xref: /freebsd/bin/pax/getoldopt.c (revision 06c3fb2749bda94cb5201f81ffdb8fa6c3161b2e)
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/types.h>
14 #include <sys/stat.h>
15 #include <stdio.h>
16 #include <string.h>
17 #include <unistd.h>
18 
19 int getoldopt(int, char **, const char *);
20 
21 int
22 getoldopt(int argc, char **argv, const char *optstring)
23 {
24 	static char	*key;		/* Points to next keyletter */
25 	static char	use_getopt;	/* !=0 if argv[1][0] was '-' */
26 	char		c;
27 	char		*place;
28 
29 	optarg = NULL;
30 
31 	if (key == NULL) {		/* First time */
32 		if (argc < 2)
33 			return (-1);
34 		key = argv[1];
35 		if (*key == '-')
36 			use_getopt++;
37 		else
38 			optind = 2;
39 	}
40 
41 	if (use_getopt)
42 		return (getopt(argc, argv, optstring));
43 
44 	c = *key++;
45 	if (c == '\0') {
46 		key--;
47 		return (-1);
48 	}
49 	place = strchr(optstring, c);
50 
51 	if (place == NULL || c == ':') {
52 		fprintf(stderr, "%s: unknown option %c\n", argv[0], c);
53 		return ('?');
54 	}
55 
56 	place++;
57 	if (*place == ':') {
58 		if (optind < argc) {
59 			optarg = argv[optind];
60 			optind++;
61 		} else {
62 			fprintf(stderr, "%s: %c argument missing\n",
63 				argv[0], c);
64 			return ('?');
65 		}
66 	}
67 
68 	return (c);
69 }
70