Remove the argpar_parse() API
[argpar.git] / argpar / argpar.h
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 * Create a parsing iterator with argpar_iter_create(), then
18 * repeatedly call argpar_iter_next() to access the parsing results,
19 * until one of:
20 *
21 * * There are no more arguments.
22 *
23 * * The argument parser encounters an error (for example, an unknown
24 * option).
25 *
26 * * You need to stop.
27 *
28 * The argpar parser parses the original arguments `argv` of which the
29 * count is `argc` using the sentinel-terminated (use
30 * `ARGPAR_OPT_DESCR_SENTINEL`) option descriptor array `descrs`.
31 *
32 * argpar considers ALL the elements of `argv`, including the first one,
33 * so that you would typically pass `argc - 1` and `&argv[1]` from what
34 * main() receives.
35 *
36 * The argpar parser supports:
37 *
38 * * Short options without an argument, possibly tied together:
39 *
40 * -f -auf -n
41 *
42 * * Short options with argument:
43 *
44 * -b 45 -f/mein/file -xyzhello
45 *
46 * * Long options without an argument:
47 *
48 * --five-guys --burger-king --pizza-hut --subway
49 *
50 * * Long options with arguments:
51 *
52 * --security enable --time=18.56
53 *
54 * * Non-option arguments (anything else).
55 *
56 * The argpar parser parses `-` and `--` as non-option arguments. A
57 * non-option argument cannot have the form of an option, for example if
58 * you need to pass the exact relative path `--component`. In that case,
59 * you would need to pass `./--component`. There's no generic way to
60 * escape `-` as of this version.
61 *
62 * argpar_iter_create() accepts duplicate options in `descrs` (it
63 * produces one item for each instance).
64 *
65 * A returned parsing item has the type `const struct argpar_item *`.
66 * Get the type (option or non-option) of an item with
67 * argpar_item_type(). Each item type has its set of dedicated methods
68 * (`argpar_item_opt_` and `argpar_item_non_opt_` prefixes).
69 *
70 * argpar_iter_next() produces the items in the same order that the
71 * original arguments were parsed, including non-option arguments. This
72 * means, for example, that for:
73 *
74 * --hello --count=23 /path/to/file -ab --type file magie
75 *
76 * argpar_iter_next() produces the following items, in this order:
77 *
78 * 1. Option item (`--hello`).
79 * 2. Option item (`--count` with argument `23`).
80 * 3. Non-option item (`/path/to/file`).
81 * 4. Option item (`-a`).
82 * 5. Option item (`-b`).
83 * 6. Option item (`--type` with argument `file`).
84 * 7. Non-option item (`magie`).
85 */
86
87 /* Sentinel for an option descriptor array */
88 #define ARGPAR_OPT_DESCR_SENTINEL { -1, '\0', NULL, false }
89
90 /*
91 * If argpar is used in some shared library, we don't want said library
92 * to export its symbols, so mark them as "hidden".
93 *
94 * On Windows, symbols are local unless explicitly exported; see
95 * <https://gcc.gnu.org/wiki/Visibility>.
96 */
97 #if defined(_WIN32) || defined(__CYGWIN__)
98 # define ARGPAR_HIDDEN
99 #else
100 # define ARGPAR_HIDDEN __attribute__((visibility("hidden")))
101 #endif
102
103 /* Forward-declaration for the opaque argpar iterator type */
104 struct argpar_iter;
105
106 /* Option descriptor */
107 struct argpar_opt_descr {
108 /* Numeric ID for this option */
109 const int id;
110
111 /* Short option character, or `\0` */
112 const char short_name;
113
114 /* Long option name (without the `--` prefix), or `NULL` */
115 const char * const long_name;
116
117 /* True if this option has an argument */
118 const bool with_arg;
119 };
120
121 /* Item type */
122 enum argpar_item_type {
123 /* Option */
124 ARGPAR_ITEM_TYPE_OPT,
125
126 /* Non-option */
127 ARGPAR_ITEM_TYPE_NON_OPT,
128 };
129
130 /* Forward-declaration for the opaque argpar parsing item type */
131 struct argpar_item;
132
133 /*
134 * Returns the type of the parsing item `item`.
135 */
136 ARGPAR_HIDDEN
137 enum argpar_item_type argpar_item_type(const struct argpar_item *item);
138
139 /*
140 * Returns the option descriptor of the option parsing item `item`.
141 */
142 ARGPAR_HIDDEN
143 const struct argpar_opt_descr *argpar_item_opt_descr(
144 const struct argpar_item *item);
145
146 /*
147 * Returns the argument of the option parsing item `item`, or `NULL` if
148 * none.
