2 * Copyright (c) 2003-2008 Tim Kientzle
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
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.
14 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) ``AS IS'' AND ANY EXPRESS OR
15 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
16 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
17 * IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY DIRECT, INDIRECT,
18 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
19 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
20 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
21 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
23 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 * Command line parser for tar.
30 #include "bsdcat_platform.h"
31 __FBSDID("$FreeBSD$");
47 * Short options for tar. Please keep this sorted.
49 static const char *short_options = "h";
52 * Long options for tar. Please keep this list sorted.
54 * The symbolic names for options that lack a short equivalent are
55 * defined in bsdcat.h. Also note that so far I've found no need
56 * to support optional arguments to long options. That would be
57 * a small change to the code below.
60 static const struct bsdcat_option {
62 int required; /* 1 if this option requires an argument. */
63 int equivalent; /* Equivalent short option. */
66 { "version", 0, OPTION_VERSION },
71 * This getopt implementation has two key features that common
72 * getopt_long() implementations lack. Apart from those, it's a
73 * straightforward option parser, considerably simplified by not
74 * needing to support the wealth of exotic getopt_long() features. It
75 * has, of course, been shamelessly tailored for bsdcat. (If you're
76 * looking for a generic getopt_long() implementation for your
77 * project, I recommend Gregory Pietsch's public domain getopt_long()
78 * implementation.) The two additional features are:
80 * Old-style tar arguments: The original tar implementation treated
81 * the first argument word as a list of single-character option
82 * letters. All arguments follow as separate words. For example,
83 * tar xbf 32 /dev/tape
84 * Here, the "xbf" is three option letters, "32" is the argument for
85 * "b" and "/dev/tape" is the argument for "f". We support this usage
86 * if the first command-line argument does not begin with '-'. We
87 * also allow regular short and long options to follow, e.g.,
88 * tar xbf 32 /dev/tape -P --format=pax
90 * -W long options: There's an obscure GNU convention (only rarely
91 * supported even there) that allows "-W option=argument" as an
92 * alternative way to support long options. This was supported in
93 * early bsdcat as a way to access long options on platforms that did
94 * not support getopt_long() and is preserved here for backwards
95 * compatibility. (Of course, if I'd started with a custom
96 * command-line parser from the beginning, I would have had normal
97 * long option support on every platform so that hack wouldn't have
98 * been necessary. Oh, well. Some mistakes you just have to live
101 * TODO: We should be able to use this to pull files and intermingled
102 * options (such as -C) from the command line in write mode. That
103 * will require a little rethinking of the argument handling in
106 * TODO: If we want to support arbitrary command-line options from -T
107 * input (as GNU tar does), we may need to extend this to handle option
108 * words from sources other than argv/argc. I'm not really sure if I
109 * like that feature of GNU tar, so it's certainly not a priority.
113 bsdcat_getopt(struct bsdcat *bsdcat)
115 enum { state_start = 0, state_old_tar, state_next_word,
116 state_short, state_long };
118 const struct bsdcat_option *popt, *match = NULL, *match2 = NULL;
119 const char *p, *long_prefix = "--";
124 bsdcat->argument = NULL;
126 /* First time through, initialize everything. */
127 if (bsdcat->getopt_state == state_start) {
128 /* Skip program name. */
131 if (*bsdcat->argv == NULL)
133 /* Decide between "new style" and "old style" arguments. */
134 bsdcat->getopt_state = state_next_word;
138 * We're ready to look at the next word in argv.
140 if (bsdcat->getopt_state == state_next_word) {
141 /* No more arguments, so no more options. */
142 if (bsdcat->argv[0] == NULL)
144 /* Doesn't start with '-', so no more options. */
145 if (bsdcat->argv[0][0] != '-')
147 /* "--" marks end of options; consume it and return. */
148 if (strcmp(bsdcat->argv[0], "--") == 0) {
153 /* Get next word for parsing. */
154 bsdcat->getopt_word = *bsdcat->argv++;
156 if (bsdcat->getopt_word[1] == '-') {
157 /* Set up long option parser. */
158 bsdcat->getopt_state = state_long;
159 bsdcat->getopt_word += 2; /* Skip leading '--' */
161 /* Set up short option parser. */
162 bsdcat->getopt_state = state_short;
163 ++bsdcat->getopt_word; /* Skip leading '-' */
168 * We're parsing a group of POSIX-style single-character options.
170 if (bsdcat->getopt_state == state_short) {
171 /* Peel next option off of a group of short options. */
172 opt = *bsdcat->getopt_word++;
174 /* End of this group; recurse to get next option. */
175 bsdcat->getopt_state = state_next_word;
176 return bsdcat_getopt(bsdcat);
179 /* Does this option take an argument? */
180 p = strchr(short_options, opt);
186 /* If it takes an argument, parse that. */
188 /* If arg is run-in, bsdcat->getopt_word already points to it. */
189 if (bsdcat->getopt_word[0] == '\0') {
190 /* Otherwise, pick up the next word. */
191 bsdcat->getopt_word = *bsdcat->argv;
192 if (bsdcat->getopt_word == NULL) {
194 "Option -%c requires an argument",
202 bsdcat->getopt_state = state_long;
203 long_prefix = "-W "; /* For clearer errors. */
205 bsdcat->getopt_state = state_next_word;
206 bsdcat->argument = bsdcat->getopt_word;
211 /* We're reading a long option, including -W long=arg convention. */
212 if (bsdcat->getopt_state == state_long) {
213 /* After this long option, we'll be starting a new word. */
214 bsdcat->getopt_state = state_next_word;
216 /* Option name ends at '=' if there is one. */
217 p = strchr(bsdcat->getopt_word, '=');
219 optlength = (size_t)(p - bsdcat->getopt_word);
220 bsdcat->argument = (char *)(uintptr_t)(p + 1);
222 optlength = strlen(bsdcat->getopt_word);
225 /* Search the table for an unambiguous match. */
226 for (popt = tar_longopts; popt->name != NULL; popt++) {
227 /* Short-circuit if first chars don't match. */
228 if (popt->name[0] != bsdcat->getopt_word[0])
230 /* If option is a prefix of name in table, record it.*/
231 if (strncmp(bsdcat->getopt_word, popt->name, optlength) == 0) {
232 match2 = match; /* Record up to two matches. */
234 /* If it's an exact match, we're done. */
235 if (strlen(popt->name) == optlength) {
236 match2 = NULL; /* Forget the others. */
242 /* Fail if there wasn't a unique match. */
245 "Option %s%s is not supported",
246 long_prefix, bsdcat->getopt_word);
249 if (match2 != NULL) {
251 "Ambiguous option %s%s (matches --%s and --%s)",
252 long_prefix, bsdcat->getopt_word, match->name, match2->name);
256 /* We've found a unique match; does it need an argument? */
257 if (match->required) {
258 /* Argument required: get next word if necessary. */
259 if (bsdcat->argument == NULL) {
260 bsdcat->argument = *bsdcat->argv;
261 if (bsdcat->argument == NULL) {
263 "Option %s%s requires an argument",
264 long_prefix, match->name);
271 /* Argument forbidden: fail if there is one. */
272 if (bsdcat->argument != NULL) {
274 "Option %s%s does not allow an argument",
275 long_prefix, match->name);
279 return (match->equivalent);