97 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
			
		
		
	
	
			97 lines
		
	
	
		
			2.4 KiB
		
	
	
	
		
			C
		
	
	
	
| /*
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| FUNCTION
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| <<mbtowc>>---minimal multibyte to wide char converter
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| 
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| INDEX
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| 	mbtowc
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| 
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| ANSI_SYNOPSIS
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| 	#include <stdlib.h>
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| 	int mbtowc(wchar_t *restrict <[pwc]>, const char *restrict <[s]>, size_t <[n]>);
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| 
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| TRAD_SYNOPSIS
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| 	#include <stdlib.h>
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| 	int mbtowc(<[pwc]>, <[s]>, <[n]>)
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| 	wchar_t *<[pwc]>;
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| 	const char *<[s]>;
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| 	size_t <[n]>;
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| 
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| DESCRIPTION
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| When _MB_CAPABLE is not defined, this is a minimal ANSI-conforming 
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| implementation of <<mbtowc>>.  In this case,
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| only ``multi-byte character sequences'' recognized are single bytes,
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| and they are ``converted'' to themselves.
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| Each call to <<mbtowc>> copies one character from <<*<[s]>>> to
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| <<*<[pwc]>>>, unless <[s]> is a null pointer.  The argument n
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| is ignored.
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| 
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| When _MB_CAPABLE is defined, this routine calls <<_mbtowc_r>> to perform
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| the conversion, passing a state variable to allow state dependent
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| decoding.  The result is based on the locale setting which may
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| be restricted to a defined set of locales.
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| 
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| RETURNS
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| This implementation of <<mbtowc>> returns <<0>> if
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| <[s]> is <<NULL>> or is the empty string; 
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| it returns <<1>> if not _MB_CAPABLE or
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| the character is a single-byte character; it returns <<-1>>
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| if n is <<0>> or the multi-byte character is invalid; 
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| otherwise it returns the number of bytes in the multibyte character.
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| If the return value is -1, no changes are made to the <<pwc>>
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| output string.  If the input is the empty string, a wchar_t nul
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| is placed in the output string and 0 is returned.  If the input
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| has a length of 0, no changes are made to the <<pwc>> output string.
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| 
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| PORTABILITY
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| <<mbtowc>> is required in the ANSI C standard.  However, the precise
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| effects vary with the locale.
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| 
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| <<mbtowc>> requires no supporting OS subroutines.
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| */
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| 
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| #ifndef _REENT_ONLY
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| 
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| #include <newlib.h>
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| #include <stdlib.h>
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| #include <wchar.h>
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| #include "local.h"
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| 
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| int
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| _DEFUN (mbtowc, (pwc, s, n),
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|         wchar_t *__restrict pwc _AND
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|         const char *__restrict s _AND
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|         size_t n)
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| {
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| #ifdef _MB_CAPABLE
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|   int retval = 0;
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|   struct _reent *reent = _REENT;
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|   mbstate_t *ps;
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| 
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|   _REENT_CHECK_MISC(reent);
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|   ps = &(_REENT_MBTOWC_STATE(reent));
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|   
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|   retval = __MBTOWC (reent, pwc, s, n, ps);
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|   
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|   if (retval < 0)
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|     {
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|       ps->__count = 0;
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|       return -1;
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|     }
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|   return retval;
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| #else /* not _MB_CAPABLE */
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|   if (s == NULL)
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|     return 0;
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|   if (n == 0)
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|     return -1;
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|   if (pwc)
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|     *pwc = (wchar_t) *s;
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|   return (*s != '\0');
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| #endif /* not _MB_CAPABLE */
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| }
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| 
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| #endif /* !_REENT_ONLY */
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| 
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| 
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| 
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| 
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