use strict;
my $str = 'http://127.0.0.1:5000/x
http://127.0.0.1:5000/countries?
http://127.0.0.1:5000/countries?x
http://127.0.0.1:5000/countries?=
http://127.0.0.1:5000/countries?x=
http://127.0.0.1:5000/countries&
http://127.0.0.1:5000/countries&x
http://127.0.0.1:5000/countries&=
http://127.0.0.1:5000/countries&x=
http://127.0.0.1:5000/countries&x=x
http://127.0.0.1:5000/countries?code=AU?
http://127.0.0.1:5000/countries?name=Australia?x
http://127.0.0.1:5000/countries?name=Australia?=
http://127.0.0.1:5000/countries?name=Australia?x=
http://127.0.0.1:5000/countries?name=Australia?x=x
http://127.0.0.1:5000/countries?name=Australia&
http://127.0.0.1:5000/countries?name=Australia&x
http://127.0.0.1:5000/countries?name=Australia&=
http://127.0.0.1:5000/countries?name=Australia&x=
http://127.0.0.1:5000/countries
http://127.0.0.1:5000/countries?name=Australia
http://127.0.0.1:5000/countries?code=AU&name=Australia
http://127.0.0.1:5000/countries?name=New Zealand&calling_code=64
http://127.0.0.1:5000/countries?code=AU&name=Australia&capital=Canberra';
my $regex = qr/^http://127\.0\.0\.1:5000/countries(?:\?\w+=[\s\w]+(?:&\w+=[\s\w]+)*)?$/mp;
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