+/*
+ * getopt.c
+ *
+ * $Id$
+ *
+ * Implementation of the `getopt', `getopt_long' and `getopt_long_only'
+ * APIs, for inclusion in the MinGW runtime library.
+ *
+ * This file is part of the MinGW32 package set.
+ *
+ * Contributed by Keith Marshall <keithmarshall@users.sourceforge.net>
+ *
+ *
+ * THIS SOFTWARE IS NOT COPYRIGHTED
+ *
+ * This source code is offered for use in the public domain. You may
+ * use, modify or distribute it freely.
+ *
+ * This code is distributed in the hope that it will be useful but
+ * WITHOUT ANY WARRANTY. ALL WARRANTIES, EXPRESS OR IMPLIED ARE HEREBY
+ * DISCLAIMED. This includes but is not limited to warranties of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * $Revision$
+ * $Author$
+ * $Date$
+ *
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+#include <getopt.h>
+
+/* Identify how to get the calling program name, for use in messages...
+ */
+#ifdef __CYGWIN__
+/*
+ * CYGWIN uses this DLL reference...
+ */
+# define PROGNAME __progname
+extern char __declspec(dllimport) *__progname;
+#else
+/*
+ * ...while elsewhere, we simply use the first argument passed.
+ */
+# define PROGNAME *argv
+#endif
+
+/* Initialise the public variables. */
+
+int optind = 1; /* index for first non-option arg */
+int opterr = 1; /* enable built-in error messages */
+
+char *optarg = NULL; /* pointer to current option argument */
+
+#define CHAR char /* argument type selector */
+
+#define getopt_switchar '-' /* option prefix character in argv */
+#define getopt_pluschar '+' /* prefix for POSIX mode in optstring */
+#define getopt_takes_argument ':' /* marker for optarg in optstring */
+#define getopt_arg_assign '=' /* longopt argument field separator */
+#define getopt_unknown '?' /* return code for unmatched option */
+#define getopt_ordered 1 /* return code for ordered non-option */
+
+#define getopt_all_done -1 /* return code to indicate completion */
+
+enum
+{ /* All `getopt' API functions are implemented via calls to the
+ * common static function `getopt_parse()'; these `mode' selectors
+ * determine the behaviour of `getopt_parse()', to deliver the
+ * appropriate result in each case.
+ */
+ getopt_mode_standard = 0, /* getopt() */
+ getopt_mode_long, /* getopt_long() */
+ getopt_mode_long_only /* getopt_long_only() */
+};
+
+enum
+{ /* When attempting to match a command line argument to a long form option,
+ * these indicate the status of the match.
+ */
+ getopt_no_match = 0, /* no successful match */
+ getopt_abbreviated_match, /* argument is an abbreviation for an option */
+ getopt_exact_match /* argument matches the full option name */
+};
+
+int optopt = getopt_unknown; /* return value for option being evaluated */
+
+static __inline__
+int getopt_missing_arg( const CHAR *optstring )
+{
+ /* Helper function to determine the appropriate return value,
+ * for the case where a required option argument is missing.
+ */
+ if( (*optstring == getopt_pluschar) || (*optstring == getopt_switchar) )
+ ++optstring;
+ return (*optstring == getopt_takes_argument)
+ ? getopt_takes_argument
+ : getopt_unknown;
+}
+
+/* `complain' macro facilitates the generation of simple built-in
+ * error messages, displayed on various fault conditions, provided
+ * `opterr' is non-zero.
+ */
+#define complain( MSG, ARG ) if( opterr ) \
+ fprintf( stderr, "%s: "MSG"\n", PROGNAME, ARG )
+
+static __inline__
+int getopt_argerror( int mode, char *fmt, CHAR *prog, struct option *opt, int retval )
+{
+ /* Helper function, to generate more complex built-in error
+ * messages, for invalid arguments to long form options ...
+ */
+ if( opterr )
+ {
+ /* ... but, displayed only if `opterr' is non-zero.
+ */
+ char flag[] = "--";
+ if( mode != getopt_mode_long )
+ /*
+ * only display one hyphen, for implicit long form options,
+ * improperly resolved by `getopt_long_only()'.
