/* Ultra-Getopt - A replacement for getopt() with support for many common
 *		  extensions, MS-DOS formatted option strings, and much more.
 *
 * To use this library as a replacement for vendor-provided getopt() functions,
 * define ULTRAGETOPT_REPLACE_GETOPT and include "ultragetopt.h" after the
 * vendor-provided headers for getopt() functions.
 *
 * Copyright (C) 2007-2011, Kevin Locke <kevin@kevinlocke.name>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 */

#include <assert.h>
#include <ctype.h>	/* islower() isupper() tolower() toupper() */
#include <stdarg.h>
#include <stdio.h>	/* fprintf() */
#include <stdlib.h>	/* getenv() */
#include <string.h>	/* strcmp(), strncmp(), strchr() */

#if HAVE_STRINGS_H
# include <strings.h>	/* strcasecmp(), strncasecmp() */
#endif

#undef ULTRAGETOPT_REPLACE_GETOPT   /* Protect against project-wide defines */
#include "ultragetopt.h"

/* Define replacements for missing functions */
#if !HAVE_STRCASECMP && HAVE__STRICMP
# define strcasecmp _stricmp
#endif

#if !HAVE_STRNCASECMP && HAVE__STRNICMP
# define strncasecmp _strnicmp
#endif

#if !HAVE_STRCHR && HAVE_INDEX
# define strchr index
#endif

/* Supported defines:
 * ULTRAGETOPT_LIKE_BSD		Behave like BSD getopt()
 * ULTRAGETOPT_LIKE_DARWIN	Behave like Darwin (Mac OS) getopt()
 * ULTRAGETOPT_LIKE_GNU		Behave like GNU getopt()
 * ULTRAGETOPT_LIKE_POSIX   	Behave like POSIX definition of getopt()
 *
 * ULTRAGETOPT_ASSIGNSPACE	Parse "-o value" as "value" rather than " value"
 *				Note: Only applicable when argv[x] == "-o value"
 *				      Not for argv[x] == "-o" [x+1] == "value"
 * ULTRAGETOPT_DEFAULTOPTOPT	Set optopt to this value by default on each
 *				call to getopt()
 * ULTRAGETOPT_HYPHENARG	Accept -option -arg as -option with argument
 *				"-arg" rather than -option missing argument
 *				Note:  A single "-" is always accepted as an
 *				argument
 * ULTRAGETOPT_LONGOPTADJACENT	Accept adjacent arguments to long options
 *				(e.g. --optionarg) based on first longest-match
 * ULTRAGETOPT_OPTIONPERMUTE	Permute options, do not stop at first non-option
 *				Behaves like GNU getopt where leading '+' or
 *				$POSIXLY_CORRECT both stop this @ runtime
 * ULTRAGETOPT_SHORTOPTASSIGN	Support -o=file syntax for short options
 * ULTRAGETOPT_SEPARATEDOPTIONAL Accept separated optional arguments
 *				 Parse -o file as -o  with argument file
 * ULTRAGETOPT_DOS_DASH		Support - and -- options in ultragetopt*_dos()
 * ULTRAGETOPT_BSD_ERRORS	Print error messages matching BSD getopt
 * ULTRAGETOPT_DARWIN_ERRORS	Print error messages matching Darwin getopt
 * ULTRAGETOPT_GNU_ERRORS	Print error messages matching GNU getopt
 * ULTRAGETOPT_NO_EATDASHDASH	Do not increment optind when argv[optind] is --
 * ULTRAGETOPT_NO_OPTIONALARG	Do not support GNU "::" optional argument
 *				Always supported in *_long*()
 * ULTRAGETOPT_NO_OPTIONASSIGN	Do not support --option=value syntax
 */

