3 $Id: getopt.c,v 1.3 2000/11/08 19:57:39 guy Exp $
5 NOTE: getopt is now part of the C library, so if you don't know what
6 "Keep this file name-space clean" means, talk to roland@gnu.ai.mit.edu
9 Copyright (C) 1987, 88, 89, 90, 91, 92, 1993
10 Free Software Foundation, Inc.
12 This program is free software; you can redistribute it and/or modify it
13 under the terms of the GNU General Public License as published by the
14 Free Software Foundation; either version 2, or (at your option) any
17 This program is distributed in the hope that it will be useful,
18 but WITHOUT ANY WARRANTY; without even the implied warranty of
19 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20 GNU General Public License for more details.
22 You should have received a copy of the GNU General Public License
23 along with this program; if not, write to the Free Software
24 Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
32 /* This is a separate conditional since some stdc systems
33 reject `defined (const)'. */
39 /* This tells Alpha OSF/1 not to define a getopt prototype in <stdio.h>. */
46 /* Comment out all this code if we are using the GNU C Library, and are not
47 actually compiling the library itself. This code is part of the GNU C
48 Library, but also included in many other GNU distributions. Compiling
49 and linking in this code is a waste when using the GNU C library
50 (especially if it is a shared library). Rather than having every GNU
51 program understand `configure --with-gnu-libc' and omit the object files,
52 it is simpler to just do this in the source for each such file. */
54 #if defined (_LIBC) || !defined (__GNU_LIBRARY__)
57 /* This needs to come after some library #include
58 to get __GNU_LIBRARY__ defined. */
59 #ifdef __GNU_LIBRARY__
60 /* Don't include stdlib.h for non-GNU C libraries because some of them
61 contain conflicting prototypes for getopt. */
63 #endif /* GNU C library. */
65 /* If GETOPT_COMPAT is defined, `+' as well as `--' can introduce a
66 long-named option. Because this is not POSIX.2 compliant, it is
68 /* #define GETOPT_COMPAT */
70 /* This version of `getopt' appears to the caller like standard Unix `getopt'
71 but it behaves differently for the user, since it allows the user
72 to intersperse the options with the other arguments.
74 As `getopt' works, it permutes the elements of ARGV so that,
75 when it is done, all the options precede everything else. Thus
76 all application programs are extended to handle flexible argument order.
78 Setting the environment variable POSIXLY_CORRECT disables permutation.
79 Then the behavior is completely standard.
81 GNU application programs can use a third alternative mode in which
82 they can distinguish the relative order of options and other arguments. */
86 /* For communication from `getopt' to the caller.
87 When `getopt' finds an option that takes an argument,
88 the argument value is returned here.
89 Also, when `ordering' is RETURN_IN_ORDER,
90 each non-option ARGV-element is returned here. */
94 /* Index in ARGV of the next element to be scanned.
95 This is used for communication to and from the caller
96 and for communication between successive calls to `getopt'.
98 On entry to `getopt', zero means this is the first call; initialize.
100 When `getopt' returns EOF, this is the index of the first of the
101 non-option elements that the caller should itself scan.
103 Otherwise, `optind' communicates from one call to the next
104 how much of ARGV has been scanned so far. */
106 /* XXX 1003.2 says this must be 1 before any call. */
109 /* The next char to be scanned in the option-element
110 in which the last option character we returned was found.
111 This allows us to pick up the scan where we left off.
113 If this is zero, or a null string, it means resume the scan
114 by advancing to the next ARGV-element. */
116 static char *nextchar;
118 /* Callers store zero here to inhibit the error message
119 for unrecognized options. */
123 /* Set to an option character which was unrecognized.
124 This must be initialized on some systems to avoid linking in the
125 system's own getopt implementation. */
129 /* Describe how to deal with options that follow non-option ARGV-elements.
131 If the caller did not specify anything,
132 the default is REQUIRE_ORDER if the environment variable
133 POSIXLY_CORRECT is defined, PERMUTE otherwise.
135 REQUIRE_ORDER means don't recognize them as options;
136 stop option processing when the first non-option is seen.
137 This is what Unix does.
138 This mode of operation is selected by either setting the environment
139 variable POSIXLY_CORRECT, or using `+' as the first character
140 of the list of option characters.
