77 lines
1.9 KiB
C
77 lines
1.9 KiB
C
/*
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FUNCTION
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<<mbstowcs>>---minimal multibyte string to wide char converter
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INDEX
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mbstowcs
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SYNOPSIS
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#include <stdlib.h>
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int mbstowcs(wchar_t *restrict <[pwc]>, const char *restrict <[s]>, size_t <[n]>);
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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 <<mbstowcs>>. In this case, the
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only ``multi-byte character sequences'' recognized are single bytes,
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and they are ``converted'' to wide-char versions simply by byte
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extension.
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When _MB_CAPABLE is defined, this routine calls <<_mbstowcs_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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RETURNS
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This implementation of <<mbstowcs>> returns <<0>> if
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<[s]> is <<NULL>> or is the empty string;
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it returns <<-1>> if _MB_CAPABLE and one of the
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multi-byte characters is invalid or incomplete;
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otherwise it returns the minimum of: <<n>> or the
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number of multi-byte characters in <<s>> plus 1 (to
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compensate for the nul character).
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If the return value is -1, the state of the <<pwc>> string is
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indeterminate. If the input has a length of 0, the output
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string will be modified to contain a wchar_t nul terminator.
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PORTABILITY
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<<mbstowcs>> is required in the ANSI C standard. However, the precise
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effects vary with the locale.
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<<mbstowcs>> requires no supporting OS subroutines.
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*/
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#ifndef _REENT_ONLY
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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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size_t
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_DEFUN (mbstowcs, (pwcs, s, n),
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wchar_t *__restrict pwcs,
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const char *__restrict s,
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size_t n)
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{
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#ifdef _MB_CAPABLE
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mbstate_t state;
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state.__count = 0;
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return _mbstowcs_r (_REENT, pwcs, s, n, &state);
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#else /* not _MB_CAPABLE */
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int count = 0;
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if (n != 0) {
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do {
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if ((*pwcs++ = (wchar_t) *s++) == 0)
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break;
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count++;
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} while (--n != 0);
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}
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return count;
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#endif /* not _MB_CAPABLE */
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}
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#endif /* !_REENT_ONLY */
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