SYNOPSISrblcheck [-qtlcvh?] [-s <service>] <address> [ <address> ... ]
rblcheck is a very basic interface to DNSBL listings such as those operated by The Spamhaus Project or Spamcop.
The general idea behind DNSBL listings is rapid lookup of IP addresses using DNS (for example, for blacklisting IP addresses because of abuse). Each IP address is reversed and has a domain name attached to it; for example, the IP address 127.0.0.2 would become 18.104.22.168, and then a domain such as "relays.visi.com" would be added to it. You would then try to resolve the result (ie. 22.214.171.124.relays.visi.com); if you receive a positive reply, then you know that the address is listed. Further information can also be queried, such as text descriptions of why the address was listed.
- Quiet mode; outputs only matching IP address(es) - use return code (see below).
- Print a TXT record, if any.
- Stop checking after first address match in any list.
- List default DNSBL services to check.
- Clear the current list of DNSBL services.
- -s <service>
- Toggle service in the DNSBL list.
- -h, -?
- Display the help message.
- Display version information.
An IP address to look up; specify `-' to read multiple addresses from
RETURN CODESWhen invoked, rblcheck returns either 0 (to indicate error, or that the address was not in any of the listings), or a positive number (indicating the number of listings that the IP address was found in).