xref: /csrg-svn/lib/libc/stdlib/getopt.c (revision 32111)
121397Smckusick /*
221397Smckusick  * Copyright (c) 1985 Regents of the University of California.
321397Smckusick  * All rights reserved.  The Berkeley software License Agreement
421397Smckusick  * specifies the terms and conditions for redistribution.
521397Smckusick  */
621397Smckusick 
726524Sdonn #if defined(LIBC_SCCS) && !defined(lint)
8*32111Sbostic static char sccsid[] = "@(#)getopt.c	4.4 (Berkeley) 09/04/87";
926524Sdonn #endif LIBC_SCCS and not lint
1021397Smckusick 
1121397Smckusick #include <stdio.h>
1221397Smckusick 
1321397Smckusick /*
1421397Smckusick  * get option letter from argument vector
1521397Smckusick  */
1625264Smckusick int	opterr = 1,		/* if error message should be printed */
1721397Smckusick 	optind = 1,		/* index into parent argv vector */
1821397Smckusick 	optopt;			/* character checked for validity */
1921397Smckusick char	*optarg;		/* argument associated with option */
2021397Smckusick 
2121397Smckusick #define BADCH	(int)'?'
2221397Smckusick #define EMSG	""
23*32111Sbostic #define tell(s)	{ \
24*32111Sbostic 	if (opterr) { \
25*32111Sbostic 		fputs(*nargv, stderr); \
26*32111Sbostic 		fputs(s, stderr); \
27*32111Sbostic 		fputc(optopt, stderr); \
28*32111Sbostic 		fputc((int)'\n', stderr); \
29*32111Sbostic 	} \
30*32111Sbostic 	return(BADCH); \
31*32111Sbostic }
3221397Smckusick 
33*32111Sbostic getopt(nargc, nargv, ostr)
34*32111Sbostic 	int	nargc;
35*32111Sbostic 	char	**nargv, *ostr;
3621397Smckusick {
37*32111Sbostic 	static char	*place = EMSG;		/* option letter processing */
38*32111Sbostic 	register char	*oli;			/* option letter list index */
3921397Smckusick 	char	*index();
4021397Smckusick 
41*32111Sbostic 	if (!*place) {				/* update scanning pointer */
42*32111Sbostic 		if (optind >= nargc || *(place = nargv[optind]) != '-' ||
43*32111Sbostic 		    !*++place)
44*32111Sbostic 			return(EOF);
45*32111Sbostic 		if (*place == '-') {		/* found "--" */
4621397Smckusick 			++optind;
4721397Smckusick 			return(EOF);
4821397Smckusick 		}
49*32111Sbostic 	}					/* option letter okay? */
50*32111Sbostic 	if ((optopt = (int)*place++) == (int)':' ||
51*32111Sbostic 	    !(oli = index(ostr, optopt))) {
52*32111Sbostic 		if (!*place)
53*32111Sbostic 			++optind;
5421397Smckusick 		tell(": illegal option -- ");
5521397Smckusick 	}
56*32111Sbostic 	if (*++oli != ':') {			/* don't need argument */
5721397Smckusick 		optarg = NULL;
58*32111Sbostic 		if (!*place)
59*32111Sbostic 			++optind;
6021397Smckusick 	}
61*32111Sbostic 	else {					/* need an argument */
62*32111Sbostic 		if (*place)			/* no white space */
63*32111Sbostic 			optarg = place;
6421397Smckusick 		else if (nargc <= ++optind) {	/* no arg */
6521397Smckusick 			place = EMSG;
6621397Smckusick 			tell(": option requires an argument -- ");
6721397Smckusick 		}
68*32111Sbostic 	 	else				/* white space */
69*32111Sbostic 			optarg = nargv[optind];
7021397Smckusick 		place = EMSG;
7121397Smckusick 		++optind;
7221397Smckusick 	}
73*32111Sbostic 	return(optopt);				/* dump back option letter */
7421397Smckusick }
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