SystemCall/1/newlibc/other/getopt.c

/* Copyright (C) 1991 Free Software Foundation, Inc.
This file is part of the GNU C Library.

The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Library General Public License as
published by the Free Software Foundation; either version 2 of the
License, or (at your option) any later version.

The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
Library General Public License for more details.

You should have received a copy of the GNU Library General Public
License along with the GNU C Library; see the file COPYING.LIB.  If
not, write to the Free Software Foundation, Inc., 675 Mass Ave,
Cambridge, MA 02139, USA.  */

/* This version of `getopt' appears to the caller like standard POSIX
   `getopt' but it behaves differently for the user, since it allows
   the user to intersperse the options with the other arguments.

   As `getopt' works, it permutes the elements of ARGV so that, when it
   is done, all the options precede everything else.  Thus all application
   programs are extended to handle flexible argument order.

   Setting the environment variable _POSIX_OPTION_ORDER disables permutation.
   Then the behavior is completely standard.

   GNU application programs can use a third alternative mode in which
   they can distinguish the relative order of options and other arguments.  */

#include <ansidecl.h>
#include <stddef.h>
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/* For communication from `getopt' to the caller.
   When `getopt' finds an option that takes an argument,
   the argument value is returned here.
   Also, when `ordering' is RETURN_IN_ORDER,
   each non-option ARGV-element is returned here.  */

char *optarg = NULL;

/* Index in ARGV of the next element to be scanned.
   This is used for communication to and from the caller
   and for communication between successive calls to `getopt'.

   On entry to `getopt', zero means this is the first call; initialize.

   When `getopt' returns -1, this is the index of the first of the
   non-option elements that the caller should itself scan.

   Otherwise, `optind' communicates from one call to the next
   how much of ARGV has been scanned so far.  */

int optind = 1;

static int initialized = 0;

int optopt;

/* The next char to be scanned in the option-element
   in which the last option character we returned was found.
   This allows us to pick up the scan where we left off.

   If this is zero, or a null string, it means resume the scan
   by advancing to the next ARGV-element.  */

static CONST char *nextchar;

/* Callers store zero here to inhibit the
   error message for unrecognized options.  */

int opterr = 1;

/* Describe how to deal with options that follow non-option ARGV-elements.

   UNSPECIFIED means the caller did not specify anything;
   the default is then REQUIRE_ORDER if the environment variable
   _POSIX_OPTION_ORDER is defined, PERMUTE otherwise.

   REQUIRE_ORDER means don't recognize them as options.
   Stop option processing when the first non-option is seen.
   This is what Unix does.

   PERMUTE is the default.  We permute the contents of ARGV as we scan,
   so that eventually all the options are at the end.  This allows options
   to be given in any order, even with programs that were not written to
   expect this.

   RETURN_IN_ORDER is an option available to programs that were written
   to expect options and other ARGV-elements in any order and that care about
   the ordering of the two.  We describe each non-option ARGV-element
   as if it were the argument of an option with character code zero.
   Using `-' as the first character of the list of option characters
   requests this mode of operation.

   The special argument `--' forces an end of option-scanning regardless
   of the value of `ordering'.  In the case of RETURN_IN_ORDER, only
   `--' can cause `getopt' to return -1 with `optind' != ARGC.  */

static enum { REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER } ordering;

/* Handle permutation of arguments.  */

/* Describe the part of ARGV that contains non-options that have
   been skipped.  `first_nonopt' is the index in ARGV of the first of them;
   `last_nonopt' is the index after the last of them.  */

static int first_nonopt;
static int last_nonopt;

/* Exchange two adjacent subsequences of ARGV.
   One subsequence is elements [first_nonopt,last_nonopt)
   which contains all the non-options that have been skipped so far.
   The other is elements [last_nonopt,optind), which contains all
   the options processed since those non-options were skipped.

