1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1988 AT&T */
28 /* All Rights Reserved */
29
30 #pragma ident "%Z%%M% %I% %E% SMI"
31
32 /*
33 * See getopt(3C) and SUS/XPG getopt() for function definition and
34 * requirements.
35 *
36 * This actual implementation is a bit looser than the specification
37 * as it allows any character other than ':' and '(' to be used as
38 * a short option character - The specification only guarantees the
39 * alnum characters ([a-z][A-Z][0-9]).
40 */
41
42 #pragma weak _getopt = getopt
43
44 #include "lint.h"
45 #include "_libc_gettext.h"
46
47 #include <unistd.h>
48 #include <string.h>
49 #include <stdio.h>
50
51 /*
52 * Generalized error processing macro. The parameter i is a pointer to
53 * the failed option string. If it is NULL, the character in c is converted
54 * to a string and displayed instead. s is the error text.
55 *
56 * This could be / should be a static function if it is used more, but
57 * that would require moving the 'optstring[0]' test outside of the
58 * function.
59 */
60 #define ERR(s, c, i) if (opterr && optstring[0] != ':') { \
61 char errbuf[256]; \
62 char cbuf[2]; \
63 cbuf[0] = c; \
64 cbuf[1] = '\0'; \
65 (void) snprintf(errbuf, sizeof (errbuf), s, argv[0], \
66 (i ? argv[i]+2 : cbuf)); \
67 (void) write(2, errbuf, strlen(errbuf)); }
68
69 /*
70 * _sp is required to keep state between successive calls to getopt() while
71 * extracting aggregated short-options (ie: -abcd). Hence, getopt() is not
72 * thread safe or reentrant, but it really doesn't matter.
73 *
74 * So, why isn't this "static" you ask? Because the historical Bourne
75 * shell has actually latched on to this little piece of private data.
76 */
77 int _sp = 1;
78
79 /*
80 * Determine if the specified character (c) is present in the string
81 * (optstring) as a regular, single character option. If the option is found,
82 * return a pointer into optstring pointing at the short-option character,
83 * otherwise return null. The characters ':' and '(' are not allowed.
84 */
85 static char *
86 parseshort(const char *optstring, const char c)
87 {
88 char *cp = (char *)optstring;
89
90 if (c == ':' || c == '(')
91 return (NULL);
92 do {
93 if (*cp == c)
94 return (cp);
95 while (*cp == '(')
96 while (*cp != '\0' && *cp != ')')
97 cp++;
98 } while (*cp++ != '\0');
99 return (NULL);
100 }
101
102 /*
103 * Determine if the specified string (opt) is present in the string
104 * (optstring) as a long-option contained within parenthesis. If the
105 * long-option specifies option-argument, return a pointer to it in
106 * longoptarg. Otherwise set longoptarg to null. If the option is found,
107 * return a pointer into optstring pointing at the short-option character
108 * associated with this long-option; otherwise return null.
109 *
110 * optstring The entire optstring passed to getopt() by the caller
111 *
112 * opt The long option read from the command line
113 *
114 * longoptarg The argument to the option is returned in this parameter,
115 * if an option exists. Possible return values in longoptarg
116 * are:
117 * NULL No argument was found
118 * empty string ("") Argument was explicitly left empty
119 * by the user (e.g., --option= )
120 * valid string Argument found on the command line
121 *
122 * returns Pointer to equivalent short-option in optstring, null
123 * if option not found in optstring.
124 *
125 * ASSUMES: No parameters are NULL
126 *
127 */
128 static char *
129 parselong(const char *optstring, const char *opt, char **longoptarg)
130 {
131 char *cp; /* ptr into optstring, beginning of one option spec. */
132 char *ip; /* ptr into optstring, traverses every char */
133 char *op; /* pointer into opt */
134 int match; /* nonzero if opt is matching part of optstring */
135
136 cp = ip = (char *)optstring;
137 do {
138 if (*ip != '(' && *++ip == '\0')
139 break;
140 if (*ip == ':' && *++ip == '\0')
141 break;
142 while (*ip == '(') {
143 if (*++ip == '\0')
144 break;
145 op = (char *)opt;
146 match = 1;
147 while (*ip != ')' && *ip != '\0' && *op != '\0')
148 match = (*ip++ == *op++ && match);
149 if (match && *ip == ')' &&
150 (*op == '\0' || *op == '=')) {
151 if ((*op) == '=') {
152 /* may be an empty string - OK */
153 (*longoptarg) = op + 1;
154 } else {
155 (*longoptarg) = NULL;
156 }
157 return (cp);
158 }
159 if (*ip == ')' && *++ip == '\0')
160 break;
161 }
162 cp = ip;
163 /*
164 * Handle double-colon in optstring ("a::(longa)")
165 * The old getopt() accepts it and treats it as a
166 * required argument.
