Perl比较两个文件并将行复制到新文件

Question

我是 perl 的初学者，我正在尝试用 perl 比较两个文件。一个包含 id 列表，另一个包含包含 id 和更多文本的字符串。我想将具有匹配 id 的行复制到第三个文件，但我只得到一个数字而不是正确的字符串。我做错了什么？

use strict;
use warnings;

open ( IDS , "<id.txt");
my @ids = <IDS>;
chomp(@ids);
close IDS;
my $id = @ids;
open ( META , "<meta.txt");
my @metas = <META>;
chomp(@metas);
my $meta = @metas;

open ( OUT1, ">>", "outtest.txt");
foreach $id (@metas){
    print OUT1 "$meta"."\n";
}
close OUT1;
close META;

Answer 1

尝试使用哈希变量获取输出：

use strict;
use warnings;

open ( META , "<meta.txt");
my %idsValues = (); #Create one new HASH Variable
while(<META>)
{
    my $line = $_;
    if($line=~m{<id>(\d+)</id>\s*<string>([^<>]*)</string>})
    {
        $idsValues{$1} = $2; #Store the values and text into the HASH Variable
    }
}
close(META); #Close the opened file
my @Values;
open ( IDS , "<id.txt");
while(<IDS>)
{
    my $line = $_;
    if($line=~m/<id>(\d+)<\/id>/i)
    {
    #Check if the value presents in the file and push them into ARRAY Variable.
        push(@Values, "IDS: $1\tVALUES: $idsValues{$1}") if(defined $idsValues{$1} );
    }
}
close(IDS); #Close the opened file
open ( OUT1, ">>", "outtest.txt");
print OUT1 join "\n", @Values; #Join with newline and Print the output line in the output file.
close OUT1; #Close the opened file