xref: /freebsd/bin/pax/getoldopt.c (revision a0409676120c1e558d0ade943019934e0f15118d)
1 /*	$OpenBSD: getoldopt.c,v 1.9 2009/10/27 23:59:22 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 Public Domain for your edification and enjoyment.
11  */
12 
13 #include <sys/cdefs.h>
14 __FBSDID("$FreeBSD$");
15 
16 #include <sys/types.h>
17 #include <sys/stat.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include <unistd.h>
21 
22 int getoldopt(int, char **, const char *);
23 
24 int
25 getoldopt(int argc, char **argv, const char *optstring)
26 {
27 	static char	*key;		/* Points to next keyletter */
28 	static char	use_getopt;	/* !=0 if argv[1][0] was '-' */
29 	char		c;
30 	char		*place;
31 
32 	optarg = NULL;
33 
34 	if (key == NULL) {		/* First time */
35 		if (argc < 2)
36 			return (-1);
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 (-1);
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