Writes a character to the output stream.
#include <stdio.h> int putc ( int c, FILE *fp);
(IN) Specifies the byte to be written.
(IN) Points to the file.
If successful, returns the character written. If a write error occurs, returns EOF, sets the error indicator for the stream, and sets errno to one of the following:
The putc function is equivalent to fputc, except that it can be implemented as a macro.