#ifdef ULTRAGETOPT_LIKE_POSIX
# define ULTRAGETOPT_NO_OPTIONALARG
# define ULTRAGETOPT_NO_OPTIONASSIGN
# undef ULTRAGETOPT_NO_EATDASHDASH
# undef ULTRAGETOPT_ASSIGNSPACE
# undef ULTRAGETOPT_BSD_ERRORS
# undef ULTRAGETOPT_DARWIN_ERRORS
# undef ULTRAGETOPT_GNU_ERRORS
# undef ULTRAGETOPT_OPTIONPERMUTE
# undef ULTRAGETOPT_SHORTOPTASSIGN
#elif defined(ULTRAGETOPT_LIKE_GNU)
# define ULTRAGETOPT_GNU_ERRORS
# define ULTRAGETOPT_HYPHENARG
# define ULTRAGETOPT_OPTIONPERMUTE
# undef ULTRAGETOPT_ASSIGNSPACE
# undef ULTRAGETOPT_NO_OPTIONALARG
# undef ULTRAGETOPT_NO_OPTIONASSIGN
# undef ULTRAGETOPT_NO_EATDASHDASH
# undef ULTRAGETOPT_SHORTOPTASSIGN
# undef ULTRAGETOPT_SEPARATEOPTIONAL
# undef ULTRAGETOPT_LONGOPTADJACENT
#elif defined(ULTRAGETOPT_LIKE_BSD)
# define ULTRAGETOPT_BSD_ERRORS
# define ULTRAGETOPT_OPTIONPERMUTE
# define ULTRAGETOPT_DEFAULTOPTOPT '?'
# undef ULTRAGETOPT_ASSIGNSPACE
# undef ULTRAGETOPT_NO_OPTIONALARG
# undef ULTRAGETOPT_NO_OPTIONASSIGN
# undef ULTRAGETOPT_NO_EATDASHDASH
# undef ULTRAGETOPT_SHORTOPTASSIGN
# undef ULTRAGETOPT_SEPARATEOPTIONAL
# undef ULTRAGETOPT_LONGOPTADJACENT
#elif defined(ULTRAGETOPT_LIKE_DARWIN)
# define ULTRAGETOPT_DARWIN_ERRORS
# define ULTRAGETOPT_OPTIONPERMUTE
# undef ULTRAGETOPT_ASSIGNSPACE
# undef ULTRAGETOPT_NO_OPTIONALARG
# undef ULTRAGETOPT_NO_OPTIONASSIGN
# undef ULTRAGETOPT_SHORTOPTASSIGN
# undef ULTRAGETOPT_NO_EATDASHDASH
# undef ULTRAGETOPT_SEPARATEOPTIONAL
# undef ULTRAGETOPT_LONGOPTADJACENT
#endif

#ifdef ULTRAGETOPT_NO_OPTIONASSIGN
static const char *const unixassigners = "";
static const char *const dosassigners = ":";
#elif defined(ULTRAGETOPT_OPTIONSPACE)
static const char *const unixassigners = "= ";
static const char *const dosassigners = ":= ";
#else
static const char *const unixassigners = "=";
static const char *const dosassigners = ":=";
#endif

#ifdef ULTRAGETOPT_DOS_DASH
static const char *const unixleaders = "-";
static const char *const dosleaders = "/-";
#else
static const char *const unixleaders = "-";
static const char *const dosleaders = "/";
#endif

/* Flags for all variants of ultragetopt*() */
static const int getoptflags = 0
#ifdef ULTRAGETOPT_SEPARATEDOPTIONAL
			       | UGO_SEPARATEDOPTIONAL
#endif
#ifdef ULTRAGETOPT_SHORTOPTASSIGN
			       | UGO_SHORTOPTASSIGN
#endif
#ifdef ULTRAGETOPT_NO_EATDASHDASH
			       | UGO_NOEATDASHDASH
#endif
#ifdef ULTRAGETOPT_HYPHENARG
			       | UGO_HYPHENARG
#endif
			       ;

