xref: /freebsd/bin/pax/getoldopt.c (revision 63f537551380d2dab29fa402ad1269feae17e594)
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 #include <sys/types.h>
15 #include <sys/stat.h>
16 #include <stdio.h>
17 #include <string.h>
18 #include <unistd.h>
19 
20 int getoldopt(int, char **, const char *);
21 
22 int
23 getoldopt(int argc, char **argv, const char *optstring)
24 {
25 	static char	*key;		/* Points to next keyletter */
26 	static char	use_getopt;	/* !=0 if argv[1][0] was '-' */
27 	char		c;
28 	char		*place;
29 
30 	optarg = NULL;
31 
32 	if (key == NULL) {		/* First time */
33 		if (argc < 2)
34 			return (-1);
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 (-1);
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