Fetch key value from string linux - linux

Question

I am doing:
dig #example.com hostname.example.com | grep ANSWER:
which return me following output
;; flags: qr aa rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0
How can I use pipe to get the count of answer in variable.
var=$(dig #example.com hostname.example.com | grep ANSWER:|....?...)

Answer 1

Use awk. You can then loop through the columns, find the one with ANSWER:, and print the next column after it.
var=$(dig #example.com hostname.example.com |
awk '/ANSWER/ { for (i = 1; i < NF-1; i++) if ($i == "ANSWER:") { print $(i+1); break } }'

Answer 2

You can use awk like this:
dig #8.8.8.8 www.example.com | awk '/ANSWER:/{print $2}' RS=,
The key here is to use , as the input record separator. Look how the input records appear to awk when using RS=,:
; <<>> DiG 9.10.3-P4-Ubuntu <<>> #8.8.8.8 www.example.com
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY
status: NOERROR
id: 49711
;; flags: qr rd ra ad; QUERY: 1
ANSWER: 1 <----- Look here! The ANSWER: is a separate record
AUTHORITY: 0
ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0
flags:; udp: 512
;; QUESTION SECTION:
;www.example.com. IN A
;; ANSWER SECTION:
www.example.com. 74953 IN A 93.184.216.34
;; Query time: 43 msec
;; SERVER: 8.8.8.8#53(8.8.8.8)
;; WHEN: Tue Jun 27 03:40:13 CEST 2017
;; MSG SIZE rcvd: 60
The ANSWER: N section is a separate record. Now we can simply filter the /ANSWER:/ record by regex and print the second column of that row using print $2.
PS: A sed alternative would be:
dig #8.8.8.8 www.example.com | sed -rn '/(.*ANSWER: )([0-9]+)(.*)/s//\2/p'