How to take the data between two strings in a file Linux

Question

I want to get the lines between forwarders { and }; those are IP address, below is the sample file which mimics my data..

// Red Hat BIND Configuration Tool
//
// THIS IS THE SLAVE DDNS SERVER -
//

// Currently running in chroot environment
// Prefix all file names below with /var/named/chroot
options {
        directory "/var/named";
        dump-file "/var/named/data/cache_dump.db";
        statistics-file "/var/named/data/named_stats.txt";
        recursion yes;
        check-names master ignore;
        check-names slave ignore;
        check-names respocope ignore;
        max-journal-size 2M;
        allow-query { any; };
        allow-update {
                key copdcop1.example.com.;
                key copdcop2.example.com.;
                key copdcop3.example.com.;
                key copdcop4.example.com.;
        };

        forward only;
        forwarders {
      192.168.174.131;     // cop-no1
      192.155.98.74;        // cop-jn1
      192.168.2.40;       // cop-sad1
      192.168.2.56;       // cop-s1
      192.43.4.70;        // cop-che1
      192.20.28.8;      // copdcop1
        };

Desired Result:

      192.168.174.131;     // cop-no1
      192.155.98.74;        // cop-jn1
      192.168.2.40;       // cop-sad1
      192.168.2.56;       // cop-s1
      192.43.4.70;        // cop-che1
      192.20.28.8;      // copdcop1

I'm okay with any solution either shell or python or awk.

I tried with sed but no luck..

sed -n '"/forwarders {"/,/"};"' dns.txt

However, below awk code works ..

awk '/forwarders {/{flag=1;next}/};/{flag=0}flag' dns.txt

Answer 1

EDIT: Since OP asked to have output into single line so adding following solution now.

awk 'BEGIN{OFS=","} /}/{found=""} /forwarders {/{found=1} found && match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/){gsub(/ +/," ");val=(val?val OFS:"")$0}END{print val}'  Input_file

OR non-one liner form of solution.

awk '
BEGIN{
  OFS=","
}
/}/{
  found=""
}
/forwarders {/{
  found=1
}
found && match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/){
  gsub(/ +/," ")
  val=(val?val OFS:"")$0
}
END{
  print val
}'  Input_file

OR as mentioned before too, to print anything inside forwarder block try:

awk '/}/{found=""} /forwarders {/{found=1;next} found{gsub(/ +/," ");val=(val?val OFS:"")$0} END{print val}'  Input_file

---

---

Could you please try following(considering that you only need to print IP addresses inside the tag).

awk '/}/{found=""} /forwarders {/{found=1} found && match($0,/[0-9]+\.[0-9]+\.[0-9]+\.[0-9]+/)'  Input_file

In case forwarders tag you want to anything then try following.

awk '/}/{found=""} /forwarders {/{found=1;next} found'  Input_file