diff --git a/contrib/isc-dhcp/client/scripts/freebsd b/contrib/isc-dhcp/client/scripts/freebsd
index 41bf9acbf2f7..571845b90086 100755
--- a/contrib/isc-dhcp/client/scripts/freebsd
+++ b/contrib/isc-dhcp/client/scripts/freebsd
@@ -9,9 +9,9 @@ else
 fi
 
 make_resolv_conf() {
-  echo search $new_domain_name >/etc/resolv.conf
-  for nameserver in $new_domain_name_servers; do
-    echo nameserver $nameserver >>/etc/resolv.conf
+  echo "search $new_domain_name" >/etc/resolv.conf
+  for nameserver in "$new_domain_name_servers"; do
+    echo "nameserver $nameserver" >>/etc/resolv.conf
   done
 }
 
@@ -36,140 +36,140 @@ if [ -x /etc/dhclient-enter-hooks ]; then
   fi
 fi
 
-if [ x$new_broadcast_address != x ]; then
+if [ "x$new_broadcast_address" != "x" ]; then
   new_broadcast_arg="broadcast $new_broadcast_address"
 fi
-if [ x$old_broadcast_address != x ]; then
+if [ "x$old_broadcast_address" != "x" ]; then
   old_broadcast_arg="broadcast $old_broadcast_address"
 fi
-if [ x$new_subnet_mask != x ]; then
+if [ "x$new_subnet_mask" != "x" ]; then
   new_netmask_arg="netmask $new_subnet_mask"
 fi
-if [ x$old_subnet_mask != x ]; then
+if [ "x$old_subnet_mask" != "x" ]; then
   old_netmask_arg="netmask $old_subnet_mask"
 fi
-if [ x$alias_subnet_mask != x ]; then
+if [ "x$alias_subnet_mask" != "x" ]; then
   alias_subnet_arg="netmask $alias_subnet_mask"
 fi
 
-if [ x$reason = xMEDIUM ]; then
-  ifconfig $interface $medium
-  ifconfig $interface inet -alias 0.0.0.0 $medium >/dev/null 2>&1
+if [ "x$reason" = "xMEDIUM" ]; then
+  ifconfig "$interface" "$medium"
+  ifconfig "$interface" inet -alias 0.0.0.0 "$medium" >/dev/null 2>&1
   sleep 1
   exit_with_hooks 0
 fi
 
-if [ x$reason = xPREINIT ]; then
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
+if [ "x$reason" = "xPREINIT" ]; then
+  if [ "x$alias_ip_address" != "x" ]; then
+    ifconfig "$interface" inet -alias "$alias_ip_address" > /dev/null 2>&1
+    route delete "$alias_ip_address" 127.0.0.1 > /dev/null 2>&1
   fi
-  ifconfig $interface inet 0.0.0.0 netmask 0.0.0.0 \
+  ifconfig "$interface" inet 0.0.0.0 netmask 0.0.0.0 \
 		broadcast 255.255.255.255 up
   exit_with_hooks 0
 fi
 
-if [ x$reason = xARPCHECK ] || [ x$reason = xARPSEND ]; then
+if [ "x$reason" = "xARPCHECK" ] || [ "x$reason" = "xARPSEND" ]; then
   exit_with_hooks 0;
 fi
   
