contrib/dhcpcd/hooks/29-lookup-hostname

   1 # Lookup the hostname in DNS if not set
   2
   3 lookup_hostname()
   4 {
   5         [ -z "$new_ip_address" ] && return 1
   6         # Silly ISC programs love to send error text to stdout
   7         if type dig >/dev/null 2>&1; then
   8                 h=$(dig +short -x $new_ip_address)
   9                 if [ $? = 0 ]; then
  10                         echo "$h" | sed 's/\.$//'
  11                         return 0
  12                 fi
  13         elif type host >/dev/null 2>&1; then
  14                 h=$(host $new_ip_address)
  15                 if [ $? = 0 ]; then
  16                         echo "$h" \
  17                         | sed 's/.* domain name pointer \(.*\)./\1/'
  18                         return 0
  19                 fi
  20         elif type getent >/dev/null 2>&1; then
  21                 h=$(getent hosts $new_ip_address)
  22                 if [ $? = 0 ]; then
  23                         echo "$h" | sed 's/[^ ]* *\([^ ]*\).*/\1/'
  24                         return 0
  25                  fi
  26         fi
  27         return 1
  28 }
  29
  30 set_hostname()
  31 {
  32         if [ -z "${new_host_name}${new_fqdn_name}" ]; then
  33                 export new_host_name="$(lookup_hostname)"
  34         fi
  35 }
  36
  37 if $if_up; then
  38         set_hostname
  39 fi