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mbtowc

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< c‎ | string‎ | multibyte
Revision as of 22:41, 31 May 2013 by P12bot (Talk | contribs)

Defined in header <stdlib.h>
int mbtowc( wchar_t          *pwc, const char          *s, size_t n )
(until C99)
int mbtowc( wchar_t *restrict pwc, const char *restrict s, size_t n )
(since C99)

Converts a multibyte character whose first byte is pointed to by s to a wide character, written to *pwc if pwc is not null.

If s is a null pointer, resets the global conversion state and determines whether shift sequences are used.

Contents

Notes

Each call to mbtowc updates the internal global conversion state (a static object of type mbstate_t, only known to this function). If the multibyte encoding uses shift states, care must be taken to avoid backtracking or multiple scans. In any case, multiple threads should not call mbtowc without synchronization: mbrtowc may be used instead.

Parameters

pwc - pointer to the wide character for output
s - pointer to the multibyte character
n - limit on the number of bytes in s that can be examined

Return value

If s is not a null pointer, returns the number of bytes that are contained in the multibyte character or -1 if the first bytes pointed to by s do not form a valid multibyte character or 0 if s is pointing at the null charcter '\0'.

If s is a null pointer, resets its internal conversion state to represent the initial shift state and returns 0 if the current multibyte encoding is not state-dependent (does not use shift sequences) or a non-zero value if the current multibyte encoding is state-dependent (uses shift sequences).

Example

See also

converts the next multibyte character to wide character, given state
(function) [edit]
returns the number of bytes in the next multibyte character
(function) [edit]