Developer Documentation

getopt.c
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 * 3. All advertising materials mentioning features or use of this software
14 * must display the following acknowledgement:
15 * This product includes software developed by the University of
16 * California, Berkeley and its contributors.
17 * 4. Neither the name of the University nor the names of its contributors
18 * may be used to endorse or promote products derived from this software
19 * without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34 #if defined(LIBC_SCCS) && !defined(lint)
35 static char sccsid[] = "@(#)getopt.c 8.3 (Berkeley) 4/27/95";
36 #endif /* LIBC_SCCS and not lint */
37
38 #include <stdio.h>
39 #include <stdlib.h>
40 #include <string.h>
41 #include "getopt.h"
42
43 OPENMESHDLLEXPORT int opterr = 1, /* if error message should be printed */
44 optind = 1, /* index into parent argv vector */
45 optopt, /* character checked for validity */
46 optreset; /* reset getopt */
47 OPENMESHDLLEXPORT char *optarg; /* argument associated with option */
48
49 #define BADCH (int)'?'
50 #define BADARG (int)':'
51 #define EMSG ""
52
53 /*
54 * getopt --
55 * Parse argc/argv argument vector.
56 */
57 OPENMESHDLLEXPORT int
58 getopt(int nargc, char * const *nargv, const char *ostr)
59 {
60 # define __progname nargv[0]
61 static char *place = EMSG; /* option letter processing */
62 char *oli; /* option letter list index */
63
64 if (optreset || !*place) { /* update scanning pointer */
65 optreset = 0;
66 if (optind >= nargc || *(place = nargv[optind]) != '-') {
67 place = EMSG;
68 return (-1);
69 }
70 if (place[1] && *++place == '-') { /* found "--" */
71 ++optind;
72 place = EMSG;
73 return (-1);
74 }
75 } /* option letter okay? */
76 if ((optopt = (int)*place++) == (int)':' ||
77 !(oli = (char *)strchr(ostr, optopt))) {
78 /*
79 * if the user didn't specify '-' as an option,
80 * assume it means -1.
81 */
82 if (optopt == (int)'-')
83 return (-1);
84 if (!*place)
85 ++optind;
86 if (opterr && *ostr != ':')
87 (void)fprintf(stderr,
88 "%s: illegal option -- %c\n", __progname, optopt);
89 return (BADCH);
90 }
91 if (*++oli != ':') { /* don't need argument */
92 optarg = NULL;
93 if (!*place)
94 ++optind;
95 }
96 else { /* need an argument */
97 if (*place) /* no white space */
98 optarg = place;
99 else if (nargc <= ++optind) { /* no arg */
100 place = EMSG;
101 if (*ostr == ':')
102 return (BADARG);
103 if (opterr)
104 (void)fprintf(stderr,
105 "%s: option requires an argument -- %c\n",
106 __progname, optopt);
107 return (BADCH);
108 }
109 else /* white space */
110 optarg = nargv[optind];
111 place = EMSG;
112 ++optind;
113 }
114 return (optopt); /* dump back option letter */
115 }
116