pack函数不能打包超过5个字节

使用 Data::Dumper 查看变量包含哪些内容:

#!/usr/bin/perl
use strict;
use warnings;

use Data::Dumper;

my $A = "11:22:33:44:55:66";  # $a is a special variable, don't use it.
my @b = split /:/, $A;
warn Dumper \@b;

my @c = map hex, @b;
warn Dumper \@c;

my $d = pack 'H2' x 6, @c;
{   local $Data::Dumper::Useqq = 1;
    warn Dumper $d;
}


my @e = unpack 'H2' x 6, $d;
warn Dumper \@e;

for (@e) {
    printf("%02x:", $_);
}

输出:

$VAR1 = [
          '11',
          '22',
          '33',
          '44',
          '55',
          '66'
        ];
$VAR1 = [
          17,
          34,
          51,
          68,
          85,
          102
        ];
$VAR1 = "\0274Qh\205\20";
$VAR1 = [
          '17',
          '34',
          '51',
          '68',
          '85',
          '10'
        ];
11:22:33:44:55:0a:

值102太长,无法打包为H2,因此它被截断。你只得到 10 ,对应于 \20 八进制,即字符16,在十六进制中为10,再次解释为十六进制为 0a .

你可能认为 hex 将数字转换为十六进制,但它的作用正好相反。也许你最初想要这个?

#!/usr/bin/perl
use strict;
use warnings;

use Data::Dumper;

my $A = "11:22:33:44:55:66";
my @b = split /:/, $A;
warn Dumper \@b;

my @c = map sprintf('%02x', $_), @b;
warn Dumper \@c;

my $d = pack 'H2' x 6, @c;
{   local $Data::Dumper::Useqq = 1;
    warn Dumper $d;
}


my @e = unpack 'H2' x 6, $d;
warn Dumper \@e;

print hex, ':' for @e;