Determines if a wide character corresponds to a single-
    byte multibyte character and returns its multibyte character
    representation.
    Format
      #include  <stdio.h>
      #include  <wchar.h>
      int wctob  (wint_t c);
1 – Argument
 c
    The wide character to be converted to a single-byte multibyte
    character.
2 – Description
    The wctob function determines whether the specified wide
    character corresponds to a single-byte multibyte character when
    in the initial shift state and, if so, returns its multibyte
    character representation.
3 – Return Values
    x                  The single-byte representation of the wide
                       character specified.
    EOF                Indicates an error. The wide character
                       specified does not correspond to a single-byte
                       multibyte character.