1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
/*
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>
#include <wchar.h>
int
_DEFUN (mblen, (s, n),
const char *s _AND
size_t n)
{
#ifdef MB_CAPABLE
int retval = 0;
mbstate_t *state;
_REENT_CHECK_MISC(_REENT);
state = &(_REENT_MBLEN_STATE(_REENT));
retval = _mbtowc_r (_REENT, NULL, s, n, state);
if (retval < 0)
{
state->__count = 0;
return -1;
}
else
return retval;
#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 */
|
