| 1 | /* Copyright (c) 2012, Kim Gräsman |
| 2 | * All rights reserved. |
| 3 | * |
| 4 | * Redistribution and use in source and binary forms, with or without |
| 5 | * modification, are permitted provided that the following conditions are met: |
| 6 | * * Redistributions of source code must retain the above copyright notice, |
| 7 | * this list of conditions and the following disclaimer. |
| 8 | * * Redistributions in binary form must reproduce the above copyright notice, |
| 9 | * this list of conditions and the following disclaimer in the documentation |
| 10 | * and/or other materials provided with the distribution. |
| 11 | * * Neither the name of Kim Gräsman nor the names of contributors may be used |
| 12 | * to endorse or promote products derived from this software without specific |
| 13 | * prior written permission. |
| 14 | * |
| 15 | * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" |
| 16 | * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 17 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 18 | * ARE DISCLAIMED. IN NO EVENT SHALL KIM GRÄSMAN BE LIABLE FOR ANY DIRECT, |
| 19 | * INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
| 20 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
| 21 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND |
| 22 | * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| 23 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| 24 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| 25 | */ |
| 26 | |
| 27 | #include "getopt.h" |
| 28 | |
| 29 | #include <stddef.h> |
| 30 | #include <string.h> |
| 31 | |
| 32 | const int no_argument = 0; |
| 33 | const int required_argument = 1; |
| 34 | const int optional_argument = 2; |
| 35 | |
| 36 | char* optarg; |
| 37 | int optopt; |
| 38 | /* The variable optind [...] shall be initialized to 1 by the system. */ |
| 39 | int optind = 1; |
| 40 | int opterr; |
| 41 | |
| 42 | static char* optcursor = NULL; |
| 43 | |
| 44 | /* Implemented based on [1] and [2] for optional arguments. |
| 45 | optopt is handled FreeBSD-style, per [3]. |
| 46 | Other GNU and FreeBSD extensions are purely accidental. |
| 47 | |
| 48 | [1] http://pubs.opengroup.org/onlinepubs/000095399/functions/getopt.html |
| 49 | [2] http://www.kernel.org/doc/man-pages/online/pages/man3/getopt.3.html |
| 50 | [3] http://www.freebsd.org/cgi/man.cgi?query=getopt&sektion=3&manpath=FreeBSD+9.0-RELEASE |
| 51 | */ |
| 52 | int getopt(int argc, char* const argv[], const char* optstring) { |
| 53 | int optchar = -1; |
| 54 | const char* optdecl = NULL; |
| 55 | |
| 56 | optarg = NULL; |
| 57 | opterr = 0; |
| 58 | optopt = 0; |
| 59 | |
| 60 | /* Unspecified, but we need it to avoid overrunning the argv bounds. */ |
| 61 | if (optind >= argc) |
| 62 | goto no_more_optchars; |
| 63 | |
| 64 | /* If, when getopt() is called argv[optind] is a null pointer, getopt() |
| 65 | shall return -1 without changing optind. */ |
| 66 | if (argv[optind] == NULL) |
| 67 | goto no_more_optchars; |
| 68 | |
| 69 | /* If, when getopt() is called *argv[optind] is not the character '-', |
| 70 | getopt() shall return -1 without changing optind. */ |
| 71 | if (*argv[optind] != '-') |
| 72 | goto no_more_optchars; |
| 73 | |
| 74 | /* If, when getopt() is called argv[optind] points to the string "-", |
| 75 | getopt() shall return -1 without changing optind. */ |
| 76 | if (strcmp(argv[optind], "-") == 0) |
| 77 | goto no_more_optchars; |
| 78 | |
| 79 | /* If, when getopt() is called argv[optind] points to the string "--", |
| 80 | getopt() shall return -1 after incrementing optind. */ |
| 81 | if (strcmp(argv[optind], "--") == 0) { |
| 82 | ++optind; |
| 83 | goto no_more_optchars; |
| 84 | } |
| 85 | |
| 86 | if (optcursor == NULL || *optcursor == '\0') |
| 87 | optcursor = argv[optind] + 1; |
| 88 | |
| 89 | optchar = *optcursor; |
| 90 | |
| 91 | /* FreeBSD: The variable optopt saves the last known option character |
| 92 | returned by getopt(). */ |
| 93 | optopt = optchar; |
| 94 | |
| 95 | /* The getopt() function shall return the next option character (if one is |
| 96 | found) from argv that matches a character in optstring, if there is |
| 97 | one that matches. */ |
| 98 | optdecl = strchr(optstring, optchar); |
| 99 | if (optdecl) { |
| 100 | /* [I]f a character is followed by a colon, the option takes an |
| 101 | argument. */ |
| 102 | if (optdecl[1] == ':') { |
| 103 | optarg = ++optcursor; |
| 104 | if (*optarg == '\0') { |
| 105 | /* GNU extension: Two colons mean an option takes an |
| 106 | optional arg; if there is text in the current argv-element |
