3 * $Id: mdwopt.h,v 1.1 1999/05/05 19:23:47 mdw Exp $
5 * Options parsing, similar to GNU @getopt_long@
7 * (c) 1996 Mark Wooding
10 /*----- Licensing 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 Library General Public License as
16 * published by the Free Software Foundation; either version 2 of the
17 * License, or (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 Library General Public License for more details.
24 * You should have received a copy of the GNU Library General Public
25 * License along with `mdwopt'; if not, write to the Free Software
26 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
29 /*----- Revision history --------------------------------------------------*
32 * Revision 1.1 1999/05/05 19:23:47 mdw
35 * --- Previous lives ---
38 * Revision 1.5 1997/08/09 20:27:59 mdw
39 * Fix spelling of `Licensing'.
41 * Revision 1.4 1997/07/29 21:11:49 mdw
42 * Fixed address of the FSF.
44 * Revision 1.3 1996/12/31 19:41:33 mdw
47 * Revision 1.2 1996/11/23 00:47:25 mdw
48 * Added `MdwOpt' object from the `anagram' source code.
50 * Revision 1.1 1996/09/24 18:01:43 mdw
58 /*----- Options handling structures ---------------------------------------*/
64 /* --- @mdwopt_data@ --- *
66 * Contains all the information needed by the @mdwopt@ routine to do its
71 /* --- Public variables --- */
73 char *arg
; /* Arg of current option, or 0 */
74 int opt
; /* Value of current option */
75 int ind
; /* 0 for init, index when done */
76 int err
; /* Set nonzero for error messages */
77 char *prog
; /* Program name (from @argv[0]@) */
79 /* --- Private variables --- *
81 * Don't play with these, please.
84 char *list
; /* Current short options pointer */
85 int next
; /* Next argument, unpermuted */
86 int order
; /* Ordering of options, flags */
87 char *env
; /* Where we are in the env var */
88 char *estart
; /* Pointer to env var buffer */
92 /*----- Global variables --------------------------------------------------*/
94 extern mdwopt_data mdwopt_global
; /* The default global data */
96 /* --- For compatibility with older programs (and prettiness) --- *
98 * The macros here access the global structure defined above. I consider it
99 * to be perfectly acceptable to use these macros in new code, because it
100 * looks nicer than playing with @mdwopt_global@.
103 #define optarg (mdwopt_global.arg) /* Argument of current option */
104 #define optopt (mdwopt_global.opt) /* Code of current option */
105 #define opterr (mdwopt_global.err) /* Zero to report error messages */
106 #define optind (mdwopt_global.ind) /* Index of first non-option */
107 #define optprog (mdwopt_global.prog) /* Pointer to program name */
109 /*----- Type definitions --------------------------------------------------*/
111 /* --- Long options definition table --- */
114 const char *name
; /* Name of the long option */
115 int has_arg
; /* Does it have an argument? */
116 int *flag
; /* Address of flag variable */
117 int val
; /* Value to store/return */
120 /* --- Old-style names for argument flags in long options table --- */
123 no_argument
, /* No argument required */
124 required_argument
, /* User must specify argument */
125 optional_argument
/* Argument is optional */
128 /* --- New style flag names --- */
131 gFlag_argReq
= 1, /* Required argument */
132 gFlag_argOpt
= 2, /* Optional argument */
133 gFlag_switch
= 4, /* OR val into flag, don't store */
134 gFlag_negate
= 8, /* Allow long option to be negated */
135 gFlag__last_long_opt_flag
= 0 /* Dummy value */
139 gFlag_noLongs
= 1, /* Don't read long options */
140 gFlag_noShorts
= 2, /* Don't read short options */
141 gFlag_numbers
= 4, /* Read numeric options */
142 gFlag_negation
= 8, /* Allow `%|+|%' for negations */
143 gFlag_envVar
= 16, /* Parse options from env var */
144 gFlag_noProgName
= 32, /* Don't set @optprog@ */
145 gFlag_negNumber
= 64, /* Allow negated number options */
146 gFlag__last_mdwopt_flag
= 0 /* Dummy value */
150 gFlag_negated
= 256, /* Option flag was negated by user */
151 gFlag__last_return_flag
= 0 /* Dummy value */
154 /*----- Main code ---------------------------------------------------------*/
156 /* --- @mdwopt@ --- *
158 * Arguments: @int argc@ = number of command line arguments
159 * @char * const *argv@ = pointer to command line arguments
160 * @const char *shortopt@ = pointer to short options information
161 * @const struct option *longopts@ = pointer to long opts info
162 * @int *longind@ = where to store matched longopt
163 * @mdwopt_data *data@ = persistent state for the parser
164 * @int flags@ = various useful flags
166 * Returns: Value of option found next, or an error character, or
167 * @EOF@ for the last thing.
