Bash

#!/bin/sh 
 
if [ $# -lt 1 ]
then
    echo "usage: `basename $0` extension
Check domains avaliability
 
examples:
`basename $0` com
";
    exit 2;
fi
 
EXT=$1;
LAST_FILENAME=/tmp/dc_$USER$EXT.last
 
if [ -f "$LAST_FILENAME" ]; then LAST_DOMAIN=`cat $LAST_FILENAME`; fi 
 
for DOMAIN in {{0..9},{a..z},-}{{0..9},{a..z},-}{{0..9},{a..z},-}
do
    if [ "$DOMAIN" \< "$LAST_DOMAIN" ]; then continue; fi
 
    trap "echo $DOMAIN > $LAST_FILENAME;exit;" SIGHUP SIGINT SIGTERM
 
    STATUS_STRING=`wget -qO - http://www.whois.net/whois_new.cgi\?d\=$DOMAIN\&tld\=$EXT | grep 'Status'`
 
    echo "$STATUS_STRING" | grep 'free' && 
    echo "$DOMAIN.$EXT" >> ~/domains_found_$EXT.txt && 
    echo "the domain is free: $DOMAIN.$EXT" | mail -c my@mail.com -s "free domain" other@mail.com
 
    sleep 7
 
done