| 1 | /* |
| 2 | * SPDX-License-Identifier: MIT |
| 3 | * |
| 4 | * Copyright (c) 2019-2021 Philippe Proulx <pproulx@efficios.com> |
| 5 | * Copyright (c) 2020-2021 Simon Marchi <simon.marchi@efficios.com> |
| 6 | */ |
| 7 | |
| 8 | #ifndef ARGPAR_ARGPAR_H |
| 9 | #define ARGPAR_ARGPAR_H |
| 10 | |
| 11 | #include <stdbool.h> |
| 12 | |
| 13 | /* |
| 14 | * argpar is a library which provides facilities for command-line |
| 15 | * argument parsing. |
| 16 | * |
| 17 | * Two APIs are available: |
| 18 | * |
| 19 | * Iterator API: |
| 20 | * Create a parsing iterator with argpar_iter_create(), then |
| 21 | * repeatedly call argpar_iter_parse_next() to access the parsing |
| 22 | * results, until one of: |
| 23 | * |
| 24 | * * There are no more arguments. |
| 25 | * |
| 26 | * * The argument parser encounters an error (for example, an |
| 27 | * unknown option). |
| 28 | * |
| 29 | * * You need to stop. |
| 30 | * |
| 31 | * This API provides more parsing control than the next one. |
| 32 | * |
| 33 | * Single call API: |
| 34 | * Call argpar_parse(), which parses the arguments until one of: |
| 35 | * |
| 36 | * * There are no more arguments. |
| 37 | * |
| 38 | * * It encounters an argument parsing error. |
| 39 | * |
| 40 | * argpar_parse() returns a single array of parsing results. |
| 41 | * |
| 42 | * Both methods parse the arguments `argv` of which the count is `argc` |
| 43 | * using the sentinel-terminated (use `ARGPAR_OPT_DESCR_SENTINEL`) |
| 44 | * option descriptor array `descrs`. |
| 45 | * |
| 46 | * argpar considers ALL the elements of `argv`, including the first one, |
| 47 | * so that you would typically pass `argc - 1` and `&argv[1]` from what |
| 48 | * main() receives. |
| 49 | * |
| 50 | * The argpar parsers support: |
| 51 | * |
| 52 | * * Short options without an argument, possibly tied together: |
| 53 | * |
| 54 | * -f -auf -n |
| 55 | * |
| 56 | * * Short options with argument: |
| 57 | * |
| 58 | * -b 45 -f/mein/file -xyzhello |
| 59 | * |
| 60 | * * Long options without an argument: |
| 61 | * |
| 62 | * --five-guys --burger-king --pizza-hut --subway |
| 63 | * |
| 64 | * * Long options with arguments: |
| 65 | * |
| 66 | * --security enable --time=18.56 |
| 67 | * |
| 68 | * * Non-option arguments (anything else). |
| 69 | * |
| 70 | * The argpar parsers don't accept `-` or `--` as arguments. The latter |
| 71 | * means "end of options" for many command-line tools, but this library |
| 72 | * is all about keeping the order of the arguments, so it doesn't mean |
| 73 | * much to put them at the end. This has the side effect that a |
| 74 | * non-option argument cannot have the form of an option, for example if |
| 75 | * you need to pass the exact relative path `--component`. In that case, |
| 76 | * you would need to pass `./--component`. There's no generic way to |
| 77 | * escape `-` as of this version. |
| 78 | * |
| 79 | * Both argpar_iter_create() and argpar_parse() accept duplicate options |
| 80 | * (they produce one item for each instance). |
| 81 | * |
| 82 | * A returned parsing item has the type `struct argpar_item *`. Each |
| 83 | * item is to be casted to the appropriate type |
| 84 | * (`struct argpar_item_opt *` or `struct argpar_item_non_opt *`) |
| 85 | * depending on its `type` member. |
