1/* Getopt for GNU.
2   NOTE: getopt is now part of the C library, so if you don't know what
3   "Keep this file name-space clean" means, talk to roland@gnu.ai.mit.edu
4   before changing it!
5
6   Copyright (C) 1987, 88, 89, 90, 91, 92, 93, 94
7   	Free Software Foundation, Inc.
8
9This file is part of the GNU C Library.  Its master source is NOT part of
10the C library, however.  The master source lives in /gd/gnu/lib.
11
12The GNU C Library is free software; you can redistribute it and/or
13modify it under the terms of the GNU Library General Public License as
14published by the Free Software Foundation; either version 2 of the
15License, or (at your option) any later version.
16
17The GNU C Library is distributed in the hope that it will be useful,
18but WITHOUT ANY WARRANTY; without even the implied warranty of
19MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20Library General Public License for more details.
21
22You should have received a copy of the GNU Library General Public
23License along with the GNU C Library; see the file COPYING.LIB.  If
24not, write to the Free Software Foundation, Inc., 675 Mass Ave,
25Cambridge, MA 02139, USA.  */
26
27/* This tells Alpha OSF/1 not to define a getopt prototype in <stdio.h>.
28   Ditto for AIX 3.2 and <stdlib.h>.  */
29#ifndef _NO_PROTO
30#define _NO_PROTO
31#endif
32
33#ifdef HAVE_CONFIG_H
34#include <config.h>
35#endif
36
37#if !defined (__STDC__) || !__STDC__
38/* This is a separate conditional since some stdc systems
39   reject `defined (const)'.  */
40#ifndef const
41#define const
42#endif
43#endif
44
45#include <stdio.h>
46
47/* Comment out all this code if we are using the GNU C Library, and are not
48   actually compiling the library itself.  This code is part of the GNU C
49   Library, but also included in many other GNU distributions.  Compiling
50   and linking in this code is a waste when using the GNU C library
51   (especially if it is a shared library).  Rather than having every GNU
52   program understand `configure --with-gnu-libc' and omit the object files,
53   it is simpler to just do this in the source for each such file.  */
54
55#if defined (_LIBC) || !defined (__GNU_LIBRARY__)
56
57
58/* This needs to come after some library #include
59   to get __GNU_LIBRARY__ defined.  */
60#ifdef	__GNU_LIBRARY__
61/* Don't include stdlib.h for non-GNU C libraries because some of them
62   contain conflicting prototypes for getopt.  */
63#include <stdlib.h>
64#endif	/* GNU C library.  */
65
66/* This version of `getopt' appears to the caller like standard Unix `getopt'
67   but it behaves differently for the user, since it allows the user
68   to intersperse the options with the other arguments.
69
70   As `getopt' works, it permutes the elements of ARGV so that,
71   when it is done, all the options precede everything else.  Thus
72   all application programs are extended to handle flexible argument order.
73
74   Setting the environment variable POSIXLY_CORRECT disables permutation.
75   Then the behavior is completely standard.
76
77   GNU application programs can use a third alternative mode in which
78   they can distinguish the relative order of options and other arguments.  */
79
80#include "getopt.h"
81
82/* For communication from `getopt' to the caller.
83   When `getopt' finds an option that takes an argument,
84   the argument value is returned here.
85   Also, when `ordering' is RETURN_IN_ORDER,
86   each non-option ARGV-element is returned here.  */
87
88char *optarg = NULL;
89
90/* Index in ARGV of the next element to be scanned.
91   This is used for communication to and from the caller
92   and for communication between successive calls to `getopt'.
93
94   On entry to `getopt', zero means this is the first call; initialize.
95
96   When `getopt' returns EOF, this is the index of the first of the
97   non-option elements that the caller should itself scan.
98
99   Otherwise, `optind' communicates from one call to the next
100   how much of ARGV has been scanned so far.  */
101
102/* XXX 1003.2 says this must be 1 before any call.  */
103int optind = 0;
104
105/* The next char to be scanned in the option-element
106   in which the last option character we returned was found.