+ */
+ flag[1] = 0;
+ /*
+ * always preface the program name ...
+ */
+ fprintf( stderr, "%s: ", prog );
+ /*
+ * to the appropriate, option specific message.
+ */
+ fprintf( stderr, fmt, flag, opt->name );
+ }
+ /* Whether displaying the message, or not, always set `optopt'
+ * to identify the faulty option ...
+ */
+ optopt = opt->val;
+ /*
+ * and return the `invalid option' indicator.
+ */
+ return retval;
+}
+
+/* `getopt_conventions' establish behavioural options, to control
+ * the operation of `getopt_parse()', e.g. to select between POSIX
+ * and GNU style argument parsing behaviour.
+ */
+#define getopt_set_conventions 0x1000
+#define getopt_posixly_correct 0x0010
+
+static __inline__
+int getopt_conventions( int flags )
+{
+ static int conventions = 0;
+
+ if( (conventions == 0) && ((flags & getopt_set_conventions) == 0) )
+ {
+ /* default conventions have not yet been established;
+ * initialise them now!
+ */
+ conventions = getopt_set_conventions;
+ if( (flags == getopt_pluschar) || (getenv( "POSIXLY_CORRECT" ) != NULL) )
+ conventions |= getopt_posixly_correct;
+ }
+
+ else if( flags & getopt_set_conventions )
+ /*
+ * default conventions may have already been established,
+ * but this is a specific request to augment them.
+ */
+ conventions |= flags;
+
+ /* in any event, return the currently established conventions.
+ */
+ return conventions;
+}
+
+static __inline__
+int is_switchar( CHAR flag )
+{
+ /* A simple helper function, used to identify the switch character
+ * introducing an optional command line argument.
+ */
+ return flag == getopt_switchar;
+}
+
+static __inline__
+const CHAR *getopt_match( CHAR lookup, const CHAR *opt_string )
+{
+ /* Helper function, used to identify short form options.
+ */
+ if( (*opt_string == getopt_pluschar) || (*opt_string == getopt_switchar) )
+ ++opt_string;
+ if( *opt_string == getopt_takes_argument )
+ ++opt_string;
+ do if( lookup == *opt_string ) return opt_string;
+ while( *++opt_string );
+ return NULL;
+}
+
+static __inline__
+int getopt_match_long( const CHAR *nextchar, const CHAR *optname )
+{
+ /* Helper function, used to identify potential matches for
+ * long form options.
+ */
+ CHAR matchchar;
+ while( (matchchar = *nextchar++) && (matchchar == *optname) )
+ /*
+ * skip over initial substring which DOES match.
+ */
+ ++optname;
+
+ if( matchchar )
+ {
+ /* did NOT match the entire argument to an initial substring
+ * of a defined option name ...
+ */
+ if( matchchar != getopt_arg_assign )
+ /*
+ * ... and didn't stop at an `=' internal field separator,
+ * so this is NOT a possible match.
+ */
+ return getopt_no_match;
+
+ /* DID stop at an `=' internal field separator,
+ * so this IS a possible match, and what follows is an
+ * argument to the possibly matched option.
+ */
+ optarg = (char *)(nextchar);
+ }
+ return *optname
+ /*
+ * if we DIDN'T match the ENTIRE text of the option name,
+ * then it's a possible abbreviated match ...
+ */
+ ? getopt_abbreviated_match
+ /*
+ * but if we DID match the entire option name,
+ * then it's a DEFINITE EXACT match.
+ */
+ : getopt_exact_match;
+}
+
+static __inline__
+int getopt_resolved( int mode, int argc, CHAR *const *argv, int *argind,
+struct option *opt, int index, int *retindex, const CHAR *optstring )
+{
+ /* Helper function to establish appropriate return conditions,
+ * on resolution of a long form option.
+ */
+ if( retindex != NULL )
+ *retindex = index;
+
+ if( optarg && (opt[index].has_arg == no_argument) )
+ /*
+ * it is an error for the user to specify an option specific argument
+ * with an option which doesn't expect one!
