Win8 Strawberry 5.8.9.5 (32)  Tue 06/07/2022 12:17:53
C:\@Work\Perl\monks
>perl

use strict;
use warnings;

print '-\-\\-\\\-\\\\-\\\\\-\\\\\\-\\\\\\\-\\\\\\\\-';

^Z
-\-\-\\-\\-\\\-\\\-\\\\-\\\\-

##</code><code>##

Win8 Strawberry 5.8.9.5 (32)  Tue 06/07/2022 22:09:02
C:\@Work\Perl\monks
>perl

use strict;
use warnings;

my $h1 = 'A3f4';
my $h2 = 'xA3f4';

print hex 'A3f4',  "\n";
print hex $h1,     "\n";
print hex 'xA3f4', "\n";
print hex $h2,     "\n";

print hex '\xA3f4',   "\n";
print hex '\x{A3f4}', "\n";

^Z
41972
41972
41972
41972
Illegal hexadecimal digit '\' ignored at - line 13.
0
Illegal hexadecimal digit '\' ignored at - line 14.
0

##</code><code>##

Win8 Strawberry 5.8.9.5 (32)  Tue 06/07/2022 22:25:09
C:\@Work\Perl\monks
>perl

use strict;
use warnings;

my $str = '\x{aF}';

$str =~ m{ \A \\ x \{ ([[:xdigit:]]+) \} \z }xms;
my $hex_digits = $1;

print ">$hex_digits< \n";

my $hex_number_in_decimal = hex $hex_digits;
print "$hex_number_in_decimal \n";

^Z
>aF<
175

##</code><code>##

Win8 Strawberry 5.8.9.5 (32)  Sat 06/11/2022 15:18:47
C:\@Work\Perl\monks
>perl

use strict;
use warnings;

my $str = '\x{aF}';

my ($hex_digits) = $str =~ m{ [[:xdigit:]]+ }xmsg;
my $hex_number_in_decimal = hex $hex_digits;

print "'$hex_digits' == $hex_number_in_decimal decimal \n";

^Z
'aF' == 175 decimal