6.23.6 btowc Function

Converts a character to an equivalent wide character.

Include

<wchar.h>

Prototype

wint_t btowc(int c);

Arguments

c

the character to convert

Return Value

The function returns the character c as wide character (type cast to type wint_t) provided that c is a valid single-byte character in the initial shift state of a multibyte sequence. Otherwise, or if c is EOF, the function returns WEOF.

Remarks

The function determines whether c constitutes a valid single-byte character in the initial shift state.

A multibyte character set may have a state-dependent encoding. Sequences begins in an initial shift state and enter other locale-specific shift states when specific multibyte characters are encountered. While in the initial shift state, all single-byte characters retain their usual interpretation and do not alter the shift state. The interpretation for subsequent bytes in the sequence is a function of the current shift state.

Example

See the notes at the beginning of this chapter or section for information on using printf() or scanf() (and other functions reading and writing the stdin or stdout streams) in the example code.

#include <wchar.h>

int main(void)
{
  int i, num = 0;
  const char mbs[] = "The quick brown fox\n";

  for(i=0; i!=sizeof(mbs); i++)
    if(btowc(mbs[i]) != WEOF)
      num++;

  wprintf(L"mbs contains %d single-byte characters.\n", num);
}

Example Output

mbs contains 21 single-byte characters.