107   This allows us to pick up the scan where we left off.
108
109   If this is zero, or a null string, it means resume the scan
110   by advancing to the next ARGV-element.  */
111
112static char *nextchar;
113
114/* Callers store zero here to inhibit the error message
115   for unrecognized options.  */
116
117int opterr = 1;
118
119/* Set to an option character which was unrecognized.
120   This must be initialized on some systems to avoid linking in the
121   system's own getopt implementation.  */
122
123int optopt = '?';
124
125/* Describe how to deal with options that follow non-option ARGV-elements.
126
127   If the caller did not specify anything,
128   the default is REQUIRE_ORDER if the environment variable
129   POSIXLY_CORRECT is defined, PERMUTE otherwise.
130
131   REQUIRE_ORDER means don't recognize them as options;
132   stop option processing when the first non-option is seen.
133   This is what Unix does.
134   This mode of operation is selected by either setting the environment
135   variable POSIXLY_CORRECT, or using `+' as the first character
136   of the list of option characters.
137
138   PERMUTE is the default.  We permute the contents of ARGV as we scan,
139   so that eventually all the non-options are at the end.  This allows options
140   to be given in any order, even with programs that were not written to
141   expect this.
142
143   RETURN_IN_ORDER is an option available to programs that were written
144   to expect options and other ARGV-elements in any order and that care about
145   the ordering of the two.  We describe each non-option ARGV-element
146   as if it were the argument of an option with character code 1.
147   Using `-' as the first character of the list of option characters
148   selects this mode of operation.
149
150   The special argument `--' forces an end of option-scanning regardless
151   of the value of `ordering'.  In the case of RETURN_IN_ORDER, only
152   `--' can cause `getopt' to return EOF with `optind' != ARGC.  */
153
154static enum
155{
156  REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
157} ordering;
158
159/* Value of POSIXLY_CORRECT environment variable.  */
160static char *posixly_correct;
161
162#ifdef	__GNU_LIBRARY__
163/* We want to avoid inclusion of string.h with non-GNU libraries
164   because there are many ways it can cause trouble.
165   On some systems, it contains special magic macros that don't work
166   in GCC.  */
167#include <string.h>
168#define	my_index	strchr
169#else
170
171/* Avoid depending on library functions or files
172   whose names are inconsistent.  */
173
174char *getenv ();
175
176static char *
177my_index (str, chr)
178     const char *str;
179     int chr;
180{
181  while (*str)
182    {
183      if (*str == chr)
184	return (char *) str;
185      str++;
186    }
187  return 0;
188}
189
190/* If using GCC, we can safely declare strlen this way.
191   If not using GCC, it is ok not to declare it.  */
192#ifdef __GNUC__
193/* Note that Motorola Delta 68k R3V7 comes with GCC but not stddef.h.
194   That was relevant to code that was here before.  */
195#if !defined (__STDC__) || !__STDC__
196/* gcc with -traditional declares the built-in strlen to return int,
197   and has done so at least since version 2.4.5. -- rms.  */
198extern int strlen (const char *);
199#endif /* not __STDC__ */
200#endif /* __GNUC__ */
201
202#endif /* not __GNU_LIBRARY__ */
203
204/* Handle permutation of arguments.  */
205
206/* Describe the part of ARGV that contains non-options that have
207   been skipped.  `first_nonopt' is the index in ARGV of the first of them;
208   `last_nonopt' is the index after the last of them.  */
209
210static int first_nonopt;
211static int last_nonopt;
212
213/* Exchange two adjacent subsequences of ARGV.
214   One subsequence is elements [first_nonopt,last_nonopt)
215   which contains all the non-options that have been skipped so far.
216   The other is elements [last_nonopt,optind), which contains all
217   the options processed since those non-options were skipped.
218
219   `first_nonopt' and `last_nonopt' are relocated so that they describe
220   the new indices of the non-options in ARGV after they are moved.  */
221
222static void
223exchange (argv)
224     char **argv;
225{
226  int bottom = first_nonopt;
227  int middle = last_nonopt;
228  int top = optind;
229  char *tem;
230
231  /* Exchange the shorter segment with the far end of the longer segment.
