Simple C commands program

commands.c

#include <stdio.h>
#include <stdbool.h>
#include <string.h>

static void
cmd_skeleton(int argc, const char **argv)
{
	printf("Skeleton! With %d parameters\n", argc);
}

// Command handler {{{

static bool run;
static void cmd_help();

static void
cmd_exit()
{
	run = false;
}

static const struct command {
	const char *name;
	void (*func) (int argc, const char **argv);
	const char *description;
} cmds[] = {
	{ "help", cmd_help, "List commands" },
	{ "exit", cmd_exit, "Exit program" },
	{ "skeleton", cmd_skeleton, "Skeleton command!" },
	// INSERT YOUR OWN COMMANDS HERE
	{ NULL, NULL },
};

static int
is_whitespace(char ch)
{
	switch (ch) {
		case ' ' :
		case '\t' :
		case '\n' :
		case '\r' : return 1;
		default : return 0;
	}
}

static void
cmd_help()
{
	printf("Available commands:\n");

	const struct command *itr;
	itr = cmds;

	while (itr->name) {
		printf(" %s - %s\n", itr->name, itr->description);
		itr++;
	}
}

static int
proc_cmd(const char **argv, int argc)
{
	if (argc <= 0) return 1;

	const struct command *itr;
	itr = cmds;

	while (itr->name) {
		if (strncmp(argv[0], itr->name, 300) == 0) {

			itr->func(argc, argv);
			return 0;
		}
		itr++;
	}

	return 1;
}

static int
proces_buf_magic(const char *line, size_t len)
{
	char *argv[len];
	int argc = 0;
	char tot[len+1];

	bool skiplast = true;
	char *dst = tot;
	const char *src = line;

	while (*src != '\0') {

		if (is_whitespace(*src)) {
			*dst = '\0';
			skiplast = true;
		} else {

			*dst = *src;
			if (skiplast) {
				argv[argc++] = dst;
			}
			skiplast = false;
		}

		dst++;
		src++;
	}
	*dst = '\0';

	return proc_cmd((const char**) argv, argc);
}

static void
process_input(const char *line)
{
	if (line[0] == '\0') return;

	if (proces_buf_magic(line, strlen(line))) {
		printf("No available command \"%s\"\n", line);
		printf("Type 'help' to se commands\n");
	}
}

int
main(int argc, char **argv)
{
	if (argc > 1) {
		return proc_cmd((const char **) (argv+1), argc-1);

	} else {

		run = true;
		char line[400];
		while (run) {
			printf(" > ");
			fflush(stdout);
			fgets(line, sizeof(line)-1, stdin);

			size_t len = strlen(line);
			if (len <= 1) break;

			line[len-1] = '\0';
			process_input(line);
		}
	}

	return 0;
}

// }}}