| 86 | * |
| 87 | * Both argpar_iter_create() and argpar_parse() produce the items in |
| 88 | * the same order that the arguments were parsed, including non-option |
| 89 | * arguments. This means, for example, that for: |
| 90 | * |
| 91 | * --hello --count=23 /path/to/file -ab --type file magie |
| 92 | * |
| 93 | * The produced items are, in this order: |
| 94 | * |
| 95 | * 1. Option item (`--hello`). |
| 96 | * 2. Option item (`--count` with argument `23`). |
| 97 | * 3. Non-option item (`/path/to/file`). |
| 98 | * 4. Option item (`-a`). |
| 99 | * 5. Option item (`-b`). |
| 100 | * 6. Option item (`--type` with argument `file`). |
| 101 | * 7. Non-option item (`magie`). |
| 102 | */ |
| 103 | |
| 104 | /* Sentinel for an option descriptor array */ |
| 105 | #define ARGPAR_OPT_DESCR_SENTINEL { -1, '\0', NULL, false } |
| 106 | |
| 107 | /* |
| 108 | * If argpar is used in some shared library, we don't want said library |
| 109 | * to export its symbols, so mark them as "hidden". |
| 110 | * |
| 111 | * On Windows, symbols are local unless explicitly exported; see |
| 112 | * <https://gcc.gnu.org/wiki/Visibility>. |
| 113 | */ |
| 114 | #if defined(_WIN32) || defined(__CYGWIN__) |
| 115 | # define ARGPAR_HIDDEN |
| 116 | #else |
| 117 | # define ARGPAR_HIDDEN __attribute__((visibility("hidden"))) |
| 118 | #endif |
| 119 | |
| 120 | /* Forward-declaration for the opaque type */ |
| 121 | struct argpar_iter; |
| 122 | |
| 123 | /* Option descriptor */ |
| 124 | struct argpar_opt_descr { |
| 125 | /* Numeric ID for this option */ |
| 126 | const int id; |
| 127 | |
| 128 | /* Short option character, or `\0` */ |
| 129 | const char short_name; |
| 130 | |
| 131 | /* Long option name (without `--`), or `NULL` */ |
| 132 | const char * const long_name; |
| 133 | |
| 134 | /* True if this option has an argument */ |
| 135 | const bool with_arg; |
| 136 | }; |
| 137 | |
| 138 | /* Item type */ |
| 139 | enum argpar_item_type { |
| 140 | /* Option */ |
| 141 | ARGPAR_ITEM_TYPE_OPT, |
| 142 | |
| 143 | /* Non-option */ |
| 144 | ARGPAR_ITEM_TYPE_NON_OPT, |
| 145 | }; |
| 146 | |
| 147 | /* Base item */ |
| 148 | struct argpar_item { |
| 149 | enum argpar_item_type type; |
| 150 | }; |
| 151 | |
| 152 | /* Option item */ |
| 153 | struct argpar_item_opt { |
| 154 | struct argpar_item base; |
| 155 | |
| 156 | /* Corresponding descriptor */ |
| 157 | const struct argpar_opt_descr *descr; |
| 158 | |
| 159 | /* Argument, or `NULL` if none */ |
| 160 | const char *arg; |
| 161 | }; |
| 162 | |
| 163 | /* Non-option item */ |
| 164 | struct argpar_item_non_opt { |
| 165 | struct argpar_item base; |
| 166 | |
| 167 | /* |
| 168 | * Complete argument, pointing to one of the entries of the |
| 169 | * original arguments (`argv`). |
| 170 | */ |
| 171 | const char *arg; |
| 172 | |
| 173 | /* Index of this argument amongst all original arguments (`argv`) */ |
| 174 | unsigned int orig_index; |
| 175 | |
| 176 | /* Index of this argument amongst other non-option arguments */ |
| 177 | unsigned int non_opt_index; |
| 178 | }; |
| 179 | |
| 180 | struct argpar_item_array { |
| 181 | const struct argpar_item **items; |
| 182 | |
| 183 | /* Number of used slots in `items` */ |
| 184 | unsigned int n_items; |
