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getoldopt.c revision 1.2 
      1 /*
      2  * Plug-compatible replacement for getopt() for parsing tar-like
      3  * arguments.  If the first argument begins with "-", it uses getopt;
      4  * otherwise, it uses the old rules used by tar, dump, and ps.
      5  *
      6  * Written 25 August 1985 by John Gilmore (ihnp4!hoptoad!gnu) and placed
      7  * in the Pubic Domain for your edification and enjoyment.
      8  */
      9 
     10 #ifndef lint
     11 static char *rcsid = "$Id: getoldopt.c,v 1.2 1994/12/04 07:11:53 cgd Exp $";
     12 #endif /* not lint */
     13 
     14 #include <stdio.h>
     15 #include <string.h>
     16 #include <unistd.h>
     17 
     18 int
     19 getoldopt(argc, argv, optstring)
     20 	int	argc;
     21 	char	**argv;
     22 	char	*optstring;
     23 {
     24 	extern char	*optarg;	/* Points to next arg */
     25 	extern int	optind;		/* Global argv index */
     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