3 * $Id: mdwopt.h,v 1.1 1997/07/21 13:47:47 mdw Exp $
5 * Options parsing, similar to GNU @getopt_long@
7 * (c) 1996 Mark Wooding
10 /*----- Licencing notice --------------------------------------------------*
12 * This file is part of many programs.
14 * `mdwopt' is free software; you can redistribute it and/or modify
15 * it under the terms of the GNU General Public License as published by
16 * the Free Software Foundation; either version 2 of the License, or
17 * (at your option) any later version.
19 * `mdwopt' is distributed in the hope that it will be useful,
20 * but WITHOUT ANY WARRANTY; without even the implied warranty of
21 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
22 * GNU General Public License for more details.
24 * You should have received a copy of the GNU General Public License
25 * along with `mdwopt'; if not, write to the Free Software
26 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.1 1997/07/21 13:47:47 mdw
35 * Revision 1.4 1997/02/26 00:39:55 mdw
36 * Added GPL notice to the top. Slight formatting changes. Commented out
37 * arguments to functions.
39 * Revision 1.3 1996/12/31 19:41:33 mdw
42 * Revision 1.2 1996/11/23 00:47:25 mdw
43 * Added `MdwOpt' object from the `anagram' source code.
45 * Revision 1.1 1996/09/24 18:01:43 mdw
53 /*----- Options handling structures ---------------------------------------*/
59 /* --- @mdwopt_data@ --- *
61 * Contains all the information needed by the @mdwopt@ routine to do its
66 /* --- Public variables --- */
68 char *arg
; /* Arg of current option, or 0 */
69 int opt
; /* Value of current option */
70 int ind
; /* 0 for init, index when done */
71 int err
; /* Set nonzero for error messages */
72 char *prog
; /* Program name (from @argv[0]@) */
74 /* --- Private variables --- *
76 * Don't play with these, please.
79 char *list
; /* Current short options pointer */
80 int next
; /* Next argument, unpermuted */
81 int order
; /* Ordering of options, flags */
82 char *env
; /* Where we are in the env var */
83 char *estart
; /* Pointer to env var buffer */
87 /*----- Global variables --------------------------------------------------*/
89 extern mdwopt_data mdwopt_global
; /* The default global data */
91 /* --- For compatibility with older programs (and prettiness) --- *
93 * The macros here access the global structure defined above. I consider it
94 * to be perfectly acceptable to use these macros in new code, because it
95 * looks nicer than playing with @mdwopt_global@.
98 #define optarg (mdwopt_global.arg) /* Argument of current option */
99 #define optopt (mdwopt_global.opt) /* Code of current option */
100 #define opterr (mdwopt_global.err) /* Zero to report error messages */
101 #define optind (mdwopt_global.ind) /* Index of first non-option */
102 #define optprog (mdwopt_global.prog) /* Pointer to program name */
104 /*----- Type definitions --------------------------------------------------*/
106 /* --- Long options definition table --- */
109 const char *name
; /* Name of the long option */
110 int has_arg
; /* Does it have an argument? */
111 int *flag
; /* Address of flag variable */
112 int val
; /* Value to store/return */
115 /* --- Old-style names for argument flags in long options table --- */
118 no_argument
, /* No argument required */
119 required_argument
, /* User must specify argument */
120 optional_argument
/* Argument is optional */
123 /* --- New style flag names --- */
126 gFlag_argReq
= 1, /* Required argument */
127 gFlag_argOpt
= 2, /* Optional argument */
128 gFlag_switch
= 4, /* OR val into flag, don't store */
129 gFlag_negate
= 8, /* Allow long option to be negated */
130 gFlag__last_long_opt_flag
= 0 /* Dummy value */
134 gFlag_noLongs
= 1, /* Don't read long options */
135 gFlag_noShorts
= 2, /* Don't read short options */
136 gFlag_numbers
= 4, /* Read numeric options */
137 gFlag_negation
= 8, /* Allow `%|+|%' for negations */
138 gFlag_envVar
= 16, /* Parse options from env var */
139 gFlag_noProgName
= 32, /* Don't set @optprog@ */
140 gFlag_negNumber
= 64, /* Allow negated number options */
141 gFlag__last_mdwopt_flag
= 0 /* Dummy value */
145 gFlag_negated
= 256, /* Option flag was negated by user */
146 gFlag__last_return_flag
= 0 /* Dummy value */
149 /*----- Main code ---------------------------------------------------------*/
151 /* --- @mdwopt@ --- *
153 * Arguments: @int argc@ = number of command line arguments
154 * @char * const *argv@ = pointer to command line arguments
155 * @const char *shortopt@ = pointer to short options information
156 * @const struct option *longopts@ = pointer to long opts info
157 * @int *longind@ = where to store matched longopt
158 * @mdwopt_data *data@ = persistent state for the parser
159 * @int flags@ = various useful flags
161 * Returns: Value of option found next, or an error character, or
162 * @EOF@ for the last thing.
