home *** CD-ROM | disk | FTP | other *** search
- #!/bin/sh
- if test "$1" = ""
- then
- echo usage: $0 domain
- exit 1
- fi
- DOMAIN=$1
- #
- # Use nslookup to discover the nameservers for this domain ($1).
- # Use awk to grab the name server names from the nameserver lines.
- # (The names are always in the last field). Use sort -u to weed out
- # duplicates; we don't actually care about collation.
- #
- SERVERS=`nslookup -type=ns $DOMAIN |\
- awk '/nameserver/ {print $NF}' | sort -u`
- if test "$SERVERS" = ""
- then
- #
- # Didn't find any servers. Just quit silently; nslookup will
- # have detected this error and printed a message. That will
- # suffice.
- #
- exit 1
- fi
- #
- # Check each server's SOA serial number. The output from
- # nslookup is saved in two tmp files: nso.$$ (standard output)
- # and nse.$$ (standard error). These files are rewritten on
- # every iteration. Turn off defname and search since we
- # should be dealing with fully qualified names.
- #
- # NOTE: this loop is rather long; don't be fooled.
- #
- for i in $SERVERS
- do
- nslookup >/tmp/nso.$$ 2>/tmp/nse.$$ <<-EOF
- server $i
- set nosearch
- set nodefname
- set norecurse
- set q=soa
- $DOMAIN
- EOF
- #
- # Does this response indicate that the current server ($i) is
- # authoritative? The server is NOT authoritative if (a) the
- # response says so, or (b) the response tells you to find
- # authoritative info elsewhere.
- #
- if egrep "Non-authoritative|Authoritative answers can be" \
- /tmp/nso.$$ >/dev/null
- then
- echo $i is not authoritative for $DOMAIN
- continue
- fi
- #
- # We know the server is authoritative; extract the serial number.
- #
- SERIAL=`cat /tmp/nso.$$ | grep serial | sed -e "s/.*= //"`
- if test "$SERIAL" = ""
- then
- #
- # We get here if SERIAL is null. In this case, there should
- # be an error message from nslookup; so cat the "standard
- # error" file.
- #
- cat /tmp/nse.$$
- else
- #
- # Report the server's name and its serial number.
- #
- echo $i has serial number $SERIAL
- fi
- done # end of the "for" loop
- #
- # Delete the temporary files.
- #
- rm -f /tmp/nso.$$ /tmp/nse.$$
-