   `first_nonopt' and `last_nonopt' are relocated so that they describe
   the new indices of the non-options in ARGV after they are moved.  */
static void
DEFUN(exchange, (argv), CONST char **argv)
{
  size_t nonopts_size = (last_nonopt - first_nonopt) * sizeof(char *);
  char **temp = (char **) __alloca(nonopts_size);

  /* Interchange the two blocks of data in ARGV.  */

  memcpy(temp, &argv[first_nonopt], nonopts_size);
  memcpy(&argv[first_nonopt], &argv[last_nonopt], nonopts_size);
  memcpy(&argv[first_nonopt + optind - last_nonopt], temp, nonopts_size);

  /* Update records for the slots the non-options now occupy.  */

  first_nonopt += (optind - last_nonopt);
  last_nonopt = optind;
}


/* Scan elements of ARGV (whose length is ARGC) for
   option characters given in OPTSTRING.

   If an element of ARGV starts with '-', and is not exactly "-" or "--",
   then it is an option element.  The characters of this element
   (aside from the initial '-') are option characters.  If `getopt'
   is called repeatedly, it returns successively each of the option
   characters from each of the option elements.

   If `getopt' finds another option character, it returns that character,
   updating `optind' and `nextchar' so that the next call to `getopt' can
   resume the scan with the following option character or ARGV-element.

   If there are no more option characters, `getopt' returns -1.
   Then `optind' is the index in ARGV of the first ARGV-element
   that is not an option.  (The ARGV-elements have been permuted
   so that those that are not options now come last.)

   OPTSTRING is a string containing the legitimate option characters.
   A colon in OPTSTRING means that the previous character is an option
   that wants an argument.  The argument is taken from the rest of the
   current ARGV-element, or from the following ARGV-element,
   and returned in `optarg'.

   If an option character is seen that is not listed in OPTSTRING,
   return '?' after printing an error message and setting `optopt'
   to the option character.  If you set `opterr' to zero, the error
   message is suppressed but we still set `optopt' and return '?'.

   If a character in OPTSTRING is followed by a colon, that means
   it wants an argument, so the following text inthe same
   ARGV-element, or the text of the following ARGV-element, is
   returned in `optarg'.  Two colons mean an option that wants an
   optional argument; if there is text in the current ARGV-element,
   it is returned in `optarg'.

   If OPTSTRING starts with `-', it requests a different method of handling the
   non-option ARGV-elements.  See the comments about RETURN_IN_ORDER, above.
 */

int
DEFUN(getopt, (argc, argv, optstring),
      int argc AND CONST char **argv AND CONST char *optstring)
{
  /* Initialize the internal data when the first call is made.
     Start processing options with ARGV-element 1
     (since ARGV-element 0 is the program name);
     the sequence of previously skipped non-option
     ARGV-elements is empty.  */

  if (!initialized)
    {
      first_nonopt = last_nonopt = optind = 1;
      initialized = 1;

      nextchar = NULL;

      if (optstring[0] == ':')
	{
	  ++optstring;
	  opterr = 0;
	}

      /* Determine how to handle the ordering of options and nonoptions.  */
      if (optstring[0] == '-')
	ordering = RETURN_IN_ORDER;
      else if (getenv("_POSIX_OPTION_ORDER") != NULL)
	ordering = REQUIRE_ORDER;
      else
	ordering = PERMUTE;

      if (optstring[0] == ':')
	{
	  ++optstring;
	  opterr = 0;
	}
    }

  if (nextchar == NULL || *nextchar == '\0')
    {
      if (ordering == PERMUTE)
	{
	  /* If we have just processed some options
	     following some non-options, exchange them
	     so that the options come first.  */

	  if (first_nonopt != last_nonopt && last_nonopt != optind)
	    exchange(argv);
	  else if (last_nonopt != optind)
	    first_nonopt = optind;

	  /* Now skip any additional non-options and extend
	     the range of non-options previously skipped.  */

	  while (optind < argc &&
		 (argv[optind][0] != '-' || argv[optind][1] == '\0'))
	    ++optind;
	  last_nonopt = optind;
	}

