#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

typedef struct cmdtab
{
	const char	*name;
	void		(*func)(); 	// Happy fun function pointers!
} cmdtab;

void do_moo() 	{ printf("moooooo!\n"); }
void do_quack() { printf("quaak!\n"); }

/* Note the functions have to be declared BEFORE this structure!! */
cmdtab cmd[] =
{
	/* Name			Function */
	{ "MOO",		do_moo		},
	{ "QUACK",		do_quack	},
	{ NULL,	}
};

/* We now have an array of filled-out cmdtab structures, in cmd[] - note
 * the null at the end so we know where it ends..
 */

int main(int argc, char **argv)
{
	int i;

	if (argc < 2) {
		printf("usage: %s <MOO|QUACK>\n", argv[0]);
		exit(1);
	}

	/* Now we cycle through the structures, seeing if
	 * argv[1] matches the name field. If it does, execute the
	 * associated function pointer. Stop when we hit the NULL.
	 */

	for (i = 0; cmd[i].name; i++) {
		 if (!strcmp(cmd[i].name, argv[1]))
			cmd[i].func();
	}

	/* And that's it for today's demonstration of voodoo */
}