mbtowc
Remonter à Stdlib.h - Index
Header File
stdlib.h
Category
Conversion Routines, Memory and String Manipulation Routines
Prototype
int mbtowc(wchar_t *pwc, const char *s, size_t n);
Description
Converts a multibyte character to wchar_t code.
If s is not null, mbtowc determines the number of bytes that comprise the multibyte character pointed to by s. Next, mbtowc determines the value of the type wchar_t that corresponds to that multibyte character. If there is a successful match between wchar_t and the multibyte character, and pwc is not null, the wchar_t value is stored in the array pointed to by pwc. At most n characters are examined.
Return Value
When s points to an invalid multibyte character, -1 is returned. When s points to the null character, 0 is returned. Otherwise, mbtowc returns the number of bytes that comprise the converted multibyte character.
The return value never exceeds MB_CUR_MAX or the value of n.
Example
#include <stdlib.h>
#include<stdio.h>
void main(void)
{
int x;
char *mbchar = (char *)calloc(1, sizeof( char));
wchar_t wchar = L'a';
wchar_t *pwcnull = NULL;
wchar_t *pwchar = (wchar_t *)calloc(1, sizeof( wchar_t ));
printf ("Convert a wide character to multibyte character:\n");
x = wctomb( mbchar, wchar);
printf( "\tCharacters converted: %u\n", x);
printf( "\tMultibyte character: %x\n\n", mbchar);
printf ("Convert multibyte character back to a wide character:\n");
x = mbtowc( pwchar, mbchar, MB_CUR_MAX );
printf( "\tBytes converted: %u\n", x);
printf( "\tWide character: %x\n\n", pwchar);
printf ("Atempt to convert when target is NULL\n" );
printf (" returns the length of the multibyte character:\n" );
x = mbtowc (pwcnull, mbchar, MB_CUR_MAX );
printf ( "\tlength of multibyte character:%u\n\n", x );
printf ("Attempt to convert a NULL pointer to a" );
printf (" wide character:\n" );
mbchar = NULL;
x = mbtowc (pwchar, mbchar, MB_CUR_MAX);
printf( "\tBytes converted: %u\n", x );
}
Portability
POSIX | Win32 | ANSI C | ANSI C++ |
---|---|---|---|
+ |
+ |
+ |
+ |