164 * Use: Reads options. The routine should be more-or-less compatible
165 * with standard getopts, although it provides many more
166 * features even than the standard GNU implementation.
168 * The precise manner of options parsing is determined by
169 * various flag settings, which are described below. By setting
170 * flag values appropriately, you can achieve behaviour very
171 * similar to most other getopt routines.
174 * How options parsing appears to users
176 * A command line consists of a number of `words' (which may
177 * contain spaces, according to various shell quoting
178 * conventions). A word may be an option, an argument to an
179 * option, or a non-option. An option begins with a special
180 * character, usually `%|-|%', although `%|+|%' is also used
181 * sometimes. As special exceptions, the word containing only a
182 * `%|-|%' is considered to be a non-option, since it usually
183 * represents standard input or output as a filename, and the
184 * word containing a double-dash `%|--|%' is used to mark all
185 * following words as being non-options regardless of their
188 * Traditionally, all words after the first non-option have been
189 * considered to be non-options automatically, so that options
190 * must be specified before filenames. However, this
191 * implementation can extract all the options from the command
192 * line regardless of their position. This can usually be
193 * disabled by setting one of the environment variables
194 * `%|POSIXLY_CORRECT|%' or `%|_POSIX_OPTION_ORDER|%'.
196 * There are two different styles of options: `short' and
199 * Short options are the sort which Unix has known for ages: an
200 * option is a single letter, preceded by a `%|-|%'. Short
201 * options can be joined together to save space (and possibly to
202 * make silly words): e.g., instead of giving options
203 * `%|-x.-y|%', a user could write `%|-xy|%'. Some short
204 * options can have arguments, which appear after the option
205 * letter, either immediately following, or in the next `word'
206 * (so an option with an argument could be written as
207 * `%|-o foo|%' or as `%|-ofoo|%'). Note that options with
208 * optional arguments must be written in the second style.
210 * When a short option controls a flag setting, it is sometimes
211 * possible to explicitly turn the flag off, as well as turning
212 * it on, (usually to override default options). This is
213 * usually done by using a `%|+|%' instead of a `%|-|%' to
214 * introduce the option.
216 * Long options, as popularised by the GNU utilities, are given
217 * long-ish memorable names, preceded by a double-dash `%|--|%'.
218 * Since their names are more than a single character, long
219 * options can't be combined in the same way as short options.
220 * Arguments to long options may be given either in the same
221 * `word', separated from the option name by an equals sign, or
222 * in the following `word'.
224 * Long option names can be abbreviated if necessary, as long
225 * as the abbreviation is unique. This means that options can
226 * have sensible and memorable names but still not require much
227 * typing from an experienced user.
229 * Like short options, long options can control flag settings.
230 * The options to manipulate these settings come in pairs: an
231 * option of the form `%|--set-flag|%' might set the flag, while
232 * an option of the form `%|--no-set-flag|%' might clear it.
234 * It is usual for applications to provide both short and long
235 * options with identical behaviour. Some applications with
236 * lots of options may only provide long options (although they
237 * will often be only two or three characters long). In this
238 * case, long options can be preceded with a single `%|-|%'
239 * character, and negated by a `%|+|%' character.
241 * Finally, some (older) programs accept arguments of the form
242 * `%%@.{"-"<number>}%%', to set some numerical parameter,
243 * typically a line count of some kind.
246 * How programs parse options
248 * An application parses its options by calling mdwopt
249 * repeatedly. Each time it is called, mdwopt returns a value
250 * describing the option just read, and stores information about
251 * the option in a data block. The value %$-1$% is returned
252 * when there are no more options to be read. The `%|?|%'
253 * character is returned when an error is encountered.
255 * Before starting to parse options, the value @data->ind@ must
256 * be set to 0 or 1. The value of @data->err@ can also be set,
257 * to choose whether errors are reported by mdwopt.
259 * The program's `@argc@' and `@argv@' arguments are passed to
260 * the options parser, so that it can read the command line. A
261 * flags word is also passed, allowing the program fine control
262 * over parsing. The flags are described above.
264 * Short options are described by a string, which once upon a
265 * time just contained the permitted option characters. Now the
266 * options string begins with a collection of flag characters,
267 * and various flag characters can be put after options
268 * characters to change their properties.
270 * If the first character of the short options string is
271 * `%|+|%', `%|-|%' or `%|!|%', the order in which options are
272 * read is modified, as follows:
274 * `%|+|%' forces the POSIX order to be used. As soon as a non-
275 * option is found, mdwopt returns %$-1$%.
277 * `%|-|%' makes mdwopt treat non-options as being `special'
278 * sorts of option. When a non-option word is found, the
279 * value 0 is returned, and the actual text of the word
280 * is stored as being the option's argument.
282 * `%|!|%' forces the default order to be used. The entire
283 * command line is scanned for options, which are
284 * returned in order. However, during this process,
285 * the options are moved in the @argv@ array, so that
286 * they appear before the non- options.