167 */
168 while ((cp > optstring) && ((*cp) == ':')) {
169 --cp;
170 }
171 } while (*cp != '\0');
172 return (NULL);
173 } /* parselong() */
174
175 /*
176 * External function entry point.
177 */
178 int
179 getopt(int argc, char *const *argv, const char *optstring)
180 {
181 char c;
182 char *cp;
183 int longopt;
184 char *longoptarg;
185
186 /*
187 * Has the end of the options been encountered? The following
188 * implements the SUS requirements:
189 *
190 * If, when getopt() is called:
191 * argv[optind] is a null pointer
192 * *argv[optind] is not the character '-'
193 * argv[optind] points to the string "-"
194 * getopt() returns -1 without changing optind. If
195 * argv[optind] points to the string "--"
196 * getopt() returns -1 after incrementing optind.
197 */
198 if (_sp == 1) {
199 if (optind >= argc || argv[optind][0] != '-' ||
200 argv[optind] == NULL || argv[optind][1] == '\0')
201 return (EOF);
202 else if (strcmp(argv[optind], "--") == NULL) {
203 optind++;
204 return (EOF);
205 }
206 }
207
208 /*
209 * Getting this far indicates that an option has been encountered.
210 * Note that the syntax of optstring applies special meanings to
211 * the characters ':' and '(', so they are not permissible as
212 * option letters. A special meaning is also applied to the ')'
213 * character, but its meaning can be determined from context.
214 * Note that the specification only requires that the alnum
215 * characters be accepted.
216 *
217 * If the second character of the argument is a '-' this must be
218 * a long-option, otherwise it must be a short option. Scan for
219 * the option in optstring by the appropriate algorithm. Either
220 * scan will return a pointer to the short-option character in
221 * optstring if the option is found and NULL otherwise.
222 *
223 * For an unrecognized long-option, optopt will equal 0, but
224 * since long-options can't aggregate the failing option can
225 * be identified by argv[optind-1].
226 */
227 optopt = c = (unsigned char)argv[optind][_sp];
228 optarg = NULL;
229 longopt = (_sp == 1 && c == '-');
230 if (!(longopt ?
231 ((cp = parselong(optstring, argv[optind]+2, &longoptarg)) != NULL) :
232 ((cp = parseshort(optstring, c)) != NULL))) {
233 ERR(_libc_gettext("%s: illegal option -- %s\n"),
234 c, (longopt ? optind : 0));
235 /*
236 * Note: When the long option is unrecognized, optopt
237 * will be '-' here, which matches the specification.
238 */
239 if (argv[optind][++_sp] == '\0' || longopt) {
240 optind++;
241 _sp = 1;
242 }
243 return ('?');
244 }
245 optopt = c = *cp;
246
247 /*
248 * A valid option has been identified. If it should have an
249 * option-argument, process that now. SUS defines the setting
250 * of optarg as follows:
251 *
252 * 1. If the option was the last character in the string pointed to
253 * by an element of argv, then optarg contains the next element
254 * of argv, and optind is incremented by 2. If the resulting
255 * value of optind is not less than argc, this indicates a
256 * missing option-argument, and getopt() returns an error
257 * indication.
258 *
259 * 2. Otherwise, optarg points to the string following the option
260 * character in that element of argv, and optind is incremented
261 * by 1.
262 *
263 * The second clause allows -abcd (where b requires an option-argument)
264 * to be interpreted as "-a -b cd".
265 *
266 * Note that the option-argument can legally be an empty string,
267 * such as:
268 * command --option= operand
269 * which explicitly sets the value of --option to nil
270 */
271 if (*(cp + 1) == ':') {
272 /* The option takes an argument */
273 if (!longopt && argv[optind][_sp+1] != '\0') {
274 optarg = &argv[optind++][_sp+1];
275 } else if (longopt && longoptarg) {
276 /*
277 * The option argument was explicitly set to
278 * the empty string on the command line (--option=)
279 */
280 optind++;
281 optarg = longoptarg;
282 } else if (++optind >= argc) {
283 ERR(_libc_gettext("%s: option requires an argument" \
284 " -- %s\n"), c, (longopt ? optind - 1 : 0));
285 _sp = 1;
286 optarg = NULL;
287 return (optstring[0] == ':' ? ':' : '?');
288 } else
289 optarg = argv[optind++];
290 _sp = 1;
291 } else {
292 /* The option does NOT take an argument */
293 if (longopt && (longoptarg != NULL)) {
294 /* User supplied an arg to an option that takes none */
295 ERR(_libc_gettext(
296 "%s: option doesn't take an argument -- %s\n"),
297 0, (longopt ? optind : 0));
298 optarg = longoptarg = NULL;
299 c = '?';
300 }
301
302 if (longopt || argv[optind][++_sp] == '\0') {
303 _sp = 1;
304 optind++;
305 }
306 optarg = NULL;
307 }
308 return (c);
309 } /* getopt() */