perl 關於排序功能

@a =qw(11 1 5 7 2);

@b = sort {$a<=>$b} @a;
print join ',',@b," ";

sort 排序 IP

use strict;
my @ip = ("140.21.135.218", "140.112.22.49", "140.213.21.4", "140.211.42.8");
my @order = sort ipsort @ip;   # 直接叫用副常式
print "$_ " for @order;
sub ipsort {
    my ($a1, $a2, $a3, $a4) = $a =~ /(\d+).(\d+).(\d+).(\d+)/;   # 分為四個數字
    my ($b1, $b2, $b3, $b4) = $b =~ /(\d+).(\d+).(\d+).(\d+)/;
    $a1 <=> $b1 or $a2 <=> $b2 or $a3 <=> $b3 or $a4 <=> $b4;   # 進行多子鍵排序
}

# ref: http://perl.hcchien.org/ch12.html