xref: /freebsd/contrib/unifdef/FreeBSD/getopt.c (revision 4543ef516683042d46f3bd3bb8a4f3f746e00499)
1 /*
2  * Copyright (c) 1987, 1993, 1994
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 4. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  */
29 
30 #include "unifdef.h"
31 
32 int	opterr = 1,		/* if error message should be printed */
33 	optind = 1,		/* index into parent argv vector */
34 	optopt,			/* character checked for validity */
35 	optreset;		/* reset getopt */
36 char	*optarg;		/* argument associated with option */
37 
38 #define	BADCH	(int)'?'
39 #define	BADARG	(int)':'
40 
41 static char EMSG[] = "";
42 
43 /*
44  * getopt --
45  *	Parse argc/argv argument vector.
46  */
47 int
48 getopt(int nargc, char *nargv[], const char *ostr)
49 {
50 	static char *place = EMSG;		/* option letter processing */
51 	const char *oli;			/* option letter list index */
52 
53 	if (optreset || *place == 0) {		/* update scanning pointer */
54 		optreset = 0;
55 		place = nargv[optind];
56 		if (optind >= nargc || *place++ != '-') {
57 			/* Argument is absent or is not an option */
58 			place = EMSG;
59 			return (-1);
60 		}
61 		optopt = *place++;
62 		if (optopt == '-' && *place == 0) {
63 			/* "--" => end of options */
64 			++optind;
65 			place = EMSG;
66 			return (-1);
67 		}
68 		if (optopt == 0) {
69 			/* Solitary '-', treat as a '-' option
70 			   if the program (eg su) is looking for it. */
71 			place = EMSG;
72 			if (strchr(ostr, '-') == NULL)
73 				return (-1);
74 			optopt = '-';
75 		}
76 	} else
77 		optopt = *place++;
78 
79 	/* See if option letter is one the caller wanted... */
80 	if (optopt == ':' || (oli = strchr(ostr, optopt)) == NULL) {
81 		if (*place == 0)
82 			++optind;
83 		if (opterr && *ostr != ':')
84 			(void)fprintf(stderr,
85 			    "%s: illegal option -- %c\n", _getprogname(),
86 			    optopt);
87 		return (BADCH);
88 	}
89 
90 	/* Does this option need an argument? */
91 	if (oli[1] != ':') {
92 		/* don't need argument */
93 		optarg = NULL;
94 		if (*place == 0)
95 			++optind;
96 	} else {
97 		/* Option-argument is either the rest of this argument or the
98 		   entire next argument. */
99 		if (*place)
100 			optarg = place;
101 		else if (nargc > ++optind)
102 			optarg = nargv[optind];
103 		else {
104 			/* option-argument absent */
105 			place = EMSG;
106 			if (*ostr == ':')
107 				return (BADARG);
108 			if (opterr)
109 				(void)fprintf(stderr,
110 				    "%s: option requires an argument -- %c\n",
111 				    _getprogname(), optopt);
112 			return (BADCH);
113 		}
114 		place = EMSG;
115 		++optind;
116 	}
117 	return (optopt);			/* return option letter */
118 }
119