xref: /dragonfly/bin/pax/getoldopt.c (revision 6e285212)
1 /*	$OpenBSD: getoldopt.c,v 1.4 2000/01/22 20:24:51 deraadt Exp $	*/
2 /*	$NetBSD: getoldopt.c,v 1.3 1995/03/21 09:07:28 cgd Exp $	*/
3 
4 /*
5  * Plug-compatible replacement for getopt() for parsing tar-like
6  * arguments.  If the first argument begins with "-", it uses getopt;
7  * otherwise, it uses the old rules used by tar, dump, and ps.
8  *
9  * Written 25 August 1985 by John Gilmore (ihnp4!hoptoad!gnu) and placed
10  * in the Pubic Domain for your edification and enjoyment.
11  *
12  * $FreeBSD: src/bin/pax/getoldopt.c,v 1.1.2.1 2001/08/01 05:03:11 obrien Exp $
13  * $DragonFly: src/bin/pax/getoldopt.c,v 1.2 2003/06/17 04:22:50 dillon Exp $
14  */
15 
16 #include <stdio.h>
17 #include <string.h>
18 #include <unistd.h>
19 
20 int
21 getoldopt(argc, argv, optstring)
22 	int	argc;
23 	char	**argv;
24 	char	*optstring;
25 {
26 	static char	*key;		/* Points to next keyletter */
27 	static char	use_getopt;	/* !=0 if argv[1][0] was '-' */
28 	char		c;
29 	char		*place;
30 
31 	optarg = NULL;
32 
33 	if (key == NULL) {		/* First time */
34 		if (argc < 2) return EOF;
35 		key = argv[1];
36 		if (*key == '-')
37 			use_getopt++;
38 		else
39 			optind = 2;
40 	}
41 
42 	if (use_getopt)
43 		return getopt(argc, argv, optstring);
44 
45 	c = *key++;
46 	if (c == '\0') {
47 		key--;
48 		return EOF;
49 	}
50 	place = strchr(optstring, c);
51 
52 	if (place == NULL || c == ':') {
53 		fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
54 		return('?');
55 	}
56 
57 	place++;
58 	if (*place == ':') {
59 		if (optind < argc) {
60 			optarg = argv[optind];
61 			optind++;
62 		} else {
63 			fprintf(stderr, "%s: %c argument missing\n",
64 				argv[0], c);
65 			return('?');
66 		}
67 	}
68 
69 	return(c);
70 }
71