| 185 | |
| 186 | /* Number of allocated slots in `items` */ |
| 187 | unsigned int n_alloc; |
| 188 | }; |
| 189 | |
| 190 | /* What is returned by argpar_parse() */ |
| 191 | struct argpar_parse_ret { |
| 192 | /* |
| 193 | * Array of parsing items, or `NULL` on error. |
| 194 | * |
| 195 | * Do NOT destroy those items manually with |
| 196 | * argpar_iter_destroy(): call argpar_parse_ret_fini() to |
| 197 | * finalize the whole structure. |
| 198 | */ |
| 199 | struct argpar_item_array *items; |
| 200 | |
| 201 | /* Error string, or `NULL` if none */ |
| 202 | char *error; |
| 203 | |
| 204 | /* Number of original arguments (`argv`) ingested */ |
| 205 | unsigned int ingested_orig_args; |
| 206 | }; |
| 207 | |
| 208 | /* |
| 209 | * Parses arguments in `argv` until the end is reached or an error is |
| 210 | * encountered. |
| 211 | * |
| 212 | * On success, this function returns an array of items (field `items` of |
| 213 | * `struct argpar_parse_ret`). |
| 214 | * |
| 215 | * In the returned structure, `ingested_orig_args` is the number of |
| 216 | * ingested arguments within `argv` to produce the resulting array of |
| 217 | * items. |
| 218 | * |
| 219 | * If `fail_on_unknown_opt` is true, then on success |
| 220 | * `ingested_orig_args` is equal to `argc`. Otherwise, |
| 221 | * `ingested_orig_args` contains the number of original arguments until |
| 222 | * an unknown _option_ occurs. For example, with |
| 223 | * |
| 224 | * --great --white contact nuance --shark nuclear |
| 225 | * |
| 226 | * if `--shark` is not described within `descrs` and |
| 227 | * `fail_on_unknown_opt` is false, then `ingested_orig_args` is 4 (two |
| 228 | * options, two non-options), whereas `argc` is 6. |
| 229 | * |
| 230 | * This makes it possible to know where a command name is, for example. |
| 231 | * With those arguments: |
| 232 | * |
| 233 | * --verbose --stuff=23 do-something --specific-opt -f -b |
| 234 | * |
| 235 | * and the descriptors for `--verbose` and `--stuff` only, the function |
| 236 | * returns the `--verbose` and `--stuff` option items, the |
| 237 | * `do-something` non-option item, and that three original arguments |
| 238 | * were ingested. This means you can start the next argument parsing |
| 239 | * stage, with option descriptors depending on the command name, at |
| 240 | * `&argv[3]`. |
| 241 | * |
| 242 | * Note that `ingested_orig_args` is not always equal to the number of |
| 243 | * returned items, as |
| 244 | * |
| 245 | * --hello -fdw |
| 246 | * |
| 247 | * for example contains two ingested original arguments, but four |
| 248 | * resulting items. |
| 249 | * |
| 250 | * On failure, the `items` member of the returned structure is `NULL`, |
| 251 | * and the `error` string member contains details about the error. |
| 252 | * |
| 253 | * Finalize the returned structure with argpar_parse_ret_fini(). |
| 254 | */ |
| 255 | ARGPAR_HIDDEN |
| 256 | struct argpar_parse_ret argpar_parse(unsigned int argc, |
| 257 | const char * const *argv, |
| 258 | const struct argpar_opt_descr *descrs, |
| 259 | bool fail_on_unknown_opt); |
| 260 | |
| 261 | /* |
| 262 | * Finalizes what argpar_parse() returns. |
| 263 | * |
| 264 | * You may call argpar_parse() multiple times with the same structure. |
| 265 | */ |
