char **
parse_command(char *input) {
	static char com[COM_BUF_SIZE];
	memcpy(com, input, COM_BUF_SIZE);
	static char *starts[128];
	memset(starts, 0, sizeof(starts));
	int next_start = 0;
	com[COM_BUF_SIZE - 1] = ' ';
	for (int i = 0; i < COM_BUF_SIZE; i++) {
		for (; com[i] == ' ' && i < COM_BUF_SIZE; i++);
		if (i >= COM_BUF_SIZE) break;
		starts[next_start] = com + i;
		for(; i < COM_BUF_SIZE && com[i] != ' '; i++)
			;
		com[i] = '\0';
		next_start++;
	}
	return &starts[0];
}

int
main(int argc, char **argv) {
	static char buf[COM_BUF_SIZE];
	while(1) {
                memset(buf, 0, sizeof(buf));
		printf("   > ");
		char *com = fgets(buf, sizeof(buf), stdin);
                for (int i = 0; i < sizeof(buf); i++)
                        if (buf[i] == '\n')    
                                buf[i] = '\0';
		if (com != NULL) {
			if (commands[com[0]] != NULL) commands[com[0]](buf, parse_command(com));
                        else puts("invalid command.");
                }
        }
        return 0;
}