232     That puts the shorter segment into the right place.
233     It leaves the longer segment in the right place overall,
234     but it consists of two parts that need to be swapped next.  */
235
236  while (top > middle && middle > bottom)
237    {
238      if (top - middle > middle - bottom)
239	{
240	  /* Bottom segment is the short one.  */
241	  int len = middle - bottom;
242	  register int i;
243
244	  /* Swap it with the top part of the top segment.  */
245	  for (i = 0; i < len; i++)
246	    {
247	      tem = argv[bottom + i];
248	      argv[bottom + i] = argv[top - (middle - bottom) + i];
249	      argv[top - (middle - bottom) + i] = tem;
250	    }
251	  /* Exclude the moved bottom segment from further swapping.  */
252	  top -= len;
253	}
254      else
255	{
256	  /* Top segment is the short one.  */
257	  int len = top - middle;
258	  register int i;
259
260	  /* Swap it with the bottom part of the bottom segment.  */
261	  for (i = 0; i < len; i++)
262	    {
263	      tem = argv[bottom + i];
264	      argv[bottom + i] = argv[middle + i];
265	      argv[middle + i] = tem;
266	    }
267	  /* Exclude the moved top segment from further swapping.  */
268	  bottom += len;
269	}
270    }
271
272  /* Update records for the slots the non-options now occupy.  */
273
274  first_nonopt += (optind - last_nonopt);
275  last_nonopt = optind;
276}
277
278/* Initialize the internal data when the first call is made.  */
279
280static const char *
281_getopt_initialize (optstring)
282     const char *optstring;
283{
284  /* Start processing options with ARGV-element 1 (since ARGV-element 0
285     is the program name); the sequence of previously skipped
286     non-option ARGV-elements is empty.  */
287
288  first_nonopt = last_nonopt = optind = 1;
289
290  nextchar = NULL;
291
292  posixly_correct = getenv ("POSIXLY_CORRECT");
293
294  /* Determine how to handle the ordering of options and nonoptions.  */
295
296  if (optstring[0] == '-')
297    {
298      ordering = RETURN_IN_ORDER;
299      ++optstring;
300    }
301  else if (optstring[0] == '+')
302    {
303      ordering = REQUIRE_ORDER;
304      ++optstring;
305    }
306  else if (posixly_correct != NULL)
307    ordering = REQUIRE_ORDER;
308  else
309    ordering = PERMUTE;
310
311  return optstring;
312}
313
314/* Scan elements of ARGV (whose length is ARGC) for option characters
315   given in OPTSTRING.
316
317   If an element of ARGV starts with '-', and is not exactly "-" or "--",
318   then it is an option element.  The characters of this element
319   (aside from the initial '-') are option characters.  If `getopt'
320   is called repeatedly, it returns successively each of the option characters
321   from each of the option elements.
322
323   If `getopt' finds another option character, it returns that character,
324   updating `optind' and `nextchar' so that the next call to `getopt' can
325   resume the scan with the following option character or ARGV-element.
326
327   If there are no more option characters, `getopt' returns `EOF'.
328   Then `optind' is the index in ARGV of the first ARGV-element
329   that is not an option.  (The ARGV-elements have been permuted
330   so that those that are not options now come last.)
331
332   OPTSTRING is a string containing the legitimate option characters.
333   If an option character is seen that is not listed in OPTSTRING,
334   return '?' after printing an error message.  If you set `opterr' to
335   zero, the error message is suppressed but we still return '?'.
336
337   If a char in OPTSTRING is followed by a colon, that means it wants an arg,
338   so the following text in the same ARGV-element, or the text of the following
339   ARGV-element, is returned in `optarg'.  Two colons mean an option that
340   wants an optional arg; if there is text in the current ARGV-element,
341   it is returned in `optarg', otherwise `optarg' is set to zero.
342
343   If OPTSTRING starts with `-' or `+', it requests different methods of
344   handling the non-option ARGV-elements.