| 266 | ARGPAR_HIDDEN |
| 267 | void argpar_parse_ret_fini(struct argpar_parse_ret *ret); |
| 268 | |
| 269 | /* |
| 270 | * Creates an argument parsing iterator. |
| 271 | * |
| 272 | * This function initializes the returned structure, but doesn't |
| 273 | * actually start parsing the arguments. |
| 274 | * |
| 275 | * `*argv` and `*descrs` must NOT change for the lifetime of the |
| 276 | * returned iterator (until you call argpar_iter_destroy()). |
| 277 | * |
| 278 | * Call argpar_iter_parse_next() with the returned iterator to obtain |
| 279 | * the next parsing result (item). |
| 280 | */ |
| 281 | ARGPAR_HIDDEN |
| 282 | struct argpar_iter *argpar_iter_create(unsigned int argc, |
| 283 | const char * const *argv, |
| 284 | const struct argpar_opt_descr *descrs); |
| 285 | |
| 286 | /* |
| 287 | * Destroys `iter`, as returned by argpar_iter_create(). |
| 288 | */ |
| 289 | ARGPAR_HIDDEN |
| 290 | void argpar_iter_destroy(struct argpar_iter *iter); |
| 291 | |
| 292 | /* |
| 293 | * Return type of argpar_iter_parse_next(). |
| 294 | */ |
| 295 | enum argpar_iter_parse_next_status { |
| 296 | ARGPAR_ITER_PARSE_NEXT_STATUS_OK, |
| 297 | ARGPAR_ITER_PARSE_NEXT_STATUS_END, |
| 298 | ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT, |
| 299 | ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR, |
| 300 | }; |
| 301 | |
| 302 | /* |
| 303 | * Parses and returns the next item from `iter`. |
| 304 | * |
| 305 | * On success, this function sets `*item` to an item which describes the |
| 306 | * next option or non-option argument and returns |
| 307 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_OK`. Destroy `*item` with |
| 308 | * argpar_item_destroy(). |
| 309 | * |
| 310 | * If there are no more items to return, this function returns |
| 311 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_END`. |
| 312 | * |
| 313 | * On failure (status codes |
| 314 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR_UNKNOWN_OPT` and |
| 315 | * `ARGPAR_ITER_PARSE_NEXT_STATUS_ERROR`), this function sets `*error` |
| 316 | * to a descriptive error string. Free `*error` with free(). |
| 317 | * |
| 318 | * Create an argument parsing iterator with argpar_iter_create(). |
| 319 | */ |
| 320 | enum argpar_iter_parse_next_status argpar_iter_parse_next( |
| 321 | struct argpar_iter *iter, const struct argpar_item **item, |
| 322 | char **error); |
| 323 | |
| 324 | /* |
| 325 | * Returns the number of ingested elements from `argv`, as passed to |
| 326 | * argpar_iter_create() to create `*iter`, that were required to produce |
| 327 | * the previously returned items. |
| 328 | */ |
| 329 | ARGPAR_HIDDEN |
| 330 | unsigned int argpar_iter_get_ingested_orig_args(const struct argpar_iter *iter); |
| 331 | |
| 332 | /* |
| 333 | * Destroys `item`, as created by argpar_iter_parse_next(). |
| 334 | */ |
| 335 | ARGPAR_HIDDEN |
| 336 | void argpar_item_destroy(const struct argpar_item *item); |
| 337 | |
| 338 | /* |
| 339 | * Destroys `_item` (`const struct argpar_item *`) and sets it to |
| 340 | * `NULL`. |
| 341 | */ |
| 342 | #define ARGPAR_ITEM_DESTROY_AND_RESET(_item) \ |
| 343 | { \ |
| 344 | argpar_item_destroy(_item); \ |
| 345 | _item = NULL; \ |
| 346 | } |
| 347 | |
| 348 | #endif /* ARGPAR_ARGPAR_H */ |