142 PERMUTE is the default. We permute the contents of ARGV as we scan,
143 so that eventually all the non-options are at the end. This allows options
144 to be given in any order, even with programs that were not written to
147 RETURN_IN_ORDER is an option available to programs that were written
148 to expect options and other ARGV-elements in any order and that care about
149 the ordering of the two. We describe each non-option ARGV-element
150 as if it were the argument of an option with character code 1.
151 Using `-' as the first character of the list of option characters
152 selects this mode of operation.
154 The special argument `--' forces an end of option-scanning regardless
155 of the value of `ordering'. In the case of RETURN_IN_ORDER, only
156 `--' can cause `getopt' to return EOF with `optind' != ARGC. */
160 REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
163 #ifdef __GNU_LIBRARY__
164 /* We want to avoid inclusion of string.h with non-GNU libraries
165 because there are many ways it can cause trouble.
166 On some systems, it contains special magic macros that don't work
169 #define my_index strchr
172 /* Avoid depending on library functions or files
173 whose names are inconsistent. */
191 /* If using GCC, we can safely declare strlen this way.
192 If not using GCC, it is ok not to declare it.
193 (Supposedly there are some machines where it might get a warning,
194 but changing this conditional to __STDC__ is too risky.) */
201 extern size_t strlen (const char *);
204 #endif /* GNU C library. */
206 /* Handle permutation of arguments. */
208 /* Describe the part of ARGV that contains non-options that have
209 been skipped. `first_nonopt' is the index in ARGV of the first of them;
210 `last_nonopt' is the index after the last of them. */
212 static int first_nonopt;
213 static int last_nonopt;
215 /* Exchange two adjacent subsequences of ARGV.
216 One subsequence is elements [first_nonopt,last_nonopt)
217 which contains all the non-options that have been skipped so far.
218 The other is elements [last_nonopt,optind), which contains all
219 the options processed since those non-options were skipped.
221 `first_nonopt' and `last_nonopt' are relocated so that they describe
222 the new indices of the non-options in ARGV after they are moved. */
228 int bottom = first_nonopt;
229 int middle = last_nonopt;
233 /* Exchange the shorter segment with the far end of the longer segment.
234 That puts the shorter segment into the right place.
235 It leaves the longer segment in the right place overall,
236 but it consists of two parts that need to be swapped next. */
238 while (top > middle && middle > bottom)
240 if (top - middle > middle - bottom)
242 /* Bottom segment is the short one. */
243 int len = middle - bottom;
246 /* Swap it with the top part of the top segment. */
247 for (i = 0; i < len; i++)
249 tem = argv[bottom + i];
250 argv[bottom + i] = argv[top - (middle - bottom) + i];
251 argv[top - (middle - bottom) + i] = tem;
253 /* Exclude the moved bottom segment from further swapping. */
258 /* Top segment is the short one. */
259 int len = top - middle;
262 /* Swap it with the bottom part of the bottom segment. */
263 for (i = 0; i < len; i++)
265 tem = argv[bottom + i];
266 argv[bottom + i] = argv[middle + i];
267 argv[middle + i] = tem;
269 /* Exclude the moved top segment from further swapping. */
274 /* Update records for the slots the non-options now occupy. */
276 first_nonopt += (optind - last_nonopt);
277 last_nonopt = optind;
280 /* Scan elements of ARGV (whose length is ARGC) for option characters
283 If an element of ARGV starts with '-', and is not exactly "-" or "--",
284 then it is an option element. The characters of this element
285 (aside from the initial '-') are option characters. If `getopt'
286 is called repeatedly, it returns successively each of the option characters
287 from each of the option elements.
289 If `getopt' finds another option character, it returns that character,
290 updating `optind' and `nextchar' so that the next call to `getopt' can
291 resume the scan with the following option character or ARGV-element.
293 If there are no more option characters, `getopt' returns `EOF'.
294 Then `optind' is the index in ARGV of the first ARGV-element
295 that is not an option. (The ARGV-elements have been permuted
296 so that those that are not options now come last.)
298 OPTSTRING is a string containing the legitimate option characters.
299 If an option character is seen that is not listed in OPTSTRING,
300 return '?' after printing an error message. If you set `opterr' to
301 zero, the error message is suppressed but we still return '?'.
303 If a char in OPTSTRING is followed by a colon, that means it wants an arg,
304 so the following text in the same ARGV-element, or the text of the following
305 ARGV-element, is returned in `optarg'. Two colons mean an option that
306 wants an optional arg; if there is text in the current ARGV-element,
307 it is returned in `optarg', otherwise `optarg' is set to zero.
