1mbrtowc(3C) Standard C Library Functions mbrtowc(3C)
2
6 mbrtowc - convert a character to a wide-character code (restartable)
7
9 #include <wchar.h>
10 size_t mbrtowc(wchar_t *restrict pwc, const char *restrict s, size_t n,
12 mbstate_t *restrict ps);
13
16 If s is a null pointer, the mbrtowc() function is equivalent to the
17 call:
18 mbrtowc(NULL, ``'', 1, ps)
20 In this case, the values of the arguments pwc and n are ignored.
24 If s is not a null pointer, the mbrtowc() function inspects at most n
27 bytes beginning at the byte pointed to by s to determine the number of
28 bytes needed to complete the next character (including any shift
29 sequences). If the function determines that the next character is com‐
30 pleted, it determines the value of the corresponding wide-character and
31 then, if pwc is not a null pointer, stores that value in the object
32 pointed to by pwc. If the corresponding wide-character is the null
33 wide-character, the resulting state described is the initial conversion
34 state.
35 If ps is a null pointer, the mbrtowc() function uses its own internal
38 mbstate_t object, which is initialized at program startup to the ini‐
39 tial conversion state. Otherwise, the mbstate_t object pointed to by
40 ps is used to completely describe the current conversion state of the
41 associated character sequence. Solaris will behave as if no function
42 defined in the Solaris Reference Manual calls mbrtowc().
43 The behavior of this function is affected by the LC_CTYPE category of
46 the current locale. See environ(5).
47
49 The mbrtowc() function returns the first of the following that applies:
50 0 If the next n or fewer bytes complete the character
52 that corresponds to the null wide-character (which is
53 the value stored).
54 positive If the next n or fewer bytes complete a valid charac‐
57 ter (which is the value stored); the value returned is
58 the number of bytes that complete the character.
59 (size_t)−2 If the next n bytes contribute to an incomplete but
62 potentially valid character, and all n bytes have
63 been processed (no value is stored). When n has at
64 least the value of the MB_CUR_MAX macro, this case can
65 only occur if s points at a sequence of redundant
66 shift sequences (for implementations with state-depen‐
67 dent encodings).
68 (size_t)−1 If an encoding error occurs, in which case the next n
71 or fewer bytes do not contribute to a complete and
72 valid character (no value is stored). In this case,
73 EILSEQ is stored in errno and the conversion state is
74 undefined.
75
78 The mbrtowc() function may fail if:
79 EINVAL The ps argument points to an object that contains an invalid
81 conversion state.
82 EILSEQ Invalid character sequence is detected.
85
88 See attributes(5) for descriptions of the following attributes:
89 ┌─────────────────────────────┬─────────────────────────────┐
94 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
95 ├─────────────────────────────┼─────────────────────────────┤
96 │Interface Stability │Standard │
97 ├─────────────────────────────┼─────────────────────────────┤
98 │MT-Level │See NOTES below │
99 └─────────────────────────────┴─────────────────────────────┘
100
102 mbsinit(3C), setlocale(3C), attributes(5), environ(5), standards(5)
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105 If ps is not a null pointer, mbrtowc() uses the mbstate_t object
106 pointed to by ps and the function can be used safely in multithreaded
107 applications, as long as setlocale(3C) is not being called to change
108 the locale. If ps is a null pointer, mbrtowc() uses its internal
109 mbstate_t object and the function is Unsafe in multithreaded applica‐
110 tions.
111SunOS 5.11 1 Nov 2003 mbrtowc(3C)