如何使用perl脚本从文件中删除选中的重复行

open(my $file, '<', 'filename.txt') or die "Cannot open file: $!";

my %lines;
while (my $line = <$file>) {
    # 处理每一行内容
}

my %lines;
while (my $line = <$file>) {
    chomp $line;  # 去除行尾的换行符
    next if $lines{$line};  # 跳过重复行
    $lines{$line} = 1;  # 将行添加到哈希表中
    # 处理非重复行
}

open(my $output, '>', 'output.txt') or die "Cannot open file: $!";
foreach my $line (keys %lines) {
    print $output "$line\n";
}
close $output;

open(my $file, '<', 'filename.txt') or die "Cannot open file: $!";
my %lines;
while (my $line = <$file>) {
    chomp $line;
    next if $lines{$line};
    $lines{$line} = 1;
}
close $file;

open(my $output, '>', 'output.txt') or die "Cannot open file: $!";
foreach my $line (keys %lines) {
    print $output "$line\n";
}
close $output;