288 * A `%|:|%' character may be placed after the ordering flag (or
289 * at the very beginning if no ordering flag is given) which
290 * indicates that the character `%|:|%', rather than `%|?|%',
291 * should be returned if a missing argument error is detected.
293 * Each option in the string can be followed by a `%|+|%' sign,
294 * indicating that it can be negated, a `%|:|%' sign indicating
295 * that it requires an argument, or a `%|::|%' string,
296 * indicating an optional argument. Both `%|+|%' and `%|:|%' or
297 * `%|::|%' may be given, although the `%|+|%' must come first.
299 * If an option is found, the option character is returned to
300 * the caller. A pointer to an argument is stored in
301 * @data->arg@, or @NULL@ is stored if there was no argument.
302 * If a negated option was found, the option character is
303 * returned ORred with @gFlag_negated@ (bit 8 set).
305 * Long options are described in a table. Each entry in the
306 * table is of type @struct option@, and the table is terminated
307 * by an entry whose @name@ field is null. Each option has
308 * a flags word which, due to historical reasons, is called
309 * @has_arg@. This describes various properties of the option,
310 * such as what sort of argument it takes, and whether it can
313 * When mdwopt finds a long option, it looks the name up in the
314 * table. The index of the matching entry is stored in the
315 * @longind@ variable, passed to mdwopt (unless @longind@ is 0):
316 * a value of %$-1$% indicates that no long option was
317 * found. The behaviour is then dependent on the values in the
318 * table entry. If @flag@ is nonzero, it points to an integer
319 * to be modified by mdwopt. Usually the value in the @val@
320 * field is simply stored in the @flag@ variable. If the flag
321 * @gFlag_switch@ is set, however, the value is combined with
322 * the existing value of the flags using a bitwise OR. If
323 * @gFlag_negate@ is set, then the flag bit will be cleared if a
324 * matching negated long option is found. The value 0 is
327 * If @flag@ is zero, the value in @val@ is returned by mdwopt,
328 * possibly with bit 8 set if the option was negated.
330 * Arguments for long options are stored in @data->arg@, as
333 * Numeric options, if enabled, cause the value `%|#|%' to be
334 * returned, and the numeric value to be stored in @data->opt@.
336 * If the flag @gFlag_envVar@ is set on entry, options will be
337 * extracted from an environment variable whose name is built by
338 * capitalising all the letters of the program's name. (This
339 * allows a user to have different default settings for a
340 * program, by calling it through different symbolic links.) */
342 extern int mdwopt(int /*argc*/, char *const */
*argv*/
,
343 const char */
*shortopt*/
,
344 const struct option */
*longopts*/
, int */
*longind*/
,
345 mdwopt_data */
*data*/
, int /*flags*/);
347 /* --- Macros for more commonly used routines --- */
349 #define getopt(c, v, o) mdwopt(c, v, o, 0, 0, 0, gFlag_noLongs)
350 #define getopt_long(c, v, o, l, li) mdwopt(c, v, o, l, li, 0, 0)
351 #define getopt_long_only(c, v, o, l, li) \
352 mdwopt(c, v, o, l, li, 0, gFlag_noShorts)
358 /*----- C++ wrapper class -------------------------------------------------*/
362 /* --- Class: @MdwOpt@ --- *
366 * Methods: @MdwOpt@ -- construct a new mdwopt object with the given
367 * arguments. These are remembered for later use.
368 * @arg@ -- return the argument of the current option
369 * arguments. These are remembered for later use.
370 * @arg@ -- return the argument of the current option
371 * @opt@ -- return the value of the current option
372 * @ind@ -- return the index of the next unread argument
373 * @longind@ -- return index of current long option in table
374 * @errors@ -- return or set whether we report errors to the
376 * @prog@ -- return program name from @argv[0]@
377 * @next@ -- return next option read from the table
379 * Use: A simple C++ class for encapsulating the options parser.
380 * The methods are all nice and simple, and extremely similar
381 * to the normal C interface described above.
388 const char *shortopts
;
389 const struct option
*longopts
;
396 MdwOpt(int c
, char * const *v
, const char *so
,
397 const struct option
*lo
, int f
=0) :
398 argc(c
), argv(v
), shortopts(so
), longopts(lo
), flags(f
) {
403 const char *arg(void) const { return (data
.arg
); }
404 int opt(void) const { return (data
.opt
); }
405 int errors(void) const { return (data
.err
); }
406 int errors(int e
) { int oe
= data
.err
; data
.err
= e
; return (oe
); }
407 int ind(void) const { return (data
.ind
); }
408 int longind(void) const { return (long_ind
); }
409 const char *prog(void) const { return (data
.prog
); }
412 return (mdwopt(argc
, argv
, shortopts
,
413 longopts
, &long_ind
, &data
, flags
));
419 /*----- That's all, folks -------------------------------------------------*/