+ */
+ return getopt_argerror( mode, "option `%s%s' doesn't accept an argument\n",
+ PROGNAME, opt + index, getopt_unknown );
+
+ else if( (optarg == NULL) && (opt[index].has_arg == required_argument) )
+ {
+ /* similarly, it is an error if no argument is specified
+ * with an option which requires one ...
+ */
+ if( (*argind + 1) < argc )
+ /*
+ * ... except that the requirement may be satisfied from
+ * the following comand line argument, if any ...
+ */
+ optarg = argv[++*argind];
+
+ else
+ /* so fail this case, only if no such argument exists!
+ */
+ return getopt_argerror( mode, "option `%s%s' requires an argument\n",
+ PROGNAME, opt + index, getopt_missing_arg( optstring ) );
+ }
+
+ /* when the caller has provided a return buffer ...
+ */
+ if( retindex != NULL )
+ {
+ /* ... then we place the proper return value there,
+ * and return a status code of zero ...
+ */
+ *retindex = opt[index].val;
+ return 0;
+ }
+ /* ... otherwise, the return value becomes the status code.
+ */
+ return opt[index].val;
+}
+
+static
+#define getopt_std_args int argc, CHAR *const argv[], const CHAR *optstring
+int getopt_parse( int mode, getopt_std_args, ... )
+{
+ /* Common core implementation for ALL `getopt' functions.
+ */
+ static int argind = 0;
+ static const CHAR *nextchar = NULL;
+ static int optmark = 0;
+
+ if( (argind == 0) || (optind == 0) )
+ {
+ /* POSIX wants `optind' to have an initial value of one, but we want
+ * it to be initialised to zero, when we are called for the first time,
+ * (as indicated by `argind' having a value of zero). We also want to
+ * allow the caller to reset the `getopt' parser, causing it to scan
+ * the arguments again, (or to scan a new set of arguments); this
+ * may be achieved by the caller resetting `optind' to zero.
+ */
+ optmark = optind = argind = 0;
+ nextchar = NULL;
+ }
+
+ if( nextchar && *nextchar )
+ {
+ /* we are parsing a standard, or short format, option argument ...
+ */
+ const CHAR *optchar;
+ if( (optchar = getopt_match( optopt = *nextchar++, optstring )) != NULL )
+ {
+ /* we have identified it as valid ...
+ */
+ if( optchar[1] == getopt_takes_argument )
+ {
+ /* and determined that it requires an associated argument ...
+ */
+ if( ! *(optarg = (char *)(nextchar)) )
+ {
+ /* the argument is NOT attached ...
+ */
+ if( optchar[2] == getopt_takes_argument )
+ /*
+ * but this GNU extension marks it as optional,
+ * so we don't provide one on this occasion.
+ */
+ optarg = NULL;
+
+ /* otherwise this option takes a mandatory argument,
+ * so, provided there is one available ...
+ */
+ else if( (argc - argind) > 1 )
+ /*
+ * we take the following command line argument,
+ * as the appropriate option argument.
+ */
+ optarg = argv[++argind];
+
+ /* but if no further argument is available,
+ * then there is nothing we can do, except for
+ * issuing the requisite diagnostic message.
+ */
+ else
+ {
+ complain( "option requires an argument -- %c", optopt );
+ return getopt_missing_arg( optstring );
+ }
+ }
+ nextchar = NULL;
+ }
+ else
+ optarg = NULL;
+ return optopt;
+ }
+ /* if we didn't find a valid match for the specified option character,
+ * then we fall through to here, so take appropriate diagnostic action.
+ */
+ if( mode == getopt_mode_long_only )
+ {
+ complain( "unrecognised option `-%s'", --nextchar );
+ nextchar = NULL;
+ optopt = 0;
+ }
+ else complain( "invalid option -- %c", optopt );
+ return getopt_unknown;
+ }
+
+ if( optmark > optind )
+ {
+ /* This can happen, in GNU parsing mode ONLY, when we have
+ * skipped over non-option arguments, and found a subsequent
+ * option argument; in this case we permute the arguments.
+ */
+ int index;
+ /*
+ * `optspan' specifies the number of contiguous arguments
+ * which are spanned by the current option, and so must be
+ * moved together during permutation.
