Perl 正则分组

[oracle@jhoa perl2]$ cat a1.pl    open(CPU,"<","/home/oracle/perl2/a1");    while (<CPU>) {       chomp;       if( /^model name.*: (.*$)/) {          $cpu_number += 1;          print "\$cpu_number is $cpu_number\n";          print "\$1 is $1\n";          $cpu_model="$1";          $cpu_model =~ s/\s+/ /g;       }    }[oracle@jhoa perl2]$ cat a1model name:         Intel(R) Core(TM) i3-2100 CPU @ 3.10GHz model name xxxxxxxxx$aaa="1234,5677,3333";$aaa=~/\d+,(\d+),\d+/;    #现在$1中就是5677print $1."\n";$bbb="2223,4241,45452";$bbb=~/(\d+),\d+,\d+/; #现在$1中是2223print $1;根据()括号 判断[oracle@jhoa perl2]$ cat a2.pl $aaa="1234,5677,3333";$aaa=~/\d+,(\d+),\d+/;    #现在$1中就是5677print $1."\n";$bbb="2223,4241,45452,24242";$bbb=~/(\d+),\d+,\d+,(\d+)/; #现在$1中是2223print $1, $2;[oracle@jhoa perl2]$ perl a2.pl 5677222324242[oracle@jhoa perl2]$