external/bsd/dhcpcd/dist/dhcpcd-hooks/29-lookup-hostname

   1 # Lookup the hostname in DNS if not set
   2
   3 lookup_hostname()
   4 {
   5         [ -z "$new_ip_address" ] && return 1
   6         local h=
   7         # Silly ISC programs love to send error text to stdout
   8         if type dig >/dev/null 2>&1; then
   9                 h=$(dig +short -x $new_ip_address)
  10                 if [ $? = 0 ]; then
  11                         echo "$h" | sed 's/\.$//'
  12                         return 0
  13                 fi
  14         elif type host >/dev/null 2>&1; then
  15                 h=$(host $new_ip_address)
  16                 if [ $? = 0 ]; then
  17                         echo "$h" \
  18                         | sed 's/.* domain name pointer \(.*\)./\1/'
  19                         return 0
  20                 fi
  21         fi
  22         return 1
  23 }
  24
  25 set_hostname()
  26 {
  27         if [ -z "$new_host_name" -a -z "$new_fqdn_name" ]; then
  28                 export new_host_name="$(lookup_hostname)"
  29         fi
  30 }
  31
  32 case "$reason" in
  33 BOUND|INFORM|REBIND|REBOOT|RENEW|TIMEOUT|STATIC)        set_hostname;;
  34 esac