Perl XOR转义字符串，其中包含“ ^”

Question

How can I escape a "^" character when doing a bitwise XOR in Perl? My script is ok but when I input a string like .1M80P]/)S@*>RQF^RM< \\n then the output gets messed up:

#!/usr/bin/perl

$key = pack("H*","3cb37efae7f4f376ebbd76cd");

print "Enter string to decode: ";
$str=<STDIN>;chomp $str; $str =~s/\\(.)/$1/g;
$dec = decode($str);
print "Decoded string value: $dec\n";

sub decode{
    @subvar=@_;
    my $sqlstr = $subvar[0];
    $cipher = unpack("u", $sqlstr);
    $plain = $cipher^$key;
    return substr($plain, 0, length($cipher));
}

Output:

Enter string to decode: .1M80P]/)S@*>RQF^RM< \n
Decoded string value: zen94==tuvosÊ×

What is weird, the following string ,\\=_\\\\^M;+ D1F$U@7L\\n works ok and decodes as KL@OU4books! but again .;H ^F8B8EQ">SA^BDL8 \\n doesn't work as expected and gives back R3@coldfusioÆ

Here is the cleaned code by ikegami (same results though):

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

sub deliteral {
   my ($s) = @_;
   $s =~ s/\\n/\n/g;
   die "Unrecognised escape \\$1\n" if $s =~ /\\[a-zA-Z0-9]/;
   $s =~ s/\\(.)/$1/sg;
   return $s;   
}

sub uudecode {
   return unpack 'u', $_[0];
}

sub decode {
   my ($key, $cipher) = @_;
   return substr($cipher^$key, 0, length($cipher)); # XXX
}

my $key = pack('H*', '3cb37efae7f4f376ebbd76cd');

print "Enter string to decode: ";
chomp( my $coded = <STDIN> );

my $cipher = uudecode(deliteral($coded));
my $plain = decode($key, $cipher);
print("Plain text: $plain\n");

Answer 1

So this is the solution, thanks to ikegami help:

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

sub deliteral {
   my ($s) = @_;
   $s =~ s/\\n/\n/g;
   die "Unrecognised escape \\$1\n" if $s =~ /(?<!\\)(?:\\{2})*\\([a-zA-Z0-9])/;   $s =~ s/\\(.)/$1/sg;
   return $s;   
}

sub uudecode {
   return unpack 'u', $_[0];
}

sub decode {
   my ($key, $cipher) = @_;
   return substr($cipher^$key, 0, length($cipher)); # XXX
}

my $key = pack('H*', '3cb37efae7f4f376ebbd76cdfce7391e9ed9cee4cfceb4b33332fc96ff7b');

print "Enter string to decode: ";
chomp( my $coded = <STDIN> );

my $cipher = uudecode(deliteral($coded));
my $plain = decode($key, $cipher);
print("Plain text: $plain\n");

The problem was with the length of the KEY.