Perl regex无法匹配行尾

Question

我是Perl的新手。我正在尝试提取存储在文件中的VLAN信息。文件内容，

VLAN0001
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
PE8/1             Desg FWD 2         128.2945 P2p Edge 
Ta579               Desg FWD 3         128.5761 P2p Edge 

VLAN0023
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
PE8/1             Desg FWD 2         128.2945 P2p Edge 
Ta579               Desg FWD 3         128.5761 P2p Edge    

ACCOUNT
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Ta579               Desg FWD 1         128.5764 P2p

我有perl代码，

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;
my $filename = "spanning-tree1.txt";
    open my $fh, '<', $filename or die "error opening $filename: $!";
    my $data = do { local $/; <$fh> };

my @list = ($data =~ /(^[A-Za-z0-9]+.*?(?=^[A-Za-z0-9]+$|\Z))/msg);
#print Dumper($data);
#print "\n##############################################\n";
print Dumper(\@list);

它的输出是

$VAR1 = [
          'VLAN0001
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
PE8/1             Desg FWD 2         128.2945 P2p Edge
Ta579               Desg FWD 3         128.5761 P2p Edge

VLAN0023
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
PE8/1             Desg FWD 2         128.2945 P2p Edge
Ta579               Desg FWD 3         128.5761 P2p Edge

ACCOUNT
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Ta579               Desg FWD 1         128.5764 P2p'
        ];

我需要输出(@list)

$VAR1 = [
          'VLAN0001
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
PE8/1             Desg FWD 2         128.2945 P2p Edge
Ta579               Desg FWD 3         128.5761 P2p Edge

',
          'VLAN0023
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
PE8/1             Desg FWD 2         128.2945 P2p Edge
Ta579               Desg FWD 3         128.5761 P2p Edge

',
          'ACCOUNT
  Spanning tree enabled protocol rstp

Interface           Role Sts Cost      Prio.Nbr Type
------------------- ---- --- --------- -------- --------------------------------
Ta579               Desg FWD 1         128.5764 P2p'
        ];

有趣的是，我在@list 中得到了适当的值，当输入作为字符串给出，而不是从文件中读取。。

Answer 1

你可以用数字和大写字母在行的开头分割整串，

my @list = split /(?= ^[A-Z0-9]+\s*$ )/mx, do { local $/; <DATA> };

Answer 2

有时regex并不是唯一的解决方案：

#!/usr/bin/perl
use strict;
use warnings;
use Data::Dumper;

my $inc = -1;
my @list;

my $filename = "spanning-tree1.txt";
open my $fh, '<', $filename or die "error opening $filename: $!";

while (<$fh>) {
    /^[A-Z0-9]+\s*$/ and $inc++;
    $list[$inc] .= $_;
}
print Dumper(\@list);
close $fh;