sub autoflush (*$) { 
# Set the state of autoflush for 
# the handle supplied as $_[0] 
# to the boolean state supplied as $_[1]
    select( 
        do{ 
            my $old = select( $_[0] ); 
            $| = $_[1]; 
            $old; 
        } 
    ) 
}
...
autoflush( STDOUT, 1 ); # autoflush on
...
autoflush( STDOUT, 0 ); # autoflush off