#ifdef ULTRAGETOPT_GNU_ERRORS
static const char *const errorarg =
    "%s: option `%.*s' doesn't allow an argument\n";
static const char *const errornoarg =
    "%s: option `%.*s' requires an argument \n";
static const char *const erroropt = 
    "%s: unrecognized option `%.*s'\n";
static const char *const errorargc =
    "%s: option `-%c' does not take an argument\n";
static const char *const errornoargc =
    "%s: option requires an argument -- `-%c'\n";
static const char *const erroroptc = 
    "%s: invalid option -- %c\n";
#elif defined(ULTRAGETOPT_BSD_ERRORS)
static const char *const errorarg =
    "%s: option doesn't take an argument -- %.*s\n";
static const char *const errornoarg =
    "%s: option requires an argument -- %.*s\n";
static const char *const erroropt = 
    "%s: unknown option -- %.*s\n";
static const char *const errorargc =
    "%s: option doesn't take an argument -- %c\n";
static const char *const errornoargc =
    "%s: option requires an argument -- %c\n";
static const char *const erroroptc = 
    "%s: unknown option -- %c\n";
#elif defined(ULTRAGETOPT_DARWIN_ERRORS)
static const char *const errorarg =
    "%s: option `%.*s' doesn't allow an argument\n"; /* with -- */
static const char *const errornoarg =
    "%s: option `%.*s' requires an argument\n";
static const char *const erroropt = 
    "%s: unrecognized option `%.*s'\n"; /* with -- */
static const char *const errorargc =
    "%s: option doesn't take an argument -- %c\n";
static const char *const errornoargc =
    "%s: option requires an argument -- %c\n";
static const char *const erroroptc = 
    "%s: invalid option -- %c\n";
#else /* POSIX-like */
static const char *const errorarg =
    "%s: option does not take an argument -- %.*s\n";
static const char *const errornoarg =
    "%s: option requires an argument -- %.*s\n";
static const char *const erroropt = 
    "%s: illegal option -- %.*s\n";
static const char *const errorargc =
    "%s: option does not take an argument -- %c\n";
static const char *const errornoargc =
    "%s: option requires an argument -- %c\n";
static const char *const erroroptc = 
    "%s: illegal option -- %c\n";
#endif

/* Globals to match optarg, optind, opterr, optopt, optreset */
char *ultraoptarg = NULL;
int ultraoptind = 1;
int ultraopterr = 1;
int ultraoptreset = 0;
#ifdef ULTRAGETOPT_DEFAULTOPTOPT
int ultraoptopt = ULTRAGETOPT_DEFAULTOPTOPT -0;
#else
int ultraoptopt = 0;
#endif

static int ultraoptnum = 0; /* How many options of the current multi-option
			       argument have been processed?  (e.g. -vvv) */

/* Add format error checking for gcc versions that support it */
#if defined(__GNUC__) && __GNUC__ > 2 || (__GNUC__ == 2 && __GNUC_MINOR > 6)
static void print_error(int flags, const char *template, ...)
    __attribute__ ((format (printf, 2, 3)));
#endif

/* Print errors only if not suppressed */
static void print_error(int flags, const char *template, ...)
{
    va_list ap;

    va_start(ap, template);
    if (ultraopterr != 0 && !(flags & UGO_NOPRINTERR))
	vfprintf(stderr, template, ap);
    va_end(ap);
}

/* Check if an argument string looks like an option string */
static inline int like_option(const char *arg, const char *optleaders)
{
    return arg != NULL &&
	arg[0] != '\0' &&			/* >= 2 characters long */
	arg[1] != '\0' &&
	strchr(optleaders, arg[0]) &&		/* Starts with optleader */
	(arg[2] != '\0' || arg[0] != arg[1]);	/* Not -- */
}

/* Check if an argument string looks like the option terminator string */
static inline int like_optterm(const char *arg, const char *optleaders)
{
    return arg != NULL &&
	arg[0] != '\0' &&
	arg[1] != '\0' &&
	arg[2] == '\0' &&
	arg[0] == arg[1] &&
	strchr(optleaders, arg[0]);
}

/* Check if an argument string looks like an option argument string */
static inline int like_optarg(const char *arg, const char *optleaders,
			      int allow_option)
{
    return arg != NULL &&
	(allow_option ||
	    (!like_option(arg, optleaders) && !like_optterm(arg, optleaders)));
}

/* If argv[curopt] matches a long option, return the index of that option
 * Otherwise, return -1
 * If it has an adjacent argument, return pointer to it in longarg, else NULL
 */
static int match_longopt(int curopt, char *const argv[],
			 const struct option *longopts, const char *assigners,
			 const char *optleaders, int flags, char **longarg)
{
    size_t alen, optnamelen = 0;
    char *optname;
    char *temp;
    int i;
    int (*optncmp)(const char *s1, const char *s2, size_t n);

    if (longarg == NULL)
	longarg = &temp;
    *longarg = NULL;

    if (flags & UGO_CASEINSENSITIVE)
	optncmp = strncasecmp;
    else
	optncmp = strncmp;

    if (longopts == NULL)
	return -1;

    if (!like_option(argv[curopt], optleaders))
	return -1;

    if (flags & UGO_SINGLELEADERONLY) {
	optname = argv[curopt]+1;
    } else if (!strchr(optleaders, argv[curopt][1])) {
	/* Possible short option */
	if (flags & UGO_SINGLELEADERLONG)
	    optname = argv[curopt]+1;
	else
	    return -1;
    } else {
	optname = argv[curopt]+2;
    }

