use strict;
my $str = 'https://www.youtube.com/watch?v=DFYRQ_zQ-gk&feature=featured
https://www.youtube.com/watch?v=DFYRQ_zQ-gk
http://www.youtube.com/watch?v=DFYRQ_zQ-gk
//www.youtube.com/watch?v=DFYRQ_zQ-gk
www.youtube.com/watch?v=DFYRQ_zQ-gk
https://youtube.com/watch?v=DFYRQ_zQ-gk
http://youtube.com/watch?v=DFYRQ_zQ-gk
//youtube.com/watch?v=DFYRQ_zQ-gk
youtube.com/watch?v=DFYRQ_zQ-gk
https://m.youtube.com/watch?v=DFYRQ_zQ-gk
http://m.youtube.com/watch?v=DFYRQ_zQ-gk
//m.youtube.com/watch?v=DFYRQ_zQ-gk
m.youtube.com/watch?v=DFYRQ_zQ-gk
https://www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
http://www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
//www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
www.youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
youtube.com/v/DFYRQ_zQ-gk?fs=1&hl=en_US
https://www.youtube.com/embed/DFYRQ_zQ-gk?autoplay=1
https://www.youtube.com/embed/DFYRQ_zQ-gk
http://www.youtube.com/embed/DFYRQ_zQ-gk
//www.youtube.com/embed/DFYRQ_zQ-gk
www.youtube.com/embed/DFYRQ_zQ-gk
https://youtube.com/embed/DFYRQ_zQ-gk
http://youtube.com/embed/DFYRQ_zQ-gk
//youtube.com/embed/DFYRQ_zQ-gk
youtube.com/embed/DFYRQ_zQ-gk
https://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk?autoplay=1
https://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
http://www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
//www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
www.youtube-nocookie.com/embed/DFYRQ_zQ-gk
https://youtube-nocookie.com/embed/DFYRQ_zQ-gk
http://youtube-nocookie.com/embed/DFYRQ_zQ-gk
//youtube-nocookie.com/embed/DFYRQ_zQ-gk
youtube-nocookie.com/embed/DFYRQ_zQ-gk
https://youtu.be/DFYRQ_zQ-gk?t=120
https://youtu.be/DFYRQ_zQ-gk
http://youtu.be/DFYRQ_zQ-gk
//youtu.be/DFYRQ_zQ-gk
youtu.be/DFYRQ_zQ-gk
https://www.youtube.com/HamdiKickProduction?v=DFYRQ_zQ-gk';
my $regex = qr/^((?:https?:)?\/\/)?((?:www|m)\.)?((?:youtube(-nocookie)?\.com|youtu.be))(\/(?:[\w\-]+\?v=|embed\/|v\/)?)([\w\-]+)(\S+)?$/imp;
if ( $str =~ /$regex/g ) {
print "Whole match is ${^MATCH} and its start/end positions can be obtained via \$-[0] and \$+[0]\n";
# print "Capture Group 1 is $1 and its start/end positions can be obtained via \$-[1] and \$+[1]\n";
# print "Capture Group 2 is $2 ... and so on\n";
}
# ${^POSTMATCH} and ${^PREMATCH} are also available with the use of '/p'
# Named capture groups can be called via $+{name}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html