#!/bin/awk -f

BEGIN {
        print "Start";
        RS="Outgoing update query:"
        FS="\n"
}
{
        print "#### UPDATING CNAME ####"
        # Print what we are doing in clearer form
        split ($12, update, " ")
                print update[1],update[3],update[4],update[5]
        # Print the result of the operation on the DNS server
        if ($0 ~ /opcode/)
                split($0,array," ")
                if (array[6] == "NOERROR,")
                        sub(/,$/,"",array[6]);
                        print "OPERATION:",array[6];
        # If update failed lookup error
        if ($0 ~ "update failed:")
                split($(NF-1), error, " ")
                if (error[3] == "YXRRSET")
                        print "FAIL: CNAME already exist";
        else
                print "UPDATE SUCCEDED";
        print "\n"
}
END {
        print "Done"
}

Outgoing update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id:      0
;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
;; ZONE SECTION:
;exemple.local. IN   SOA

;; PREREQUISITE SECTION:
foo.exemple.local. 0 NONE A
foo.exemple.local. 0 NONE CNAME

;; UPDATE SECTION:
foo.exemple.local. 3600 IN CNAME realhost1.exemple.local.

Outgoing update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id:      0
;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
;; ZONE SECTION:
;exemple.local. IN   SOA

;; PREREQUISITE SECTION:
bar.exemple.local. 0 NONE A
bar.exemple.local. 0 NONE CNAME

;; UPDATE SECTION:
bar.exemple.local. 3600 IN CNAME realhost1.exemple.local.

Outgoing update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id:      0
;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
;; ZONE SECTION:
;exemple.local. IN   SOA

;; PREREQUISITE SECTION:
foo.exemple.local. 0 NONE A
foo.exemple.local. 0 NONE CNAME

;; UPDATE SECTION:
foo.exemple.local. 3600 IN CNAME realhost1.exemple.local.

update failed: YXRRSET
Outgoing update query:
;; ->>HEADER<<- opcode: UPDATE, status: NOERROR, id:      0
;; flags:; ZONE: 0, PREREQ: 0, UPDATE: 0, ADDITIONAL: 0
;; ZONE SECTION:
;exemple.local. IN   SOA

;; PREREQUISITE SECTION:
bar.exemple.local. 0 NONE A
bar.exemple.local. 0 NONE CNAME

;; UPDATE SECTION:
bar.exemple.local. 3600 IN CNAME realhost2.exemple.local.

update failed: YXRRSET

#### UPDATING CNAME ####
foo.exemple.local. IN CNAME realhost1.exemple.local.
OPERATION: NOERROR
UPDATE SUCCEDED

#### UPDATING CNAME ####
bar.exemple.local. IN CNAME realhost2.exemple.local.
OPERATION: NOERROR
FAIL: CNAME already exist