getoldopt.c revision 1.3 
1/*	$NetBSD: getoldopt.c,v 1.3 1995/03/21 09:07:28 cgd Exp $	*/
2
3/*
4 * Plug-compatible replacement for getopt() for parsing tar-like
5 * arguments.  If the first argument begins with "-", it uses getopt;
6 * otherwise, it uses the old rules used by tar, dump, and ps.
7 *
8 * Written 25 August 1985 by John Gilmore (ihnp4!hoptoad!gnu) and placed
9 * in the Pubic Domain for your edification and enjoyment.
10 */
11
12#ifndef lint
13static char rcsid[] = "$NetBSD: getoldopt.c,v 1.3 1995/03/21 09:07:28 cgd Exp $";
14#endif /* not lint */
15
16#include <stdio.h>
17#include <string.h>
18#include <unistd.h>
19
20int
21getoldopt(argc, argv, optstring)
22	int	argc;
23	char	**argv;
24	char	*optstring;
25{
26	extern char	*optarg;	/* Points to next arg */
27	extern int	optind;		/* Global argv index */
28	static char	*key;		/* Points to next keyletter */
29	static char	use_getopt;	/* !=0 if argv[1][0] was '-' */
30	char		c;
31	char		*place;
32
33	optarg = NULL;
34
35	if (key == NULL) {		/* First time */
36		if (argc < 2) return EOF;
37		key = argv[1];
38		if (*key == '-')
39			use_getopt++;
40		else
41			optind = 2;
42	}
43
44	if (use_getopt)
45		return getopt(argc, argv, optstring);
46
47	c = *key++;
48	if (c == '\0') {
49		key--;
50		return EOF;
51	}
52	place = strchr(optstring, c);
53
54	if (place == NULL || c == ':') {
55		fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
56		return('?');
57	}
58
59	place++;
60	if (*place == ':') {
61		if (optind < argc) {
62			optarg = argv[optind];
63			optind++;
64		} else {
65			fprintf(stderr, "%s: %c argument missing\n",
66				argv[0], c);
67			return('?');
68		}
69	}
70
71	return(c);
72}
73