my $fh = myOpen( "<", $pathname )

##</code><code>##

my %cache;
sub myOpen {
    my( $mode, $path ) = @_;
    my $fh;
    if ( not exists $cache{ $path } ) {
        -s $path or return;    # don't do a 0-length or non-existent file
        open $fh, $mode, $path or return;
        ( sysread( $fh, $cache{ $path }, -s _ ) == -s _ ) or return;
        close $fh;
    }
    open $fh, $mode, \$cache{ $path } or return;
    return $fh;
}