wctob() — Convert wide character to byte

Standards

Standards / Extensions	C or C++	Dependencies
ISO C Amendment C99 Single UNIX Specification, Version 3	both

Format

Non-XPG4:

#include <wchar.h>

int wctob(wint_t c);

XPG4:

#define _XOPEN_SOURCE
#define _MSE_PROTOS
#include <wchar.h>

int wctob(wint_t c);

General description

Determines whether c corresponds to a member of the extended character set whose multibyte character corresponds to a single byte when in initial shift state.

The behavior of this wide-character function is affected by the LC_CTYPE category of the current locale. If you change the category, undefined results can occur.

Special behavior for XPG4: If you define any feature test macro specifying XPG4 behavior before the statement in your program source file to include the wchar header, then you must also define the _MSE_PROTOS feature test macro to make the declaration of the wctob() function in the wchar header available when you compile your program. Please see Table 1 for a list of XPG4 and other feature test macros.

Returned value

If successful, wctob() returns the single-byte representation.

If c does not correspond to a multibyte character with length one, wctob() returns EOF.

Example

CELEBW29

⁄* CELEBW29 *⁄                                   
#include <stdio.h>                                                              
#include <wchar.h>                                                              
                                                                                
int main(void)                                                                  
{                                                                               
   wint_t wc = L'A';                                                            
                                                                                
   if (wctob(wc) == wc)                                                         
      printf("wc is a valid single byte character\n");                          
   else                                                                         
      printf("wc is not a valid single byte character\n");                      
}

Output:

wc is a valid single-byte character

Related information

wchar.h