169 * Use: Reads options. The routine should be more-or-less compatible
170 * with standard getopts, although it provides many more
171 * features even than the standard GNU implementation.
173 * The precise manner of options parsing is determined by
174 * various flag settings, which are described below. By setting
175 * flag values appropriately, you can achieve behaviour very
176 * similar to most other getopt routines.
179 * How options parsing appears to users
181 * A command line consists of a number of `words' (which may
182 * contain spaces, according to various shell quoting
183 * conventions). A word may be an option, an argument to an
184 * option, or a non-option. An option begins with a special
185 * character, usually `%|-|%', although `%|+|%' is also used
186 * sometimes. As special exceptions, the word containing only a
187 * `%|-|%' is considered to be a non-option, since it usually
188 * represents standard input or output as a filename, and the
189 * word containing a double-dash `%|--|%' is used to mark all
190 * following words as being non-options regardless of their
193 * Traditionally, all words after the first non-option have been
194 * considered to be non-options automatically, so that options
195 * must be specified before filenames. However, this
196 * implementation can extract all the options from the command
197 * line regardless of their position. This can usually be
198 * disabled by setting one of the environment variables
199 * `%|POSIXLY_CORRECT|%' or `%|_POSIX_OPTION_ORDER|%'.
201 * There are two different styles of options: `short' and
204 * Short options are the sort which Unix has known for ages: an
205 * option is a single letter, preceded by a `%|-|%'. Short
206 * options can be joined together to save space (and possibly to
207 * make silly words): e.g., instead of giving options
208 * `%|-x.-y|%', a user could write `%|-xy|%'. Some short
209 * options can have arguments, which appear after the option
210 * letter, either immediately following, or in the next `word'
211 * (so an option with an argument could be written as
212 * `%|-o foo|%' or as `%|-ofoo|%'). Note that options with
213 * optional arguments must be written in the second style.
215 * When a short option controls a flag setting, it is sometimes
216 * possible to explicitly turn the flag off, as well as turning
217 * it on, (usually to override default options). This is
218 * usually done by using a `%|+|%' instead of a `%|-|%' to
219 * introduce the option.
221 * Long options, as popularised by the GNU utilities, are given
222 * long-ish memorable names, preceded by a double-dash `%|--|%'.
223 * Since their names are more than a single character, long
224 * options can't be combined in the same way as short options.
225 * Arguments to long options may be given either in the same
226 * `word', separated from the option name by an equals sign, or
227 * in the following `word'.
229 * Long option names can be abbreviated if necessary, as long
230 * as the abbreviation is unique. This means that options can
231 * have sensible and memorable names but still not require much
232 * typing from an experienced user.
234 * Like short options, long options can control flag settings.
235 * The options to manipulate these settings come in pairs: an
236 * option of the form `%|--set-flag|%' might set the flag, while
237 * an option of the form `%|--no-set-flag|%' might clear it.
239 * It is usual for applications to provide both short and long
240 * options with identical behaviour. Some applications with
241 * lots of options may only provide long options (although they
242 * will often be only two or three characters long). In this
243 * case, long options can be preceded with a single `%|-|%'
244 * character, and negated by a `%|+|%' character.
246 * Finally, some (older) programs accept arguments of the form
247 * `%%@.{"-"<number>}%%', to set some numerical parameter,
248 * typically a line count of some kind.
251 * How programs parse options
253 * An application parses its options by calling mdwopt
254 * repeatedly. Each time it is called, mdwopt returns a value
255 * describing the option just read, and stores information about
256 * the option in a data block. The value %$-1$% is returned
257 * when there are no more options to be read. The `%|?|%'
258 * character is returned when an error is encountered.
260 * Before starting to parse options, the value @data->ind@ must
261 * be set to 0 or 1. The value of @data->err@ can also be set,
262 * to choose whether errors are reported by mdwopt.
264 * The program's `@argc@' and `@argv@' arguments are passed to
265 * the options parser, so that it can read the command line. A
266 * flags word is also passed, allowing the program fine control
267 * over parsing. The flags are described above.
269 * Short options are described by a string, which once upon a
270 * time just contained the permitted option characters. Now the
271 * options string begins with a collection of flag characters,
272 * and various flag characters can be put after options
273 * characters to change their properties.
275 * If the first character of the short options string is
276 * `%|+|%', `%|-|%' or `%|!|%', the order in which options are
277 * read is modified, as follows:
279 * `%|+|%' forces the POSIX order to be used. As soon as a non-
280 * option is found, mdwopt returns %$-1$%.
282 * `%|-|%' makes mdwopt treat non-options as being `special'
283 * sorts of option. When a non-option word is found, the
284 * value 0 is returned, and the actual text of the word
285 * is stored as being the option's argument.
287 * `%|!|%' forces the default order to be used. The entire
288 * command line is scanned for options, which are
289 * returned in order. However, during this process,
290 * the options are moved in the @argv@ array, so that
291 * they appear before the non- options.
