use strict;
my $str = 'http://....rech_cod_cat=1&rech_cod_rub=&rech_cod_typ=&rech_cod_sou_typ=&rech_cod_pay=TN&rech_cod_reg=&rech_cod_vil=&rech_cod_loc=&rech_prix_min=&rech_prix_max=&rech_surf_min=&rech_surf_max=&rech_age=&rech_photo=&rech_typ_cli=&rech_order_by=31&rech_page_num=829';
my $regex = qr/(\d+)$/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