check_domain.pl

if ($whois =~ m/expir.*?((# dd-Mon-yy
d{2}-w{3}-(d{4}|d{2})|
#Jul 11 23:59:59 GMT 2013
w{3}sw{3}sd{2}sd{2}:d{2}:d{2}sw{3}sd{4}|
# dd Mon yyyy
d{2}sw{3}sd{4}|
# yyyy-mm-dd
d{4}-w{2}-d{2}))/xi or
$whois =~ m/status:.*OK-UNTILs((d{8}))d{6}/xi or
$whois =~ m/paid-till.*?((d{4}.d{2}.d{2}))/xi
) {
$edate = $1;
}
else {
print "Unknown - $domain expiration date not found.
";
exit 3;
}

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