345   See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.
346
347   Long-named options begin with `--' instead of `-'.
348   Their names may be abbreviated as long as the abbreviation is unique
349   or is an exact match for some defined option.  If they have an
350   argument, it follows the option name in the same ARGV-element, separated
351   from the option name by a `=', or else the in next ARGV-element.
352   When `getopt' finds a long-named option, it returns 0 if that option's
353   `flag' field is nonzero, the value of the option's `val' field
354   if the `flag' field is zero.
355
356   The elements of ARGV aren't really const, because we permute them.
357   But we pretend they're const in the prototype to be compatible
358   with other systems.
359
360   LONGOPTS is a vector of `struct option' terminated by an
361   element containing a name which is zero.
362
363   LONGIND returns the index in LONGOPT of the long-named option found.
364   It is only valid when a long-named option has been found by the most
365   recent call.
366
367   If LONG_ONLY is nonzero, '-' as well as '--' can introduce
368   long-named options.  */
369
370int
371_getopt_internal (argc, argv, optstring, longopts, longind, long_only)
372     int argc;
373     char *const *argv;
374     const char *optstring;
375     const struct option *longopts;
376     int *longind;
377     int long_only;
378{
379  optarg = NULL;
380
381  if (optind == 0)
382    optstring = _getopt_initialize (optstring);
383
384  if (nextchar == NULL || *nextchar == '\0')
385    {
386      /* Advance to the next ARGV-element.  */
387
388      if (ordering == PERMUTE)
389	{
390	  /* If we have just processed some options following some non-options,
391	     exchange them so that the options come first.  */
392
393	  if (first_nonopt != last_nonopt && last_nonopt != optind)
394	    exchange ((char **) argv);
395	  else if (last_nonopt != optind)
396	    first_nonopt = optind;
397
398	  /* Skip any additional non-options
399	     and extend the range of non-options previously skipped.  */
400
401	  while (optind < argc
402		 && (argv[optind][0] != '-' || argv[optind][1] == '\0'))
403	    optind++;
404	  last_nonopt = optind;
405	}
406
407      /* The special ARGV-element `--' means premature end of options.
408	 Skip it like a null option,
409	 then exchange with previous non-options as if it were an option,
410	 then skip everything else like a non-option.  */
411
412      if (optind != argc && !strcmp (argv[optind], "--"))
413	{
414	  optind++;
415
416	  if (first_nonopt != last_nonopt && last_nonopt != optind)
417	    exchange ((char **) argv);
418	  else if (first_nonopt == last_nonopt)
419	    first_nonopt = optind;
420	  last_nonopt = argc;
421
422	  optind = argc;
423	}
424
425      /* If we have done all the ARGV-elements, stop the scan
426	 and back over any non-options that we skipped and permuted.  */
427
428      if (optind == argc)
429	{
430	  /* Set the next-arg-index to point at the non-options
431	     that we previously skipped, so the caller will digest them.  */
432	  if (first_nonopt != last_nonopt)
433	    optind = first_nonopt;
434	  return EOF;
435	}
436
437      /* If we have come to a non-option and did not permute it,
438	 either stop the scan or describe it to the caller and pass it by.  */
439
440      if ((argv[optind][0] != '-' || argv[optind][1] == '\0'))
441	{
442	  if (ordering == REQUIRE_ORDER)
443	    return EOF;
444	  optarg = argv[optind++];
445	  return 1;
446	}
447
448      /* We have found another option-ARGV-element.
449	 Skip the initial punctuation.  */
450
451      nextchar = (argv[optind] + 1
452		  + (longopts != NULL && argv[optind][1] == '-'));
453    }
454
455  /* Decode the current option-ARGV-element.  */
456
457  /* Check whether the ARGV-element is a long option.
458
459     If long_only and the ARGV-element has the form "-f", where f is
460     a valid short option, don't consider it an abbreviated form of
461     a long option that starts with f.  Otherwise there would be no
462     way to give the -f short option.
