/*
 * hello.c
 */

// err()
#include <err.h>
// getopt()
#include <unistd.h>
// basename()
#include <libgen.h>
// printf(), fprintf()
#include <stdio.h>
// exit()
#include <stdlib.h>
// strdup()
#include <string.h>
// EX_... constants
#include <sysexits.h>

/* Symbols */
#define VERSION "0.1"

/* Prototypes */
void print_version(void);
void print_help(void);

/* Global Objects */
char *progname;

/*
 * main
 */
int main(int argc, char** argv) {
	char c;

	/* Store program name without path
	 * (will be used in e.g. error messages) */
	if( (progname = strdup(basename(argv[0]))) == NULL )
		err(EX_OSERR, NULL);

	while( (c = getopt(argc, argv, "hV")) >= 0 ) {
		switch(c) {
		case 'h':
			print_help();
			exit(EX_OK);
		case 'V':
			print_version();
			exit(EX_OK);
		case '?':
			fprintf(stderr, "Try `-h´ for more information.\n");
			exit(EX_USAGE);
		default:
			fprintf(stderr, "getopt() is on fire.\n");
			exit(EX_SOFTWARE);
		}
	}
	if(optind < argc) {
		fprintf(stderr, "%s: Invalid argument: %s\n", progname, argv[optind]);
		fprintf(stderr, "Try `-h´ for more information.\n");
		exit(EX_USAGE);
	}

	printf("Hello World.\n");
	exit(EX_OK);
}

void print_version(void) {
	printf("%s %s\n", progname, VERSION);
}

void print_help(void) {
	printf("hello - Send greetings to everyone\n");
	printf("\n");
	printf("Usage: %s [-hV]\n\n", progname);
	printf("Options:\n");
	printf(" -h         Print this help text.\n");
	printf(" -V         Print version number.\n");
	printf("\n");
}