    /* Do first longest-match search if requested */
    if (flags & UGO_LONGOPTADJACENT) {
	size_t matchlen = 0;
	int matchind = -1;
	for (i=0; longopts[i].name != NULL; i++) {
	    size_t longnamelen = strlen(longopts[i].name);
	    if (longnamelen > matchlen
		&& optncmp(optname, longopts[i].name, longnamelen) == 0) {
		matchind = i;
		matchlen = longnamelen;
	    }
	}

	if (matchlen > 0) {
	    /* See if our match has an adjacent argument */
	    if (optname[matchlen] != '\0') {
		/* Strip assigner character if present */
		if (strchr(assigners, optname[matchlen]))
		    *longarg = optname+matchlen+1;
		else
		    *longarg = optname+matchlen;
	    }

	    return matchind;
	}

	return -1;
    }

    /* Check for assigner in the option */
    alen = strlen(assigners);
    for (i=0; (unsigned)i < alen; i++) {
	char *asn = strchr(optname, assigners[i]);
	if (asn != NULL) {
	    optnamelen = asn - optname;
	    *longarg = asn+1;
	    break;
	}
    }

    if (optnamelen == 0)
	optnamelen = strlen(optname);

    for (i=0; longopts[i].name != NULL; i++)
	if (optncmp(optname, longopts[i].name, optnamelen) == 0
	    && strlen(longopts[i].name) == optnamelen)
	    return i;

    return -1;
}

/* Check if an option has a separate argument (in the following argv[] index) */
static int has_separate_argument(int curopt, int argc, char *const argv[],
				 const char *shortopts,
				 const struct option *longopts,
				 const char *assigners, const char *optleaders,
				 int flags)
{
    int longind;
    char *longarg;

    assert(curopt < argc && like_option(argv[curopt], optleaders));

    /* Check if we have a long option */
    longind = match_longopt(ultraoptind, argv, longopts, assigners, optleaders,
			    flags, &longarg);
    if (longind >= 0) {
	if (longopts[longind].has_arg == no_argument
	    || longarg != NULL
	    || (longopts[longind].has_arg == optional_argument
		&& !(flags & UGO_SEPARATEDOPTIONAL)))
	    return 0;

	return like_optarg(argv[curopt+1], optleaders,
		    (flags & UGO_HYPHENARG) &&
		    longopts[longind].has_arg == required_argument);
    } else if (!strchr(optleaders, argv[curopt][1])) {
	/* Short option */
	char *optpos;

	optpos = strchr(shortopts, argv[curopt][1]);
	if ((flags & UGO_CASEINSENSITIVE) && optpos == NULL) {
	    if (islower(argv[curopt][1]))
		optpos = strchr(shortopts, toupper(argv[curopt][1]));
	    else
		optpos = strchr(shortopts, tolower(argv[curopt][1]));
	}

	
	return optpos != NULL			/* Option found */
	       && optpos[1] == ':'		/* Option takes argument */
	       && (optpos[2] != ':' || (flags & UGO_SEPARATEDOPTIONAL))
	       && argv[curopt][2] == '\0'	/* Argument is not adjacent */
	       && like_optarg(argv[curopt+1],	/* Is an argument */
		    optleaders,
		    (flags & UGO_HYPHENARG) && optpos[2] != ':');
    }

    /* No match */
    return 0;
}

/* Bring the next option, or terminator, up to ultraoptind if there is one
 * Returns number of words shifted forward
 */
static int permute_options(int argc, char *argv[], const char *shortopts,
			   const struct option *longopts,
			   const char *assigners, const char *optleaders,
			   int flags)
{
    int curopt = ultraoptind;

