Hello Monks, I need some guidance. I am trying to write a little subroutine that takes before and after values and creates a substitution expression, so I can replace non-displayable characters in a file with displayable ones for example. However I cannot make this work with hex values; what I'm attempting looks like this (which replaces hex 'e9' with char '\x65'): 
my $pre = '\xe9';
my $post = '\x65';
my $re  = qr/s\/$pre\/$post\/g/;

my $path = 'C:\Scripts\Working2';
my $fileSep = "\\";
my $file = 'Users_0.xml';
my $tempFile = 'C:\Scripts\Working2\Users2.xml';

if (!open(IF, "<$path$fileSep$file")) {
    die("Could not open file $path$fileSep$file $!");
}
if (!open(OF, ">$tempFile")) {
    die("Could not open file $tempFile $!");
}    

while($str = <IF>) {
    $str =~ $re;
    print OF $str;
}
close IF;
close OF;

[download]
I know the substitution '$str =~ s/\xe9/\x65/g;' works just fine but parameterising it is the problem. Straightforward for char strings but seemingly less so for hex ones ... Can someone please advise?

In reply to Hex-matching Regex pattern in scalar by CliffG

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