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mbstowcs, mbsrtowcs - Converts a multibyte character string to a wide-character string
Standard C Library (libc.so, libc.a)
#include <stdlib.h>
size_t mbstowcs(
wchar_t *pwcs,
const char *s,
size_t n);
#include <wchar.h>
size_t mbsrtowcs(
wchar_t *pwcs,
const char **s,
size_t n,
mbstate_t *ps );
Interfaces documented on this reference page conform to industry standards as follows:
mbstowcs(): ISO C, XPG4
mbsrtowcs(): ISO C
Refer to the standards(5) reference page for more information about industry standards and associated tags.
Points to the array where the result of the conversion is stored. Points or indirectly points to the multibyte-character string to be converted. Specifies the number of wide characters in the destination array. Points to an mbstate_t structure containing the conversion state of the data in s.
The mbstowcs() function converts a multibyte-character string into a wide-character string, which is stored at a specified location. The function does not examine or convert any characters that follow a null byte, which is converted and stored as a wide-character code with value zero. The function does not store more than n wide characters in pwcs. When operating on overlapping strings, the behavior of this function is undefined.
Behavior of the mbstowcs() function is affected by the LC_CTYPE category of the current locale. In locales that use shift-state encoding, the array pointed to by the s parameter begins in the initial shift state.
The mbsrtowcs() function is a restartable version of mbstowcs(). Restartable conversion functions obtain and store the conversion state in an mbstate_t structure that can be read and changed by subsequent calls to the same or other restartable conversion functions.
The mbsrtowcs() and other restartable versions of conversion functions are functional only when used with locales that support shift-state encoding. Currently, the Tru64 UNIX product does not provide any locales that support shift-state encoding, so the mbstowcs() and mbsrtowcs() functions do not differ in terms of run-time behavior.
When the mbstowcs() and mbsrtowcs() functions encounter an invalid multibyte character during conversion, they return a value of -1 cast to size_t and set errno to indicate the error. Otherwise, these functions return the number of wide characters stored in the output array, not including a terminating null wide character. (When the return value is n, the output array is not null-terminated.)
If the following condition occurs, the mbstowcs() and mbsrtowcs() functions set errno to the corresponding value: The s parameter contains an invalid multibyte character.
Functions: btowc(3), mblen(3), mbsinit(3), mbtowc(3), wcstombs(3), wcslen(3), wctob(3), wctomb(3) delim off