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Index for Section 3 |
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Alphabetical listing for M |
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mbstowcs(3)
NAME
mbstowcs, mbsrtowcs - Converts a multibyte character string to a wide-
character string
LIBRARY
Standard C Library (libc.so, libc.a)
SYNOPSIS
#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 );
STANDARDS
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.
PARAMETERS
*pwcs
Points to the array where the result of the conversion is stored.
*s or **s
Points or indirectly points to the multibyte-character string to be
converted.
n Specifies the number of wide characters in the destination array.
*ps Points to an mbstate_t structure containing the conversion state of the
data in s.
DESCRIPTION
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.
RESTRICTIONS
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.
RETURN VALUES
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.)
ERRORS
If the following condition occurs, the mbstowcs() and mbsrtowcs() functions
set errno to the corresponding value:
[EILSEQ]
The s parameter contains an invalid multibyte character.
RELATED INFORMATION
Functions: btowc(3), mblen(3), mbsinit(3), mbtowc(3), wcstombs(3),
wcslen(3), wctob(3), wctomb(3)