in reply to Regex to match non image urls

In these cases it is generally easier to write a regexp which matches only image URLs, and then use the negative match operator !~ instead of the match operator =~.

if ($url !~ m{^.*(jpe?g|gif|xbm|png|bmp)$}) {
  say "$url is not an image";
}

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perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'

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Re^2: Regex to match non image urls
by userdefinable (Initiate) on Jan 18, 2013 at 09:23 UTC
    Thanks but I'm trying to get the instances of this out of a chunk of text though. Like this: 
    s~m(\[img\]\s*.*?\.(?:jpe?g|png|svg|gif|bmp)\s*\[/img\])x~Invalid~isg;

    [download]
    but it doesn't work, so I'm clearly not using it correctly.
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[d/l]

      Ah, OK. You never said it was part of a s/// operator.

      Maybe something along these lines?

      use 5.010;
use strict;
use warnings;
my $text = do { local $/ = <DATA> };

my ($start, $end) = map quotemeta, qw([img] [/img]);
$text =~ s{($start(.+?)$end)}{
    my $link = $1;
    my $uri  = $2;
    $uri =~ /\.(?:jpe?g|png|svg|gif|bmp)$/ ? $link : 'Invalid'
}eg;

print $text;

__DATA__
Foo
[img]http://example.com/[/img]
Bar
[img]http://example.com/logo.jpeg[/img]

      [download]

      That said, what you are doing is conceptually broken. It is perfectly valid for an image on the web to have a URL ending with ".cgi", ".php", or even ".html". Whether something is an image or not is decided by its HTTP Content-Type header, not by the last few characters of the URL.

      perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'
      /p
[reply]
[d/l]
[select]
        That said, what you are doing is conceptually broken. It is perfectly valid for an image on the web to have a URL ending with ".cgi", ".php", or even ".html". Whether something is an image or not is decided by its HTTP Content-Type header, not by the last few characters of the URL.

        I couldn't agree more, sir.

        That being said, I like the elegance of your code snippet.

[reply]

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