Thank you for replying. It has moved me forward a little. Upon using:

the variable then works in the if statement.

or

my $str = q{$line};
<p>gives</p>
 <code>(?^:</div></div><div><div class="blue"></div></div>
)
[download]

to the console, and

gives

(?^:</div></div>
)
[download]

You are right; I did get a warning before but misunderstood it. Now, adding r to the substition gives another warning:

 Useless use of non-destructive substitution (s///r) in void context at lr.pl line 76.

So I'm still in void context, which is bad, right? And I now have this

(?^:
)
[download]

to learn about. I also tried using

with

and writing to a separate file, which is getting warmer, actually removing some of the correct things, but leaving behind

(?^:</div></div>
)
[download]

I'm also still using print because say doesn't work for me; it asks for a package. If that little lot prompts no further clues to anyone I shall read on; thanks for your time on this.

my $remove = q{<div><div class="blue"></div></div>};

Don't use quoted string constructors to make regex patterns; use  qr// (update: to make honest-to-goodness regex objects) (see perlop, perlre, perlretut, and perlrequick). Using ordinary quoted string constructors sets you up for future puzzling bugs.

my $str = q{$line};

This is a meaningless statement; it just assigns a literal  $line to a string:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $str = q{$line};
 print qq{'$str'};
"
'$line'
[download]

my $str = qr{$line};

The problem here is that you seem to be trying to make the entire line you've just read from the file into a pattern. You then remove a piece of the pattern with a substitution:

c:\@Work\Perl\monks>perl -wMstrict -le
"my $remove = qr{ now \s+ brown }xms;
 ;;
 my $line = qq{how now brown cow \n};
 print qq{<$line>};
 ;;
 my $str = qr{$line};
 print $str;
 ;;
 ($line = $str) =~ s/$remove//;
 print qq{<$line>};
"
<how now brown cow
>
(?^:how now brown cow
)
<(?^:how  cow
)>
[download]

Do you see where the extraneous  (?^: ... ) stuff comes from?

Useless use of non-destructive substitution (s///r) in void context

You have to use a  s///r substitution in a statement like
    my $new_line_changed = $old_line_not_changed =~ s/$remove//gr;
(and I would recommend use of the  /g "global" modifier also).

Update: Changed variable names in last code example to (hopefully!) clarify the point being made.

---

Give a man a fish:  <%-{-{-{-<

Hi, I made an error in the second example I showed above (pointed out to me by ++Laurent_R). I'll correct it in my earlier post. I committed the copy-pasta sin :-(

When you compile a regexp using qr{} and then print it as a string, you get the output you showed here:

$ perl -wE 'my $x = qr{ foo }; say $x'
(?^u: foo )
[download]

But again, that was only output in your program because I had string and match reversed in my example.

say can be enabled with -E on the command line for one-liners, or with use feature 'say'; or use 5.010; in your program. It requires Perl 5.10 or newer.



The way forward always starts with a minimal test.