+ */
+ int optspan = argind - optmark + 1;
+ /*
+ * we use `this_arg' to store these temporarily.
+ */
+ CHAR *this_arg[optspan];
+ /*
+ * we cannot manipulate `argv' directly, since the `getopt'
+ * API prototypes it as `read-only'; this cast to `arglist'
+ * allows us to work around that restriction.
+ */
+ CHAR **arglist = (char **)(argv);
+
+ /* save temporary copies of the arguments which are associated
+ * with the current option ...
+ */
+ for( index = 0; index < optspan; ++index )
+ this_arg[index] = arglist[optmark + index];
+
+ /* move all preceding non-option arguments to the right,
+ * overwriting these saved arguments, while making space
+ * to replace them in their permuted location.
+ */
+ for( --optmark; optmark >= optind; --optmark )
+ arglist[optmark + optspan] = arglist[optmark];
+
+ /* restore the temporarily saved option arguments to
+ * their permuted location.
+ */
+ for( index = 0; index < optspan; ++index )
+ arglist[optind + index] = this_arg[index];
+
+ /* adjust `optind', to account for the relocated option.
+ */
+ optind += optspan;
+ }
+
+ else
+ /* no permutation occurred ...
+ * simply adjust `optind' for all options parsed so far.
+ */
+ optind = argind + 1;
+
+ /* enter main parsing loop ...
+ */
+ while( argc > ++argind )
+ {
+ /* inspect each argument in turn, identifying possible options ...
+ */
+ if( is_switchar( *(nextchar = argv[optmark = argind]) ) && *++nextchar )
+ {
+ /* we've found a candidate option argument ... */
+
+ if( is_switchar( *nextchar ) )
+ {
+ /* it's a double hyphen argument ... */
+
+ const CHAR *refchar = nextchar;
+ if( *++refchar )
+ {
+ /* and it looks like a long format option ...
+ * `getopt_long' mode must be active to accept it as such,
+ * `getopt_long_only' also qualifies, but we must downgrade
+ * it to force explicit handling as a long format option.
+ */
+ if( mode >= getopt_mode_long )
+ {
+ nextchar = refchar;
+ mode = getopt_mode_long;
+ }
+ }
+ else
+ {
+ /* this is an explicit `--' end of options marker, so wrap up now!
+ */
+ if( optmark > optind )
+ {
+ /* permuting the argument list as necessary ...
+ * (note use of `this_arg' and `arglist', as above).
+ */
+ CHAR *this_arg = argv[optmark];
+ CHAR **arglist = (CHAR **)(argv);
+
+ /* move all preceding non-option arguments to the right ...
+ */
+ do arglist[optmark] = arglist[optmark - 1];
+ while( optmark-- > optind );
+
+ /* reinstate the `--' marker, in its permuted location.
+ */
+ arglist[optind] = this_arg;
+ }
+ /* ... before finally bumping `optind' past the `--' marker,
+ * and returning the `all done' completion indicator.
+ */
+ ++optind;
+ return getopt_all_done;
+ }
+ }
+ else if( mode < getopt_mode_long_only )
+ {
+ /* it's not an explicit long option, and `getopt_long_only' isn't active,
+ * so we must explicitly try to match it as a short option.
+ */
+ mode = getopt_mode_standard;
+ }
+
+ if( mode >= getopt_mode_long )
+ {
+ /* the current argument is a long form option, (either explicitly,
+ * introduced by a double hyphen, or implicitly because we were called
+ * by `getopt_long_only'); this is where we parse it.
+ */
+ int lookup;
+ int matched = -1;
+
+ /* we need to fetch the `extra' function arguments, which are
+ * specified for the `getopt_long' APIs.
+ */
+ va_list refptr;
+ va_start( refptr, optstring );
+ struct option *longopts = va_arg( refptr, struct option * );
+ int *optindex = va_arg( refptr, int * );
+ va_end( refptr );
+
+ /* ensuring that `optarg' does not inherit any junk, from parsing
+ * preceding arguments ...
+ */
+ optarg = NULL;
+ for( lookup = 0; longopts && longopts[lookup].name; ++lookup )
+ {
+ /* scan the list of defined long form options ...
