Writes a character to a specified file.
    Format
      #include  <stdio.h>
      int fputc  (int character, FILE *file_ptr);
1 – Arguments
 character
    An object of type int.
 file_ptr
    A file pointer.
2 – Description
    The fputc function writes a single character to the specified
    file and returns the character.
    Compiling with the __UNIX_PUTC macro defined enables an
    optimization that uses a faster, inlined version of this
    function.
    See also the fputc_unlocked function and the putc macro.
3 – Return Values
    x                  The character written to the file. Indicates
                       success.
    EOF                Indicates an output error.