sub saveFilePos {
    my ($fileno, $filename) = @_;
    my $filepos = tell($fileno);
    open my $FH, '>', $filename or die "Can't open $fname: $!";
    print $FH $filepos;
    close $FH;
}

sub process {
    my $file = "/$ENV{HOME}/Error.log";
    my $file_last = "/$ENV{HOME}/Error.log.lastpos";
    my $file_pos = 0;   # Default to beginning of file
    eval {
        # Get last position in file (if any)
        open my $FH, '<', $file_last;
        if ($FH) {
            $file_pos = <$FH>;
            close $FH;
        }

        open ($tail,"<",$file_name) or die "Can't open file $file_name";
        seek($tail, $file_pos, 0);
        for(;;) {
            for $line (<$tail>) {
                if ( /OutOfMemoryError/) {
                    send_mail($_,$.);
                }
            }
        }

        # Save last position examined
        saveFilePos($tail, $file_last);
        close($tail);
    }
}