+ */
+ switch( getopt_match_long( nextchar, longopts[lookup].name ) )
+ {
+ /* looking for possible matches for the current argument.
+ */
+ case getopt_exact_match:
+ /*
+ * when an exact match is found,
+ * return it immediately, setting `nextchar' to NULL,
+ * to ensure we don't mistakenly try to match any
+ * subsequent characters as short form options.
+ */
+ nextchar = NULL;
+ return getopt_resolved( mode, argc, argv, &argind,
+ longopts, lookup, optindex, optstring );
+
+ case getopt_abbreviated_match:
+ /*
+ * but, for a partial (initial substring) match ...
+ */
+ if( matched >= 0 )
+ {
+ /* if this is not the first, then we have an ambiguity ...
+ */
+ complain( "option `%s' is ambiguous", argv[argind] );
+ nextchar = NULL;
+ optopt = 0;
+ return getopt_unknown;
+ }
+ /* otherwise just note that we've found a possible match ...
+ */
+ matched = lookup;
+ }
+ }
+ if( matched >= 0 )
+ {
+ /* if we get to here, then we found exactly one partial match,
+ * so return it, as for an exact match.
+ */
+ nextchar = NULL;
+ return getopt_resolved( mode, argc, argv, &argind,
+ longopts, matched, optindex, optstring );
+ }
+ if( mode < getopt_mode_long_only )
+ {
+ /* if here, then we had what SHOULD have been a long form option,
+ * but it is unmatched; (perversely, `mode == getopt_mode_long_only'
+ * allows us to still try to match it as a short form option).
+ */
+ optopt = 0;
+ nextchar = NULL;
+ complain( "unrecognised option `%s'", argv[argind] );
+ return getopt_unknown;
+ }
+ }
+ /* fall through to handle standard short form options...
+ * when the option argument format is neither explictly identified
+ * as long, nor implicitly matched as such, and the argument isn't
+ * just a bare hyphen, (which isn't an option), then we make one
+ * recursive call to explicitly interpret it as short format.
+ */
+ if( *nextchar )
+ return getopt_parse( mode, argc, argv, optstring );
+ }
+ /* if we get to here, then we've parsed a non-option argument ...
+ * in GNU compatibility mode, we step over it, so we can permute
+ * any subsequent option arguments, but ...
+ */
+ if( *optstring == getopt_switchar )
+ {
+ /* if `optstring' begins with a `-' character, this special
+ * GNU specific behaviour requires us to return the non-option
+ * arguments in strict order, as pseudo-arguments to a special
+ * option, with return value defined as `getopt_ordered'.
+ */
+ nextchar = NULL;
+ optarg = argv[argind];
+ return getopt_ordered;
+ }
+ if( getopt_conventions( *optstring ) & getopt_posixly_correct )
+ /*
+ * otherwise ...
+ * for POSIXLY_CORRECT behaviour, or if `optstring' begins with
+ * a `+' character, then we break out of the parsing loop, so that
+ * the scan ends at the current argument, with no permutation.
+ */
+ break;
+ }
+ /* fall through when all arguments have been evaluated,
+ */
+ return getopt_all_done;
+}
+
+/* All three public API entry points are trivially defined,
+ * in terms of the internal `getopt_parse' function.
+ */
+int getopt( getopt_std_args )
+{
+ return getopt_parse( getopt_mode_standard, argc, argv, optstring );
+}
+
+int getopt_long( getopt_std_args, const struct option *opts, int *index )
+{
+ return getopt_parse( getopt_mode_long, argc, argv, optstring, opts, index );
+}
+
+int getopt_long_only( getopt_std_args, const struct option *opts, int *index )
+{
+ return getopt_parse( getopt_mode_long_only, argc, argv, optstring, opts, index );
+}
+
+#ifdef __weak_alias
+/*
+ * These Microsnot style uglified aliases are provided for compatibility
+ * with the previous MinGW implementation of the getopt API.
+ */
+__weak_alias( getopt, _getopt )
+__weak_alias( getopt_long, _getopt_long )
+__weak_alias( getopt_long_only, _getopt_long_only )
+#endif
+
+/* $RCSfile$Revision$: end of file */
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