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newlib/winsup/mingw/mingwex/getopt.c

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/*
* 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 */
/* Some BSD applications expect to be able to reinitialise `getopt' parsing
* by setting a global variable called `optreset'. We provide an obfuscated
* API, which allows applications to emulate this brain damage; however, any
* use of this is non-portable, and is strongly discouraged.
*/
#define optreset __mingw_optreset
int optreset = 0;
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;
/* On return, `optind' should normally refer to the argument, if any,
* which follows the current one; it is convenient to set this, before
* checking for the presence of any `optarg'.
*/
optind = *argind + 1;
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( optind < argc )
/*
* ... except that the requirement may be satisfied from
* the following command line argument, if any ...
*/
optarg = argv[*argind = optind++];
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( opt[index].flag != NULL )
{
/* ... then we place the proper return value there,
* and return a status code of zero ...
*/
*(opt[index].flag) = 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 int optbase = 0;
static const CHAR *nextchar = NULL;
static int optmark = 0;
if( (optreset |= (optind < 1)) || (optind < optbase) )
{
/* POSIX does not prescribe any definitive mechanism for restarting
* a `getopt' scan, but some applications may require such capability.
* We will support it, by allowing the caller to adjust the value of
* `optind' downwards, (nominally setting it to zero). Since POSIX
* wants `optind' to have an initial value of one, but we want all
* of our internal place holders to be initialised to zero, when we
* are called for the first time, we will handle such a reset by
* adjusting all of the internal place holders to one less than
* the adjusted `optind' value, (but never to less than zero).
*/
if( optreset )
{
/* User has explicitly requested reinitialisation...
* We need to reset `optind' to it's normal initial value of 1,
* to avoid a potential infinitely recursive loop; by doing this
* up front, we also ensure that the remaining place holders
* will be correctly reinitialised to no less than zero.
*/
optind = 1;
/* We also need to clear the `optreset' request...
*/
optreset = 0;
}
/* Now, we may safely reinitialise the internal place holders, to
* one less than `optind', without fear of making them negative.
*/
optmark = optbase = argind = optind - 1;
nextchar = NULL;
}
/* From a POSIX perspective, the following is `undefined behaviour';
* we implement it thus, for compatibility with GNU and BSD getopt.
*/
else if( optind > (argind + 1) )
{
/* Some applications expect to be able to manipulate `optind',
* causing `getopt' to skip over one or more elements of `argv';
* POSIX doesn't require us to support this brain-damaged concept;
* (indeed, POSIX defines no particular behaviour, in the event of
* such usage, so it must be considered a bug for an application
* to rely on any particular outcome); nonetheless, Mac-OS-X and
* BSD actually provide *documented* support for this capability,
* so we ensure that our internal place holders keep track of
* external `optind' increments; (`argind' must lag by one).
*/
argind = optind - 1;
/* When `optind' is misused, in this fashion, we also abandon any
* residual text in the argument we had been parsing; this is done
* without any further processing of such abandoned text, assuming
* that the caller is equipped to handle it appropriately.
*/
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 );
}
}
optind = argind + 1;
nextchar = NULL;
}
else
optarg = NULL;
optind = (nextchar && *nextchar) ? argind : argind + 1;
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 );
optind = (nextchar && *nextchar) ? argind : argind + 1;
return getopt_unknown;
}
if( optmark > optbase )
{
/* 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 >= optbase; --optmark )
arglist[optmark + optspan] = arglist[optmark];
/* restore the temporarily saved option arguments to
* their permuted location.
*/
for( index = 0; index < optspan; ++index )
arglist[optbase + index] = this_arg[index];
/* adjust `optbase', to account for the relocated option.
*/
optbase += optspan;
}
else
/* no permutation occurred ...
* simply adjust `optbase' for all options parsed so far.
*/
optbase = 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 > optbase )
{
/* 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-- > optbase );
/* reinstate the `--' marker, in its permuted location.
*/
arglist[optbase] = this_arg;
}
/* ... before finally bumping `optbase' past the `--' marker,
* and returning the `all done' completion indicator.
*/
optind = ++optbase;
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 ...
*/
optopt = 0;
nextchar = NULL;
optind = argind + 1;
complain( "option `%s' is ambiguous", argv[argind] );
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;
optind = argind + 1;
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;
optind = argind + 1;
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,
*/
optind = optbase;
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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