This alternative uses File::Basename to extract the filename and the query string. It then uses the extension and parameter capturing portions of demerphq's regex (posted above) to extract the extension and strip the query string, if any. 
#!/usr/bin/perl

use File::Basename;
use strict;

my @files = (
    'http://server.com/subdir/index.html',
    'http://server.com/subdir/dist.tar.gz',
    'http://server.com/whatever.cgi?testing=1',
    'ftp://server.com/pub/whatever.zip',
    'file://local/subdir/testing.txt',
);


foreach my $file ( @files ){

    my $suffix = ( fileparse( $file, '\..*$' ) )[2];
    $suffix =~ s/(\.?[^.?]*)?\?.*?$/$1/;

    print $suffix, "\n";
}

[download]

Note that this code will not handle multi-level extensions, such as .tar.gz. The extension for dist.tar.gz will be reported as .gz (same deal with demerphq's code).

For extensions of this type, you'll probably need to create an array that's propagated with valid file extensions. Coincidentally, you can throw this array at File::Basename to easily ignore invalid extensions. Example:

my @valid_extensions = qw/ .tar.gz .html .zip /;

foreach my $file ( @files ){

    my $suffix = ( fileparse( $file, @valid_extensions ) )[2];

    print $suffix, "\n";
}

[download]
The above code will list a suffix only for the file types noted in @valid_extensions (not the txt or cgi files).

Jasmine

In reply to Re: Regex to match file extension in URL by Jazz
in thread Regex to match file extension in URL by Amoe

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