Difference between stdout and stderr

# Include "stdio. H"
# Include "unistd. H"

Int main ()
{
While (1)
{
Fprintf (stderr, "Hello-STD-Err ");
Fprintf (stdout, "Hello-STD-out ");
Sleep (1 );
}
Return 0;

}

Stderr is not a buffer. Stdout is the row buffer. So when you have strict real-time requirements on output information, use stderr.

Stdout standard output and stderr standard error output are output to the screen by default.

If the redirection is output to the disk file, stdout is output to the file, while stderr is still output to the screen. Stderr is displayed as a program running error.