    /* If we already have an option or no more possible, give up */
    if (curopt >= argc || like_option(argv[curopt], optleaders))
	return 0;

    for ( ; curopt < argc && argv[curopt]; curopt++) {
	int shiftarg = 0;
	int i;

	/* Permute options and the option terminator */
	if (like_option(argv[curopt], optleaders)) {
	    /* Check if we need to shift argument too */
	    shiftarg = has_separate_argument(curopt, argc, argv, shortopts,
					     longopts, assigners, optleaders,
					     flags);
	} else if (!like_optterm(argv[curopt], optleaders)) {
	    continue;
	}

	/* Shift option */
	for (i=curopt; i>ultraoptind; i--) {
	    char *temp = argv[i];
	    argv[i] = argv[i-1];
	    argv[i-1] = temp;

	    if (shiftarg) {
		temp = argv[i+1];
		argv[i+1] = argv[i];
		argv[i] = temp;
	    }
	}

	/* All done */
	if (shiftarg)
	    return 2;
	else
	    return 1;
    }

    /* Couldn't find an option, bummer */
    return 0;
}

/* Handle a longopts[longind] matches argv[ultraoptind] actions */
static int handle_longopt(int longind, char *longarg, int noseparg,
			  char *const argv[],
			  const struct option *longopts, int *indexptr,
			  const char *optleaders, int flags)
{
    /* Handle assignment arguments */
    if (longarg && longopts[longind].has_arg == no_argument) {
	print_error(flags, errorarg, argv[0],
		    longarg-argv[ultraoptind]-1, argv[ultraoptind]);
	/* TODO:  What is a good value to put in ultraoptopt? */
	/* Looks like GNU getopt() uses val */
	ultraoptopt = longopts[longind].val;
	ultraoptind++;
	return '?';
    } else if (longarg) {
	ultraoptind++;
	ultraoptarg = longarg;

	if (indexptr)
	    *indexptr = longind;

	if (longopts[longind].flag) {
	    *(longopts[longind].flag) = longopts[longind].val;
	    return 0;
	} else
	    return longopts[longind].val;
    }

    /* Handle missing required argument */
    if (longopts[longind].has_arg == required_argument
	&& (noseparg
	    || !like_optarg(argv[ultraoptind+1],
		    optleaders,
		    flags & UGO_HYPHENARG))) {
	print_error(flags, errornoarg, argv[0],
		    strlen(argv[ultraoptind]), argv[ultraoptind]);
	ultraoptind++;
	if (flags & UGO_MISSINGCOLON)
	    return ':';
	else
	    return '?';
    }

    /* Handle available argument */
    if ((longopts[longind].has_arg == required_argument
	 || (longopts[longind].has_arg == optional_argument
	     && (flags & UGO_SEPARATEDOPTIONAL)))
	&& !noseparg
	&& like_optarg(argv[ultraoptind+1],
		optleaders,
		(flags & UGO_HYPHENARG) &&
		longopts[longind].has_arg == required_argument)) {
	ultraoptarg = argv[ultraoptind+1];
	ultraoptind += 2;
    } else
	ultraoptind++;

    if (indexptr)
	*indexptr = longind;

    if (longopts[longind].flag) {
	*(longopts[longind].flag) = longopts[longind].val;
	return 0;
    } else
	return longopts[longind].val;
}

int ultragetopt_tunable(int argc, char *const argv[], const char *shortopts,
			const struct option *longopts, int *indexptr,
			const char *assigners, const char *optleaders,
			int flags)
{
    char *opt;		/* Option we are processing */
    char *optpos;	/* Pointer to opt in shortopts */
    int noseparg = 0;	/* Force option not to have a separate argument */

    if (ultraoptreset) {
	ultraoptind = 1;
	ultraopterr = 1;
	ultraoptnum = 0;
	ultraoptreset = 0;
    }

    ultraoptarg = NULL;
#ifdef ULTRAGETOPT_DEFAULTOPTOPT
    ultraoptopt = ULTRAGETOPT_DEFAULTOPTOPT -0;
#endif

    /* Sanity check (These are specified verbatim in SUS) */
    if (ultraoptind > argc
	|| argv[ultraoptind] == NULL)
	return -1;