463
464     On the other hand, if there's a long option "fubar" and
465     the ARGV-element is "-fu", do consider that an abbreviation of
466     the long option, just like "--fu", and not "-f" with arg "u".
467
468     This distinction seems to be the most useful approach.  */
469
470  if (longopts != NULL
471      && (argv[optind][1] == '-'
472	  || (long_only && (argv[optind][2] || !my_index (optstring, argv[optind][1])))))
473    {
474      char *nameend;
475      const struct option *p;
476      const struct option *pfound = NULL;
477      int exact = 0;
478      int ambig = 0;
479      int indfound;
480      int option_index;
481
482      for (nameend = nextchar; *nameend && *nameend != '='; nameend++)
483	/* Do nothing.  */ ;
484
485      /* Test all long options for either exact match
486	 or abbreviated matches.  */
487      for (p = longopts, option_index = 0; p->name; p++, option_index++)
488	if (!strncmp (p->name, nextchar, nameend - nextchar))
489	  {
490	    if (nameend - nextchar == strlen (p->name))
491	      {
492		/* Exact match found.  */
493		pfound = p;
494		indfound = option_index;
495		exact = 1;
496		break;
497	      }
498	    else if (pfound == NULL)
499	      {
500		/* First nonexact match found.  */
501		pfound = p;
502		indfound = option_index;
503	      }
504	    else
505	      /* Second or later nonexact match found.  */
506	      ambig = 1;
507	  }
508
509      if (ambig && !exact)
510	{
511	  if (opterr)
512	    fprintf (stderr, "%s: option `%s' is ambiguous\n",
513		     argv[0], argv[optind]);
514	  nextchar += strlen (nextchar);
515	  optind++;
516	  return '?';
517	}
518
519      if (pfound != NULL)
520	{
521	  option_index = indfound;
522	  optind++;
523	  if (*nameend)
524	    {
525	      /* Don't test has_arg with >, because some C compilers don't
526		 allow it to be used on enums.  */
527	      if (pfound->has_arg)
528		optarg = nameend + 1;
529	      else
530		{
531		  if (opterr)
532		    {
533		      if (argv[optind - 1][1] == '-')
534			/* --option */
535			fprintf (stderr,
536				 "%s: option `--%s' doesn't allow an argument\n",
537				 argv[0], pfound->name);
538		      else
539			/* +option or -option */
540			fprintf (stderr,
541			     "%s: option `%c%s' doesn't allow an argument\n",
542			     argv[0], argv[optind - 1][0], pfound->name);
543		    }
544		  nextchar += strlen (nextchar);
545		  return '?';
546		}
547	    }
548	  else if (pfound->has_arg == 1)
549	    {
550	      if (optind < argc)
551		optarg = argv[optind++];
552	      else
553		{
554		  if (opterr)
555		    fprintf (stderr, "%s: option `%s' requires an argument\n",
556			     argv[0], argv[optind - 1]);
557		  nextchar += strlen (nextchar);
558		  return optstring[0] == ':' ? ':' : '?';
559		}
560	    }
561	  nextchar += strlen (nextchar);
562	  if (longind != NULL)
563	    *longind = option_index;
564	  if (pfound->flag)
565	    {
566	      *(pfound->flag) = pfound->val;
567	      return 0;
568	    }
569	  return pfound->val;
570	}
571
572      /* Can't find it as a long option.  If this is not getopt_long_only,
573	 or the option starts with '--' or is not a valid short
574	 option, then it's an error.
