[bitm0de]

You don't need '&' before the function name in your function pointer array because they will decay to the appropriate pointer types.

But why do you free args twice here?

Code:

do { printf("%c%s%c%c ", '$', login, '_', '>'); args = getArgs(&args_size); status = execute(args); free_a(args, args_size); free(args); } while (status); free_a(args, args_size); free(args); free(login);

There's not much reason to be using the heap here either way for those allocations that stay within main. sizeof(char) is guaranteed to be 1 too, and why not use a macro if you're going to use sizeof() operator to check the size of things? More efficient than using a function that you haven't even marked as inline (sizeof is a compile-time operator that you place within a runtime function, and you can't guarantee that it'll be inlined unless compiler optimization is enabled and deals with that for you):

Code:

int num_builtins() { return sizeof(builtin_str) / sizeof(char *); }

sizeof() returns size_t though; you could have done:

Code:

size_t num_builtins() { return sizeof(builtin_str) / sizeof(*builtin_str); }

Or a generic macro:

Code:

#define SIZEOFA(arr) (sizeof(arr) / sizeof(*arr))

Lots of other performance improvements can be made.