    /* No permuting when $POSIXLY_CORRECT is set (to match GNU getopt) */
    if (getenv("POSIXLY_CORRECT"))
	flags &= ~UGO_OPTIONPERMUTE;

    /* Get flags from shortopts */
    for ( ; shortopts && *shortopts; shortopts++) {
	if (*shortopts == '+')
	    flags &= ~UGO_OPTIONPERMUTE;
	else if (*shortopts == '-')
	    flags |= UGO_NONOPTARG;
	else if (*shortopts == ':') {
	    flags |= UGO_NOPRINTERR;
	    flags |= UGO_MISSINGCOLON;
	} else
	    break;
    }

    /* Found non-option */
    if (!like_option(argv[ultraoptind], optleaders)) {
	int shifted;

	if (like_optterm(argv[ultraoptind], optleaders)) {
	    if (!(flags & UGO_NOEATDASHDASH))
		ultraoptind++;

	    return -1;
	}

	if (flags & UGO_NONOPTARG) {
	    ultraoptarg = argv[ultraoptind];
	    ultraoptind++;
	    return 1;
	}

	if (!(flags & UGO_OPTIONPERMUTE))
	    return -1;

	shifted = permute_options(argc, (char **)argv, shortopts, longopts,
				  assigners, optleaders, flags);
	if (shifted == 0)
	    return -1;
	else if (shifted == 1)
	    noseparg = 1;

	if (like_optterm(argv[ultraoptind], optleaders)) {
	    if (!(flags & UGO_NOEATDASHDASH))
		ultraoptind++;

	    return -1;
	}
    }

    /* At this point we must have an option of some sort */
    assert(like_option(argv[ultraoptind], optleaders));

    /* Handle --* */
    if (argv[ultraoptind][0] == argv[ultraoptind][1]) {
	int longind;
	char *longarg;

	/* Handle long option */
	longind = match_longopt(ultraoptind, argv, longopts, assigners,
				optleaders, flags, &longarg);
	if (longind < 0) {
	    if (longarg == NULL)
		print_error(flags, erroropt, argv[0],
			    strlen(argv[ultraoptind]), argv[ultraoptind]);
	    else
		print_error(flags, erroropt, argv[0],
			    longarg - argv[ultraoptind] - 1, argv[ultraoptind]);

	    /* TODO:  What is a good value for optopt in this case? */
	    /*	      Looks like BSD uses 0 */
	    ultraoptopt = 0;
	    ultraoptind++;
	    return '?';
	}

	return handle_longopt(longind, longarg, noseparg, argv,
			      longopts, indexptr, optleaders, flags);
    }

    /* See if it matches a long-only option */
    if (longopts != NULL &&
	    ultraoptnum == 0 &&
	    ((flags & UGO_SINGLELEADERLONG) ||
	     (flags & UGO_SINGLELEADERONLY))) {
	int longind;
	char *longarg;

	longind = match_longopt(ultraoptind, argv, longopts, assigners,
				optleaders, flags, &longarg);

	if (longind >= 0)
	    return handle_longopt(longind, longarg, noseparg, argv,
				  longopts, indexptr, optleaders, flags);
    }

    /* No long matches, process short option */
    opt = argv[ultraoptind] + ultraoptnum + 1;
    optpos = strchr(shortopts, opt[0]);
    if (optpos == NULL && (flags & UGO_CASEINSENSITIVE)) {
	if (islower(opt[0]))
	    optpos = strchr(shortopts, toupper(opt[0]));
	else
	    optpos = strchr(shortopts, tolower(opt[0]));
    }

    /* This could indicate ultraoptnum not being reset properly */
    assert(opt[0] != '\0');

    /* Check for invalid or unrecognized option */
    if (optpos == NULL || opt[0] == ':') {
	print_error(flags, erroroptc, argv[0], opt[0]);

	ultraoptopt = opt[0];
	if (opt[1] != '\0')
	    ultraoptnum++;
	else {
	    ultraoptnum = 0;
	    ultraoptind++;
	}

	return '?';
    }

    /* Handle arguments */
    if (optpos[1] == ':') {
	ultraoptnum = 0;