575	 Otherwise interpret it as a short option.  */
576      if (!long_only || argv[optind][1] == '-'
577	  || my_index (optstring, *nextchar) == NULL)
578	{
579	  if (opterr)
580	    {
581	      if (argv[optind][1] == '-')
582		/* --option */
583		fprintf (stderr, "%s: unrecognized option `--%s'\n",
584			 argv[0], nextchar);
585	      else
586		/* +option or -option */
587		fprintf (stderr, "%s: unrecognized option `%c%s'\n",
588			 argv[0], argv[optind][0], nextchar);
589	    }
590	  nextchar = (char *) "";
591	  optind++;
592	  return '?';
593	}
594    }
595
596  /* Look at and handle the next short option-character.  */
597
598  {
599    char c = *nextchar++;
600    char *temp = my_index (optstring, c);
601
602    /* Increment `optind' when we start to process its last character.  */
603    if (*nextchar == '\0')
604      ++optind;
605
606    if (temp == NULL || c == ':')
607      {
608	if (opterr)
609	  {
610	    if (posixly_correct)
611	      /* 1003.2 specifies the format of this message.  */
612	      fprintf (stderr, "%s: illegal option -- %c\n", argv[0], c);
613	    else
614	      fprintf (stderr, "%s: invalid option -- %c\n", argv[0], c);
615	  }
616	optopt = c;
617	return '?';
618      }
619    if (temp[1] == ':')
620      {
621	if (temp[2] == ':')
622	  {
623	    /* This is an option that accepts an argument optionally.  */
624	    if (*nextchar != '\0')
625	      {
626		optarg = nextchar;
627		optind++;
628	      }
629	    else
630	      optarg = NULL;
631	    nextchar = NULL;
632	  }
633	else
634	  {
635	    /* This is an option that requires an argument.  */
636	    if (*nextchar != '\0')
637	      {
638		optarg = nextchar;
639		/* If we end this ARGV-element by taking the rest as an arg,
640		   we must advance to the next element now.  */
641		optind++;
642	      }
643	    else if (optind == argc)
644	      {
645		if (opterr)
646		  {
647		    /* 1003.2 specifies the format of this message.  */
648		    fprintf (stderr, "%s: option requires an argument -- %c\n",
649			     argv[0], c);
650		  }
651		optopt = c;
652		if (optstring[0] == ':')
653		  c = ':';
654		else
655		  c = '?';
656	      }
657	    else
658	      /* We already incremented `optind' once;
659		 increment it again when taking next ARGV-elt as argument.  */
660	      optarg = argv[optind++];
661	    nextchar = NULL;
662	  }
663      }
664    return c;
665  }
666}
667
668int
669getopt (argc, argv, optstring)
670     int argc;
671     char *const *argv;
672     const char *optstring;
673{
674  return _getopt_internal (argc, argv, optstring,
675			   (const struct option *) 0,
676			   (int *) 0,
677			   0);
678}
679
680#endif	/* _LIBC or not __GNU_LIBRARY__.  */
681
682#ifdef TEST
683
684/* Compile with -DTEST to make an executable for use in testing
685   the above definition of `getopt'.  */
686
687int
688main (argc, argv)
689     int argc;
690     char **argv;
691{
692  int c;
693  int digit_optind = 0;
694
695  while (1)
696    {
697      int this_option_optind = optind ? optind : 1;
698
699      c = getopt (argc, argv, "abc:d:0123456789");
700      if (c == EOF)
701	break;
702
703      switch (c)
704	{
705	case '0':
706	case '1':
707	case '2':
708	case '3':
709	case '4':
710	case '5':
711	case '6':
712	case '7':
713	case '8':
714	case '9':
715	  if (digit_optind != 0 && digit_optind != this_option_optind)
716	    printf ("digits occur in two different argv-elements.\n");
717	  digit_optind = this_option_optind;
718	  printf ("option %c\n", c);
719	  break;
720
721	case 'a':
722	  printf ("option a\n");
723	  break;
724
725	case 'b':
726	  printf ("option b\n");
727	  break;
728
729	case 'c':
730	  printf ("option c with value `%s'\n", optarg);
731	  break;
732
733	case '?':
734	  break;
735
736	default:
737	  printf ("?? getopt returned character code 0%o ??\n", c);
738	}
739    }
740
741  if (optind < argc)
742    {
743      printf ("non-option ARGV-elements: ");
744      while (optind < argc)
745	printf ("%s ", argv[optind++]);
746      printf ("\n");
747    }
748
749  exit (0);
750}
751
752#endif /* TEST */
753