| 107 | (i.e., in the same word as the option name itself, for example, |
| 108 | "-oarg"), then it is returned in optarg, otherwise optarg is set |
| 109 | to zero. */ |
| 110 | if (optdecl[2] != ':') { |
| 111 | /* If the option was the last character in the string pointed to by |
| 112 | an element of argv, then optarg shall contain the next element |
| 113 | of argv, and optind shall be incremented by 2. If the resulting |
| 114 | value of optind is greater than argc, this indicates a missing |
| 115 | option-argument, and getopt() shall return an error indication. |
| 116 | |
| 117 | Otherwise, optarg shall point to the string following the |
| 118 | option character in that element of argv, and optind shall be |
| 119 | incremented by 1. |
| 120 | */ |
| 121 | if (++optind < argc) { |
| 122 | optarg = argv[optind]; |
| 123 | } else { |
| 124 | /* If it detects a missing option-argument, it shall return the |
| 125 | colon character ( ':' ) if the first character of optstring |
| 126 | was a colon, or a question-mark character ( '?' ) otherwise. |
| 127 | */ |
| 128 | optarg = NULL; |
| 129 | optchar = (optstring[0] == ':') ? ':' : '?'; |
| 130 | } |
| 131 | } else { |
| 132 | optarg = NULL; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | optcursor = NULL; |
| 137 | } |
| 138 | } else { |
| 139 | /* If getopt() encounters an option character that is not contained in |
| 140 | optstring, it shall return the question-mark ( '?' ) character. */ |
| 141 | optchar = '?'; |
| 142 | } |
| 143 | |
| 144 | if (optcursor == NULL || *++optcursor == '\0') |
| 145 | ++optind; |
| 146 | |
| 147 | return optchar; |
| 148 | |
| 149 | no_more_optchars: |
| 150 | optcursor = NULL; |
| 151 | return -1; |
| 152 | } |
| 153 | |
| 154 | /* Implementation based on [1]. |
| 155 | |
| 156 | [1] http://www.kernel.org/doc/man-pages/online/pages/man3/getopt.3.html |
| 157 | */ |
| 158 | int getopt_long(int argc, char* const argv[], const char* optstring, |
| 159 | const struct option* longopts, int* longindex) { |
| 160 | const struct option* o = longopts; |
| 161 | const struct option* match = NULL; |
| 162 | int num_matches = 0; |
| 163 | size_t argument_name_length = 0; |
| 164 | const char* current_argument = NULL; |
| 165 | int retval = -1; |
| 166 | |
| 167 | optarg = NULL; |
| 168 | optopt = 0; |
| 169 | |
| 170 | if (optind >= argc) |
| 171 | return -1; |
| 172 | |
| 173 | if (strlen(argv[optind]) < 3 || strncmp(argv[optind], "--", 2) != 0) |
| 174 | return getopt(argc, argv, optstring); |
| 175 | |
| 176 | /* It's an option; starts with -- and is longer than two chars. */ |
| 177 | current_argument = argv[optind] + 2; |
| 178 | argument_name_length = strcspn(current_argument, "="); |
| 179 | for (; o->name; ++o) { |
| 180 | if (strncmp(o->name, current_argument, argument_name_length) == 0) { |
| 181 | match = o; |
| 182 | ++num_matches; |
| 183 | } |
| 184 | } |
| 185 | |
| 186 | if (num_matches == 1) { |
| 187 | /* If longindex is not NULL, it points to a variable which is set to the |
| 188 | index of the long option relative to longopts. */ |
| 189 | if (longindex) |
| 190 | *longindex = (int) (match - longopts); |
| 191 | |
| 192 | /* If flag is NULL, then getopt_long() shall return val. |
| 193 | Otherwise, getopt_long() returns 0, and flag shall point to a variable |
| 194 | which shall be set to val if the option is found, but left unchanged if |
| 195 | the option is not found. */ |
| 196 | if (match->flag) |
| 197 | *(match->flag) = match->val; |
| 198 | |
| 199 | retval = match->flag ? 0 : match->val; |
| 200 | |
| 201 | if (match->has_arg != no_argument) { |
| 202 | optarg = strchr(argv[optind], '='); |
| 203 | if (optarg != NULL) |
| 204 | ++optarg; |
| 205 | |
| 206 | if (match->has_arg == required_argument) { |
| 207 | /* Only scan the next argv for required arguments. Behavior is not |
| 208 | specified, but has been observed with Ubuntu and Mac OSX. */ |
| 209 | if (optarg == NULL && ++optind < argc) { |
| 210 | optarg = argv[optind]; |
| 211 | } |
| 212 | |
| 213 | if (optarg == NULL) |
| 214 | retval = ':'; |
| 215 | } |
| 216 | } else if (strchr(argv[optind], '=')) { |
| 217 | /* An argument was provided to a non-argument option. |
| 218 | I haven't seen this specified explicitly, but both GNU and BSD-based |
| 219 | implementations show this behavior. |
| 220 | */ |
| 221 | retval = '?'; |
| 222 | } |
| 223 | } else { |
| 224 | /* Unknown option or ambiguous match. */ |
| 225 | retval = '?'; |
| 226 | } |
| 227 | |
| 228 | ++optind; |
| 229 | return retval; |
| 230 | } |