	/* Handle adjacent arguments -ofile.txt */
	if (opt[1] != '\0') {
	    /* Skip over assignment character */
	    if ((flags & UGO_SHORTOPTASSIGN) && strchr(assigners, opt[1]))
		ultraoptarg = opt + 2;
	    else
		ultraoptarg = opt + 1;

	    ultraoptind++;
	    return optpos[0];
	}

	/* Handle optional argument not present */
	if ((flags & UGO_OPTIONALARG)		    /* accept optionals */
	    && optpos[2] == ':'			    /* opt takes optional */
	    && (argv[ultraoptind+1] == NULL	    /* optional doesn't exist */
		|| !(flags & UGO_SEPARATEDOPTIONAL) /* separated not accepted */
		|| like_option(argv[ultraoptind+1], optleaders))) {
	    ultraoptind++;
	    return optpos[0];
	}

	/* Handle separated argument missing */
	if (ultraoptind+2 > argc
	    || noseparg
	    || !like_optarg(argv[ultraoptind+1],
		    optleaders,
		    (flags & UGO_HYPHENARG))) {
	    ultraoptind++;
	    print_error(flags, errornoargc, argv[0], opt[0]);

	    ultraoptopt = opt[0];
	    if (flags & UGO_MISSINGCOLON)
		return ':';
	    else
		return '?';
	}

	ultraoptind += 2;
	ultraoptarg = argv[ultraoptind-1];
	return optpos[0];
    }

    /* Handle argumentless option with assigned option */
    if ((flags & UGO_SHORTOPTASSIGN)
	&& opt[1] != '\0' && strchr(assigners, opt[1])) {
	print_error(flags, errorargc, argv[0], opt[0]);
	ultraoptnum = 0;
	ultraoptopt = opt[0];
	ultraoptind++;
	return '?';
    }

    if (opt[1] != '\0') {
	ultraoptnum++;
    } else {
	ultraoptnum = 0;
	ultraoptind++;
    }
    
    return optpos[0];
}

/* POSIX-compliant getopt
 *
 * Handles optional argument '::' specifier as an extension for compatibility
 * with glibc
 */
int ultragetopt(int argc, char * const argv[], const char *optstring)
{
    int flags = getoptflags;

#ifdef ULTRAGETOPT_OPTIONPERMUTE
    flags |= UGO_OPTIONPERMUTE;
#endif

#ifndef ULTRAGETOPT_NO_OPTIONALARG
    flags |= UGO_OPTIONALARG;
#endif

    return ultragetopt_tunable(argc, argv, optstring, NULL, NULL,
			       unixassigners, unixleaders, flags);
}

/* GNU getopt_long workalike
 *
 * Argument reordering not yet implemented
 * Leading + and - under consideration (behavior violates POSIX...)
 */
int ultragetopt_long(int argc, char *const argv[], const char *shortopts,
		const struct option *longopts, int *indexptr)
{
    return ultragetopt_tunable(argc, argv, shortopts, longopts, indexptr,
			       unixassigners, unixleaders,
			       getoptflags | UGO_OPTIONPERMUTE | UGO_OPTIONALARG);
}

/* GNU getopt_long_only workalike */
int ultragetopt_long_only(int argc, char *const argv[], const char *shortopts,
			  const struct option *longopts, int *indexptr)
{
    return ultragetopt_tunable(argc, argv, shortopts, longopts, indexptr,
			       unixassigners, unixleaders,
			       getoptflags | UGO_SINGLELEADERLONG
			       | UGO_OPTIONPERMUTE | UGO_OPTIONALARG);
}

int ultragetopt_dos(int argc, char * const argv[], const char *optstring)
{
    return ultragetopt_tunable(argc, argv, optstring, NULL, NULL,
			       dosassigners, dosleaders,
			       getoptflags | UGO_CASEINSENSITIVE);
}

int ultragetopt_long_dos(int argc, char *const argv[], const char *shortopts,
			 const struct option *longopts, int *indexptr)
{
    return ultragetopt_tunable(argc, argv, shortopts, longopts, indexptr,
			       dosassigners, dosleaders,
			       getoptflags | UGO_CASEINSENSITIVE
			       | UGO_SINGLELEADERLONG | UGO_SINGLELEADERONLY
			       | UGO_OPTIONPERMUTE | UGO_OPTIONALARG);
}

/* vim:set sts=4 sw=4: */