67 lines
1.7 KiB
C
67 lines
1.7 KiB
C
/*
|
|
FUNCTION
|
|
<<mblen>>---minimal multibyte length function
|
|
|
|
INDEX
|
|
mblen
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <stdlib.h>
|
|
int mblen(const char *<[s]>, size_t <[n]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
#include <stdlib.h>
|
|
int mblen(<[s]>, <[n]>)
|
|
const char *<[s]>;
|
|
size_t <[n]>;
|
|
|
|
DESCRIPTION
|
|
When MB_CAPABLE is not defined, this is a minimal ANSI-conforming
|
|
implementation of <<mblen>>. In this case, the
|
|
only ``multi-byte character sequences'' recognized are single bytes,
|
|
and thus <<1>> is returned unless <[s]> is the null pointer or
|
|
has a length of 0 or is the empty string.
|
|
|
|
When MB_CAPABLE is defined, this routine calls <<_mbtowc_r>> to perform
|
|
the conversion, passing a state variable to allow state dependent
|
|
decoding. The result is based on the locale setting which may
|
|
be restricted to a defined set of locales.
|
|
|
|
RETURNS
|
|
This implementation of <<mblen>> returns <<0>> if
|
|
<[s]> is <<NULL>> or the empty string; it returns <<1>> if not MB_CAPABLE or
|
|
the character is a single-byte character; it returns <<-1>>
|
|
if the multi-byte character is invalid; otherwise it returns
|
|
the number of bytes in the multibyte character.
|
|
|
|
PORTABILITY
|
|
<<mblen>> is required in the ANSI C standard. However, the precise
|
|
effects vary with the locale.
|
|
|
|
<<mblen>> requires no supporting OS subroutines.
|
|
*/
|
|
|
|
#ifndef _REENT_ONLY
|
|
|
|
#include <stdlib.h>
|
|
|
|
int
|
|
_DEFUN (mblen, (s, n),
|
|
const char *s _AND
|
|
size_t n)
|
|
{
|
|
#ifdef MB_CAPABLE
|
|
static int state;
|
|
|
|
return _mbtowc_r (_REENT, NULL, s, n, &state);
|
|
#else /* not MB_CAPABLE */
|
|
if (s == NULL || *s == '\0')
|
|
return 0;
|
|
if (n == 0)
|
|
return -1;
|
|
return 1;
|
|
#endif /* not MB_CAPABLE */
|
|
}
|
|
|
|
#endif /* !_REENT_ONLY */
|