149 */
150 ARGPAR_HIDDEN
151 const char *argpar_item_opt_arg(const struct argpar_item *item);
152
153 /*
154 * Returns the complete argument, pointing to one of the entries of the
155 * original arguments (`argv`), of the non-option parsing item `item`.
156 */
157 ARGPAR_HIDDEN
158 const char *argpar_item_non_opt_arg(const struct argpar_item *item);
159
160 /*
161 * Returns the original index, within ALL the original arguments
162 * (`argv`), of the non-option parsing item `item`.
163 */
164 ARGPAR_HIDDEN
165 unsigned int argpar_item_non_opt_orig_index(const struct argpar_item *item);
166
167 /*
168 * Returns the index, within the non-option arguments, of the non-option
169 * parsing item `item`.
170 */
171 ARGPAR_HIDDEN
172 unsigned int argpar_item_non_opt_non_opt_index(const struct argpar_item *item);
173
174 /*
175 * Destroys `item`, as created by argpar_iter_next().
176 */
177 ARGPAR_HIDDEN
178 void argpar_item_destroy(const struct argpar_item *item);
179
180 /*
181 * Creates an argument parsing iterator.
182 *
183 * This function initializes the returned structure, but doesn't
184 * actually start parsing the arguments.
185 *
186 * `*argv` and `*descrs` must NOT change for the lifetime of the
187 * returned iterator (until you call argpar_iter_destroy()) and for the
188 * lifetime of any parsing item (until you call argpar_item_destroy())
189 * argpar_iter_next() creates for the returned iterator.
190 *
191 * Call argpar_iter_next() with the returned iterator to obtain the next
192 * parsing result (item).
193 */
194 ARGPAR_HIDDEN
195 struct argpar_iter *argpar_iter_create(unsigned int argc,
196 const char * const *argv,
197 const struct argpar_opt_descr *descrs);
198
199 /*
200 * Destroys `iter`, as returned by argpar_iter_create().
201 */
202 ARGPAR_HIDDEN
203 void argpar_iter_destroy(struct argpar_iter *iter);
204
205 /*
206 * Return type of argpar_iter_next().
207 */
208 enum argpar_iter_next_status {
209 ARGPAR_ITER_NEXT_STATUS_OK,
210 ARGPAR_ITER_NEXT_STATUS_END,
211 ARGPAR_ITER_NEXT_STATUS_ERROR_UNKNOWN_OPT,
212 ARGPAR_ITER_NEXT_STATUS_ERROR_MISSING_OPT_ARG,
213 ARGPAR_ITER_NEXT_STATUS_ERROR_UNEXPECTED_OPT_ARG,
214 ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY,
215 };
216
217 /*
218 * Parses and returns the next item from `iter`.
219 *
220 * On success, this function:
221 *
222 * * Sets `*item` to a parsing item which describes the next option
223 * or non-option argument.
224 *
225 * Destroy `*item` with argpar_item_destroy().
226 *
227 * * Returns `ARGPAR_ITER_NEXT_STATUS_OK`.
228 *
229 * If there are no more items to return, this function returns
230 * `ARGPAR_ITER_NEXT_STATUS_END`.
231 *
232 * On failure, this function:
233 *
234 * * Returns one of:
235 *
236 * `ARGPAR_ITER_NEXT_STATUS_ERROR_UNKNOWN_OPT`:
237 * Unknown option (not found in `descrs` as passed to
238 * argpar_iter_create() to create `iter`).
239 *
240 * `ARGPAR_ITER_NEXT_STATUS_ERROR_MISSING_OPT_ARG`:
241 * Missing option argument.
242 *
243 * `ARGPAR_ITER_NEXT_STATUS_ERROR_UNEXPECTED_OPT_ARG`:
244 * Unexpected option argument.
245 *
246 * `ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY`:
247 * Memory error.
248 *
249 * * Except for the `ARGPAR_ITER_NEXT_STATUS_ERROR_MEMORY` status,
250 * sets `*error`, if not `NULL`, to a descriptive error string.
251 * Free `*error` with free().
252 */
253 enum argpar_iter_next_status argpar_iter_next(
254 struct argpar_iter *iter, const struct argpar_item **item,
255 char **error);
256
257 /*
258 * Returns the number of ingested elements from `argv`, as passed to
259 * argpar_iter_create() to create `*iter`, that were required to produce
260 * the previously returned items.
261 */
262 ARGPAR_HIDDEN
263 unsigned int argpar_iter_ingested_orig_args(const struct argpar_iter *iter);
264
265 /*
266 * Destroys `_item` (`const struct argpar_item *`) and sets it to
267 * `NULL`.
268 */
269 #define ARGPAR_ITEM_DESTROY_AND_RESET(_item) \
270 { \
271 argpar_item_destroy(_item); \
272 _item = NULL; \
273 }
274
275 #endif /* ARGPAR_ARGPAR_H */
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