309 If OPTSTRING starts with `-' or `+', it requests different methods of
310 handling the non-option ARGV-elements.
311 See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.
313 Long-named options begin with `--' instead of `-'.
314 Their names may be abbreviated as long as the abbreviation is unique
315 or is an exact match for some defined option. If they have an
316 argument, it follows the option name in the same ARGV-element, separated
317 from the option name by a `=', or else the in next ARGV-element.
318 When `getopt' finds a long-named option, it returns 0 if that option's
319 `flag' field is nonzero, the value of the option's `val' field
320 if the `flag' field is zero.
322 The elements of ARGV aren't really const, because we permute them.
323 But we pretend they're const in the prototype to be compatible
326 LONGOPTS is a vector of `struct option' terminated by an
327 element containing a name which is zero.
329 LONGIND returns the index in LONGOPT of the long-named option found.
330 It is only valid when a long-named option has been found by the most
333 If LONG_ONLY is nonzero, '-' as well as '--' can introduce
334 long-named options. */
337 _getopt_internal (argc, argv, optstring, longopts, longind, long_only)
340 const char *optstring;
341 const struct option *longopts;
349 /* Initialize the internal data when the first call is made.
350 Start processing options with ARGV-element 1 (since ARGV-element 0
351 is the program name); the sequence of previously skipped
352 non-option ARGV-elements is empty. */
356 first_nonopt = last_nonopt = optind = 1;
360 /* Determine how to handle the ordering of options and nonoptions. */
362 if (optstring[0] == '-')
364 ordering = RETURN_IN_ORDER;
367 else if (optstring[0] == '+')
369 ordering = REQUIRE_ORDER;
372 else if (getenv ("POSIXLY_CORRECT") != NULL)
373 ordering = REQUIRE_ORDER;
378 if (nextchar == NULL || *nextchar == '\0')
380 if (ordering == PERMUTE)
382 /* If we have just processed some options following some non-options,
383 exchange them so that the options come first. */
385 if (first_nonopt != last_nonopt && last_nonopt != optind)
386 exchange ((char **) argv);
387 else if (last_nonopt != optind)
388 first_nonopt = optind;
390 /* Now skip any additional non-options
391 and extend the range of non-options previously skipped. */
394 && (argv[optind][0] != '-' || argv[optind][1] == '\0')
397 || argv[optind][0] != '+' || argv[optind][1] == '\0')
398 #endif /* GETOPT_COMPAT */
401 last_nonopt = optind;
404 /* Special ARGV-element `--' means premature end of options.
405 Skip it like a null option,
406 then exchange with previous non-options as if it were an option,
407 then skip everything else like a non-option. */
409 if (optind != argc && !strcmp (argv[optind], "--"))
413 if (first_nonopt != last_nonopt && last_nonopt != optind)
414 exchange ((char **) argv);
415 else if (first_nonopt == last_nonopt)
416 first_nonopt = optind;
422 /* If we have done all the ARGV-elements, stop the scan
423 and back over any non-options that we skipped and permuted. */
427 /* Set the next-arg-index to point at the non-options
428 that we previously skipped, so the caller will digest them. */
429 if (first_nonopt != last_nonopt)
430 optind = first_nonopt;
434 /* If we have come to a non-option and did not permute it,
435 either stop the scan or describe it to the caller and pass it by. */
437 if ((argv[optind][0] != '-' || argv[optind][1] == '\0')
440 || argv[optind][0] != '+' || argv[optind][1] == '\0')
441 #endif /* GETOPT_COMPAT */
444 if (ordering == REQUIRE_ORDER)
446 optarg = argv[optind++];
450 /* We have found another option-ARGV-element.
