Writes a character to the stdout stream.
#include <stdio.h> int putchar_unlocked ( int c);
(IN) Specifies the byte to be written.
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 putchar_unlocked function writes the character specified by the argument c to the output stream stdout.
The putchar_unlocked function is a non-thread safe version of the putchar function. It should be used in a multi-threaded program only if the invoking thread has locked stdout.