Re^2: Strip specific html sequence

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

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

the variable then works in the if statement.

my $str = qr{$line};

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

to the console, and

( $line = $str ) =~ s/$remove//;

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

while (<$HTML>)

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.

Comment on Re^2: Strip specific html sequence Select or Download Code

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Re^3: Strip specific html sequence by AnomalousMonk (Archbishop) on Dec 10, 2017 at 18:15 UTC
`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: `<%-{-{-{-<`	[reply] [d/l] [select]
Re^3: Strip specific html sequence by 1nickt (Canon) on Dec 10, 2017 at 18:01 UTC
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.	[reply] [d/l] [select]