451 Start decoding its characters. */
453 nextchar = (argv[optind] + 1
454 + (longopts != NULL && argv[optind][1] == '-'));
458 && ((argv[optind][0] == '-'
459 && (argv[optind][1] == '-' || long_only))
461 || argv[optind][0] == '+'
462 #endif /* GETOPT_COMPAT */
465 const struct option *p;
469 const struct option *pfound = NULL;
472 while (*s && *s != '=')
475 /* Test all options for either exact match or abbreviated matches. */
476 for (p = longopts, option_index = 0; p->name;
478 if (!strncmp (p->name, nextchar, s - nextchar))
480 if (s - nextchar == strlen (p->name))
482 /* Exact match found. */
484 indfound = option_index;
488 else if (pfound == NULL)
490 /* First nonexact match found. */
492 indfound = option_index;
495 /* Second nonexact match found. */
502 fprintf (stderr, "%s: option `%s' is ambiguous\n",
503 argv[0], argv[optind]);
504 nextchar += strlen (nextchar);
511 option_index = indfound;
515 /* Don't test has_arg with >, because some C compilers don't
516 allow it to be used on enums. */
523 if (argv[optind - 1][1] == '-')
526 "%s: option `--%s' doesn't allow an argument\n",
527 argv[0], pfound->name);
529 /* +option or -option */
531 "%s: option `%c%s' doesn't allow an argument\n",
532 argv[0], argv[optind - 1][0], pfound->name);
534 nextchar += strlen (nextchar);
538 else if (pfound->has_arg == 1)
541 optarg = argv[optind++];
545 fprintf (stderr, "%s: option `%s' requires an argument\n",
546 argv[0], argv[optind - 1]);
547 nextchar += strlen (nextchar);
548 return optstring[0] == ':' ? ':' : '?';
551 nextchar += strlen (nextchar);
553 *longind = option_index;
556 *(pfound->flag) = pfound->val;
561 /* Can't find it as a long option. If this is not getopt_long_only,
562 or the option starts with '--' or is not a valid short
563 option, then it's an error.
564 Otherwise interpret it as a short option. */
565 if (!long_only || argv[optind][1] == '-'
567 || argv[optind][0] == '+'
568 #endif /* GETOPT_COMPAT */
569 || my_index (optstring, *nextchar) == NULL)
573 if (argv[optind][1] == '-')
575 fprintf (stderr, "%s: unrecognized option `--%s'\n",
578 /* +option or -option */
579 fprintf (stderr, "%s: unrecognized option `%c%s'\n",
580 argv[0], argv[optind][0], nextchar);
582 nextchar = (char *) "";
588 /* Look at and handle the next option-character. */
591 char c = *nextchar++;
592 char *temp = my_index (optstring, c);
594 /* Increment `optind' when we start to process its last character. */
595 if (*nextchar == '\0')
598 if (temp == NULL || c == ':')
603 if (c < 040 || c >= 0177)
604 fprintf (stderr, "%s: unrecognized option, character code 0%o\n",
607 fprintf (stderr, "%s: unrecognized option `-%c'\n", argv[0], c);
609 /* 1003.2 specifies the format of this message. */
610 fprintf (stderr, "%s: illegal option -- %c\n", argv[0], c);
620 /* This is an option that accepts an argument optionally. */
621 if (*nextchar != '\0')
632 /* This is an option that requires an argument. */
633 if (*nextchar != '\0')
636 /* If we end this ARGV-element by taking the rest as an arg,
637 we must advance to the next element now. */
640 else if (optind == argc)
645 fprintf (stderr, "%s: option `-%c' requires an argument\n",
648 /* 1003.2 specifies the format of this message. */
649 fprintf (stderr, "%s: option requires an argument -- %c\n",
654 if (optstring[0] == ':')
660 /* We already incremented `optind' once;
661 increment it again when taking next ARGV-elt as argument. */
662 optarg = argv[optind++];
671 getopt (argc, argv, optstring)
674 const char *optstring;
676 return _getopt_internal (argc, argv, optstring,
677 (const struct option *) 0,
682 #endif /* _LIBC or not __GNU_LIBRARY__. */
686 /* Compile with -DTEST to make an executable for use in testing
687 the above definition of `getopt'. */
695 int digit_optind = 0;
699 int this_option_optind = optind ? optind : 1;
701 c = getopt (argc, argv, "abc:d:0123456789");
717 if (digit_optind != 0 && digit_optind != this_option_optind)
718 printf ("digits occur in two different argv-elements.\n");
719 digit_optind = this_option_optind;
720 printf ("option %c\n", c);
724 printf ("option a\n");
728 printf ("option b\n");
732 printf ("option c with value `%s'\n", optarg);
739 printf ("?? getopt returned character code 0%o ??\n", c);
745 printf ("non-option ARGV-elements: ");
746 while (optind < argc)
747 printf ("%s ", argv[optind++]);