Place hostlookup anywhere in your path.  ~/bin is a good choice
for non-root users, /usr/local/bin or /usr/bin if you're root.

	Some different ways to feed addresses into hostlookup:

$ echo 199.245.105.1 206.228.67.167 | hostlookup
199.245.105.1   shell.dhp.com.
206.228.67.167  slartibartfast.pa.net.

$ hostlookup 199.245.105.1 206.228.67.167
199.245.105.1   shell.dhp.com.
206.228.67.167  slartibartfast.pa.net.

$ ( echo 199.245.105.1 ; echo 206.228.67.167 ) | hostlookup
199.245.105.1   shell.dhp.com.
206.228.67.167  slartibartfast.pa.net.

$ echo -e '199.245.105.1\n206.228.67.167' | hostlookup
199.245.105.1   shell.dhp.com.
206.228.67.167  slartibartfast.pa.net.

$ cat some_file_containing_IPs | hostlookup
...

$ hostlookup
{type in addresses interactively}

	The output is in /etc/hosts format, so you can add the addresses
to it easily.

	To do reverse lookups on an entire class B or C:
$ hostlookup 127.0.0.
	or
$ hostlookup 127.0.


	How to look up all non-rfc1918 addresses in /etc/hosts:

cat /etc/hosts | \
 sed -e 's/#.*//' | \
 grep -v '^10\.' | \
 grep -v '^192\.168\.' | \
 grep -v '^172\.1[6-9]' | \
 grep -v '^172\.2[0-9]' | \
 grep -v '^172\.3[01]' | \
 grep -v '^\W*$' | \
 awk '{print $1}' | \
 hostlookup

	To get the hostnames of all the people who've visted your web
site:

cat /var/log/httpd/*_log | awk '{print $1}' | uniq | sort | uniq | hostlookup >/var/log/httpd/all-web-hosts