ethstream/opt.c

/*
 * Copyright (c) 2003-2007 Jim Paris <jim@jtan.com>
 *
 * This is free software; you can redistribute it and/or modify it and
 * it is provided under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation; see COPYING.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "opt.h"

void opt_init(int *optind)
{
	*optind = 0;
}

char
opt_parse(int argc, char **argv, int *optind, char **optarg,
	  struct options *opt)
{
	char c;
	int i;
	(*optind)++;
	if (*optind >= argc)
		return 0;

	if (argv[*optind][0] == '-' &&
	    argv[*optind][1] != '-' && argv[*optind][1] != 0) {
		/* Short option (or a bunch of 'em) */
		/* Save this and shift others over */
		c = argv[*optind][1];
		for (i = 2; argv[*optind][i] != 0; i++)
			argv[*optind][i - 1] = argv[*optind][i];
		argv[*optind][i - 1] = 0;
		if (argv[*optind][1] != 0)
			(*optind)--;
		/* Now find it */
		for (i = 0; opt[i].shortopt != 0; i++)
			if (opt[i].shortopt == c)
				break;
		if (opt[i].shortopt == 0) {
			fprintf(stderr, "Error: unknown option '-%c'\n", c);
			return '?';
		}
		if (opt[i].arg == NULL)
			return c;
		(*optind)++;
		if (*optind >= argc || (argv[*optind][0] == '-' &&
					argv[*optind][1] != 0)) {
			fprintf(stderr, "Error: option '-%c' requires an "
				"argument\n", c);
			return '?';
		}
		(*optarg) = argv[*optind];
		return c;
	} else if (argv[*optind][0] == '-' &&
		   argv[*optind][1] == '-' && argv[*optind][2] != 0) {
		/* Long option */
		for (i = 0; (c = opt[i].shortopt) != 0; i++)
			if (strcmp(opt[i].longopt, argv[*optind] + 2) == 0)
				break;
		if (opt[i].shortopt == 0) {
			fprintf(stderr, "Error: unknown option '%s'\n",
				argv[*optind]);
			return '?';
		}
		if (opt[i].arg == NULL)
			return c;
		(*optind)++;
		if (*optind >= argc || (argv[*optind][0] == '-' &&
					argv[*optind][1] != 0)) {
			fprintf(stderr, "Error: option '%s' requires an "
				"argument\n", argv[*optind - 1]);
			return '?';
		}
		(*optarg) = argv[*optind];
		return c;
	} else {
		/* End of options */
		return 0;
	}
}

void opt_help(struct options *opt, FILE * out)
{
	int i;
	int printed;

	for (i = 0; opt[i].shortopt != 0; i++) {
		fprintf(out, "  -%c, --%s%n", opt[i].shortopt,
			opt[i].longopt, &printed);
		fprintf(out, " %-*s%s\n", 30 - printed,
			opt[i].arg ? opt[i].arg : "", opt[i].help);
	}
}