Use variable as RegEx pattern

Question

I\'d like to use a variable as a RegEx pattern for matching filenames:

my $file = \"test~\";
my $regex1 = \'^.+\\Q~\\E$\';
my $regex2 = \'^.+\\\\Q~\\\\E$\';
prin         


        

Answer 1

As documentation says:

    $re = qr/$pattern/;
    $string =~ /foo${re}bar/; # can be interpolated in other patterns
    $string =~ $re; # or used standalone
    $string =~ /$re/; # or this way

So, use the qr quote-like operator.

Answer 2

You cannot use \Q in a single-quoted / non-interpolated string. It must be seen by the lexer.

Anyway, tilde isn’t a meta-character.

Add use regex "debug" and you will see what is actually happening.