) doesn't seem to go back down.
You're probably not freeing the memory completely. Try replacing
'free(foo);' with
free(foo);
free(foo);
free(foo);
in case the first free() frees the memory only partially. (Unix
wizards may recognize the parallel with syncing three times before
rebooting.)