How to fetch IP address from a log file? - awk

Question

I am trying to split the IP address into columns, I am new to this and have no idea where to start, hope you can give me a bit of an insight.
My log file
crawl-66-249-64-13.googlebot.com - - [17/Oct/2004:04:40:15 +0100] "GET /robots.txt HTTP/1.0" 200 25 "-" "Googlebot/2.1 (+http://www.google.com/bot.html)"
66-194-6-72.gen.twtelecom.net - - [17/Oct/2004:04:50:06 +0100] "GET / HTTP/1.1" 200 1727 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1; Q312460)"
dup-200-66-220-217.prodigy.net.mx - - [17/Oct/2004:05:36:43 +0100] "GET /midi/main_p.htm HTTP/1.1" 200 1061 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
dup-200-66-220-217.prodigy.net.mx - - [17/Oct/2004:05:37:08 +0100] "GET /favicon.ico HTTP/1.1" 404 1154 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
dup-200-66-220-217.prodigy.net.mx - - [17/Oct/2004:05:37:17 +0100] "GET /midi/mt_pcmid.htm HTTP/1.1" 200 1839 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
dup-200-66-220-217.prodigy.net.mx - - [17/Oct/2004:05:37:24 +0100] "GET /midi/mt_midcp.htm HTTP/1.1" 200 884 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
dup-200-66-220-217.prodigy.net.mx - - [17/Oct/2004:05:37:32 +0100] "GET /midi/mt_mpc.htm HTTP/1.1" 200 3321 "-" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.1)"
How to I display only the IP address?

Answer 1

Try this (using substitution and capturing groups) :
gawk '{
print gensub(/[^0-9]*([0-9]{1,3})-([0-9]{1,3})-([0-9]{1,3})-([0-9]{1,3}).*/,
"\\1.\\2.\\3.\\4",
"g",
$0)
}' file.txt
Another approach by DNS resolution :
cut -d' ' -f1 file.txt | xargs dig +short
or with awk :
awk '{print $1}' file.txt | xargs dig +short

Answer 2

You could also use grep and tr:
grep -Eo '([0-9]+-){3}[0-9]+' infile | tr - .
Output:
66.249.64.13
66.194.6.72
200.66.220.217
200.66.220.217
200.66.220.217
200.66.220.217
200.66.220.217

Answer 3

perl -lne 'm/(\d+-\d+-\d+-\d+)\./;$a=$1;$a=~s/-/\./g;print $a' your_file
tested:
> perl -lne 'm/(\d+-\d+-\d+-\d+)\./;$a=$1;$a=~s/-/\./g;print $a' temp
66.249.64.13
66.194.6.72
200.66.220.217
200.66.220.217
200.66.220.217
200.66.220.217
200.66.220.217