      /* Special ARGV-element `--' means premature end of options.
	 Skip it like a null option, then exchange with previous
	 non-options as if it were an option, then skip everything
	 else like a non-option.  */

      if (optind != argc && !strcmp(argv[optind], "--"))
	{
	  ++optind;

	  if (first_nonopt != last_nonopt && last_nonopt != optind)
	    exchange(argv);
	  else if (first_nonopt == last_nonopt)
	    first_nonopt = optind;
	  last_nonopt = argc;

	  optind = argc;
	}

      /* If we have done all the ARGV-elements,
	 stop the scan and back over any non-options
	 that we skipped and permuted.  */

      if (optind == argc)
	{
	  /* Set the next-arg-index to point at the
	     non-options that we previously skipped,
	     so the caller will digest them.  */
	  if (first_nonopt != last_nonopt)
	    optind = first_nonopt;
	  return -1;
	}

      /* If we have come to a non-option and did
	 not permute it, either stop the scan or
	 describe it to the caller and pass it by.  */

      if (argv[optind][0] != '-' || argv[optind][1] == 0)
	if (ordering == REQUIRE_ORDER)
	  return -1;
	else
	  {
	    optarg = (char *) argv[optind++];
	    return 0;
	  }

      /* We have found another option-ARGV-element.
	 Start decoding its characters.  */

      nextchar = argv[optind] + 1;
    }

  /* Look at and handle the next option-character.  */

  {
    char c = *nextchar++;
    char *temp = strchr(optstring, c);
		
    /* Increment `optind' when we start to process its last character.  */
    if (*nextchar == '\0')
      ++optind;

    if (temp == NULL)
      {
	if (opterr)
	  {
	    if (!isprint(c))
	      fprintf(stderr,
		      "%s: unrecognized option, character code %#.3o octal\n",
		      argv[0], (unsigned int) c);
	    else
	      fprintf(stderr, "%s: unrecognized option `-%c'\n",
		      argv[0], c);
	  }
	optopt = c;
	return '?';
      }
    if (temp[1] == ':')
      {
	if (temp[2] == ':')
	  {
	    /* This is an option that accepts an optional argument.  */
	    if (*nextchar != '\0')
	      optarg = (char *) nextchar;
	    else
	      optarg = NULL;
	    nextchar = NULL;
	  }
	else
	  {
	    /* This is an option that requires an argument.  */
	    if (*nextchar != '\0')
	      {
		optarg = (char *) nextchar;
		/* If we end this ARGV-element by taking the rest as an
		   argument, we must advance to the next element now.  */
		++optind;
		nextchar = NULL;
	      }
	    else if (optind == argc)
	      {
		if (opterr)
		  {
		    if (isprint(c))
		      fprintf(stderr, "%s: no argument for `-%c' option\n",
			      argv[0], c);
		    else
		      fprintf(stderr,
			      "%s: no argument for option %#.3o octal\n",
			      argv[0], (unsigned int) c);
		  }
		optopt = c;
		optarg = NULL;
		return '?';
	      }
	    else
	      /* We already incremented `optind' once; increment it again
		 when taking the next ARGV-element as an argument.  */
	      optarg = (char *) argv[optind++];
	  }
      }
    return c;
  }
}

#ifdef TEST

/* Compile with -DTEST to make an executable for use
   in testing the above definition of `getopt'.  */

int
DEFUN(main, (argc, argv), int argc AND char **argv)
{
  register int c;
  int digit_optind = 0;

  for (;;)
    {
      int this_option_optind = optind;
      if ((c = getopt(argc, argv, "abc:d:0123456789")) == -1)
	break;
      else
	switch (c)
	  {
	  case '0':
	  case '1':
	  case '2':
	  case '3':
	  case '4':
	  case '5':
	  case '6':
	  case '7':
	  case '8':
	  case '9':
	    if (digit_optind > 0 && digit_optind != this_option_optind)
	      puts("digits occur in two different ARGV-elements.");
	    digit_optind = this_option_optind;
	    printf("option %c\n", c);
	    break;
	  case 'a':
	    puts("option a");
	    break;
	  case 'b':
	    puts("option b");
	    break;
	  case 'c':
	    printf("option c with value `%s'\n", optarg);
	    break;
	  case '?':
	    break;
	  default:
	    printf("?? getopt returned character code %#.3o ??\n", c);
	    break;
	  }
    }

  if (optind < argc)
    {
      fputs("non-option ARGV-elements: ", stdout);
      while (optind < argc)
	printf("%s ", argv[optind++]);
      putchar('\n');
    }

  exit(0);
  return 0;
}

#endif /* TEST */