293 * A `%|:|%' character may be placed after the ordering flag (or
294 * at the very beginning if no ordering flag is given) which
295 * indicates that the character `%|:|%', rather than `%|?|%',
296 * should be returned if a missing argument error is detected.
298 * Each option in the string can be followed by a `%|+|%' sign,
299 * indicating that it can be negated, a `%|:|%' sign indicating
300 * that it requires an argument, or a `%|::|%' string,
301 * indicating an optional argument. Both `%|+|%' and `%|:|%' or
302 * `%|::|%' may be given, although the `%|+|%' must come first.
304 * If an option is found, the option character is returned to
305 * the caller. A pointer to an argument is stored in
306 * @data->arg@, or @NULL@ is stored if there was no argument.
307 * If a negated option was found, the option character is
308 * returned ORred with @gFlag_negated@ (bit 8 set).
310 * Long options are described in a table. Each entry in the
311 * table is of type @struct option@, and the table is terminated
312 * by an entry whose @name@ field is null. Each option has
313 * a flags word which, due to historical reasons, is called
314 * @has_arg@. This describes various properties of the option,
315 * such as what sort of argument it takes, and whether it can
318 * When mdwopt finds a long option, it looks the name up in the
319 * table. The index of the matching entry is stored in the
320 * @longind@ variable, passed to mdwopt (unless @longind@ is 0):
321 * a value of %$-1$% indicates that no long option was
322 * found. The behaviour is then dependent on the values in the
323 * table entry. If @flag@ is nonzero, it points to an integer
324 * to be modified by mdwopt. Usually the value in the @val@
325 * field is simply stored in the @flag@ variable. If the flag
326 * @gFlag_switch@ is set, however, the value is combined with
327 * the existing value of the flags using a bitwise OR. If
328 * @gFlag_negate@ is set, then the flag bit will be cleared if a
329 * matching negated long option is found. The value 0 is
332 * If @flag@ is zero, the value in @val@ is returned by mdwopt,
333 * possibly with bit 8 set if the option was negated.
335 * Arguments for long options are stored in @data->arg@, as
338 * Numeric options, if enabled, cause the value `%|#|%' to be
339 * returned, and the numeric value to be stored in @data->opt@.
341 * If the flag @gFlag_envVar@ is set on entry, options will be
342 * extracted from an environment variable whose name is built by
343 * capitalising all the letters of the program's name. (This
344 * allows a user to have different default settings for a
345 * program, by calling it through different symbolic links.) */
347 extern int mdwopt(int /*argc*/, char *const */
*argv*/
,
348 const char */
*shortopt*/
,
349 const struct option */
*longopts*/
, int */
*longind*/
,
350 mdwopt_data */
*data*/
, int /*flags*/);
352 /* --- Macros for more commonly used routines --- */
354 #define getopt(c, v, o) mdwopt(c, v, o, 0, 0, 0, gFlag_noLongs)
355 #define getopt_long(c, v, o, l, li) mdwopt(c, v, o, l, li, 0, 0)
356 #define getopt_long_only(c, v, o, l, li) \
357 mdwopt(c, v, o, l, li, 0, gFlag_noShorts)
363 /*----- C++ wrapper class -------------------------------------------------*/
367 /* --- Class: @MdwOpt@ --- *
371 * Methods: @MdwOpt@ -- construct a new mdwopt object with the given
372 * arguments. These are remembered for later use.
373 * @arg@ -- return the argument of the current option
374 * arguments. These are remembered for later use.
375 * @arg@ -- return the argument of the current option
376 * @opt@ -- return the value of the current option
377 * @ind@ -- return the index of the next unread argument
378 * @longind@ -- return index of current long option in table
379 * @errors@ -- return or set whether we report errors to the
381 * @prog@ -- return program name from @argv[0]@
382 * @next@ -- return next option read from the table
384 * Use: A simple C++ class for encapsulating the options parser.
385 * The methods are all nice and simple, and extremely similar
386 * to the normal C interface described above.
393 const char *shortopts
;
394 const struct option
*longopts
;
401 MdwOpt(int c
, char * const *v
, const char *so
,
402 const struct option
*lo
, int f
=0) :
403 argc(c
), argv(v
), shortopts(so
), longopts(lo
), flags(f
) {
408 const char *arg(void) const { return (data
.arg
); }
409 int opt(void) const { return (data
.opt
); }
410 int errors(void) const { return (data
.err
); }
411 int errors(int e
) { int oe
= data
.err
; data
.err
= e
; return (oe
); }
412 int ind(void) const { return (data
.ind
); }
413 int longind(void) const { return (long_ind
); }
414 const char *prog(void) const { return (data
.prog
); }
417 return (mdwopt(argc
, argv
, shortopts
,
418 longopts
, &long_ind
, &data
, flags
));
424 /*----- That's all, folks -------------------------------------------------*/