-if [ x$reason = xBOUND ] || [ x$reason = xRENEW ] || \
-   [ x$reason = xREBIND ] || [ x$reason = xREBOOT ]; then
+if [ "x$reason" = "xBOUND" ] || [ "x$reason" = "xRENEW" ] || \
+   [ "x$reason" = "xREBIND" ] || [ "x$reason" = "xREBOOT" ]; then
   current_hostname=`/bin/hostname`
-  if [ x$current_hostname = x ] || \
-     [ x$current_hostname = x$old_host_name ]; then
-    if [ x$new_host_name != x$old_host_name ]; then
+  if [ "x$current_hostname" = "x" ] || \
+     [ "x$current_hostname" = "x$old_host_name" ]; then
+    if [ "x$new_host_name" != "x$old_host_name" ]; then
       $LOGGER "New Hostname: $new_host_name"
-      hostname $new_host_name
+      hostname "$new_host_name"
     fi
   fi
-  if [ x$old_ip_address != x ] && [ x$alias_ip_address != x ] && \
-		[ x$alias_ip_address != x$old_ip_address ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
+  if [ "x$old_ip_address" != "x" ] && [ "x$alias_ip_address" != "x" ] && \
+		[ "x$alias_ip_address" != "x$old_ip_address" ]; then
+    ifconfig "$interface" inet -alias "$alias_ip_address" > /dev/null 2>&1
+    route delete "$alias_ip_address" 127.0.0.1 > /dev/null 2>&1
   fi
-  if [ x$old_ip_address != x ] && [ x$old_ip_address != x$new_ip_address ]; then
-    ifconfig $interface inet -alias $old_ip_address $medium
-    route delete $old_ip_address 127.1 >/dev/null 2>&1
-    for router in $old_routers; do
-      route delete default $router >/dev/null 2>&1
+  if [ "x$old_ip_address" != "x" ] && [ "x$old_ip_address" != "x$new_ip_address" ]; then
+    ifconfig "$interface" inet -alias "$old_ip_address" "$medium"
+    route delete "$old_ip_address" 127.1 >/dev/null 2>&1
+    for router in "$old_routers"; do
+      route delete default "$router" >/dev/null 2>&1
     done
     if [ "$old_static_routes" != "" ]; then
       set $old_static_routes
       while [ $# -gt 1 ]; do
-	route delete $1 $2
+	route delete "$1" "$2"
 	shift; shift
       done
     fi
     arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' |sh
   fi
-  if [ x$old_ip_address = x ] || [ x$old_ip_address != x$new_ip_address ] || \
-     [ x$reason = xBOUND ] || [ x$reason = xREBOOT ]; then
-    ifconfig $interface inet $new_ip_address $new_netmask_arg \
-					$new_broadcast_arg $medium
+  if [ "x$old_ip_address" = "x" ] || [ "x$old_ip_address" != "x$new_ip_address" ] || \
+     [ "x$reason" = "xBOUND" ] || [ "x$reason" = "xREBOOT" ]; then
+    ifconfig "$interface" inet "$new_ip_address" "$new_netmask_arg" \
+					"$new_broadcast_arg" "$medium"
     $LOGGER "New IP Address($interface): $new_ip_address"
     $LOGGER "New Subnet Mask ($interface): $new_subnet_mask"
     $LOGGER "New Broadcast Address($interface): $new_broadcast_address"
     if [ "$new_routers" != "" ]; then
       $LOGGER "New Routers: $new_routers"
     fi
-    for router in $new_routers; do
-      route add default $router >/dev/null 2>&1
+    for router in "$new_routers"; do
+      route add default "$router" >/dev/null 2>&1
     done
     if [ "$new_static_routes" != "" ]; then
       $LOGGER "New Static Routes: $new_static_routes"
       set $new_static_routes
       while [ $# -gt 1 ]; do
-	route add $1 $2
+	route add "$1" "$2"
 	shift; shift
       done
     fi
   fi
-  if [ x$new_ip_address != x$alias_ip_address ] && [ x$alias_ip_address != x ];
+  if [ "x$new_ip_address" != "x$alias_ip_address" ] && [ "x$alias_ip_address" != "x" ];
    then
-    ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg
+    ifconfig "$interface" inet alias "$alias_ip_address" "$alias_subnet_arg"
   fi
-  echo search $new_domain_name >/etc/resolv.conf
-  for nameserver in $new_domain_name_servers; do
-    echo nameserver $nameserver >>/etc/resolv.conf
+  echo search "$new_domain_name" >/etc/resolv.conf
+  for nameserver in "$new_domain_name_servers"; do
+    echo nameserver "$nameserver" >>/etc/resolv.conf
   done
   exit_with_hooks 0
 fi
 
-if [ x$reason = xEXPIRE ] || [ x$reason = xFAIL ]; then
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
+if [ "x$reason" = "xEXPIRE" ] || [ "x$reason" = "xFAIL" ]; then
+  if [ "x$alias_ip_address" != "x" ]; then
+    ifconfig "$interface" inet -alias "$alias_ip_address" > /dev/null 2>&1
+    route delete "$alias_ip_address" 127.0.0.1 > /dev/null 2>&1
   fi
-  if [ x$old_ip_address != x ]; then
-    ifconfig $interface inet -alias $old_ip_address $medium
-    route delete $old_ip_address 127.1 >/dev/null 2>&1
-    for router in $old_routers; do
-      route delete default $router >/dev/null 2>&1
+  if [ "x$old_ip_address" != "x" ]; then
+    ifconfig "$interface" inet -alias "$old_ip_address" "$medium"
+    route delete "$old_ip_address" 127.1 >/dev/null 2>&1
+    for router in "$old_routers"; do
+      route delete default "$router" >/dev/null 2>&1
     done
     if [ "$old_static_routes" != "" ]; then
       set $old_static_routes
       while [ $# -gt 1 ]; do
-	route delete $1 $2
+	route delete "$1" "$2"
 	shift; shift
       done
     fi
     arp -n -a | sed -n -e 's/^.*(\(.*\)) at .*$/arp -n -d \1/p' \
 						|sh >/dev/null 2>&1
   fi
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg
+  if [ "x$alias_ip_address" != "x" ]; then
+    ifconfig "$interface" inet alias "$alias_ip_address" "$alias_subnet_arg"
   fi
   exit_with_hooks 0
 fi
 
-if [ x$reason = xTIMEOUT ]; then
-  if [ x$alias_ip_address != x ]; then
-    ifconfig $interface inet -alias $alias_ip_address > /dev/null 2>&1
-    route delete $alias_ip_address 127.0.0.1 > /dev/null 2>&1
+if [ "x$reason" = "xTIMEOUT" ]; then
+  if [ "x$alias_ip_address" != "x" ]; then
+    ifconfig "$interface" inet -alias "$alias_ip_address" > /dev/null 2>&1
+    route delete "$alias_ip_address" 127.0.0.1 > /dev/null 2>&1
   fi
-  ifconfig $interface inet $new_ip_address $new_netmask_arg \
-					$new_broadcast_arg $medium
+  ifconfig "$interface" inet "$new_ip_address" "$new_netmask_arg" \
+					"$new_broadcast_arg" "$medium"
   $LOGGER "New IP Address($interface): $new_ip_address"
   $LOGGER "New Subnet Mask($interface): $new_subnet_mask"
   $LOGGER "New Broadcast Address($interface): $new_broadcast_address"
@@ -177,22 +177,22 @@ if [ x$reason = xTIMEOUT ]; then
   if [ "$new_routers" != "" ]; then
     $LOGGER "New Routers: $new_routers"
     set $new_routers
-    if ping -q -c 1 $1; then
-      if [ x$new_ip_address != x$alias_ip_address ] && \
-			[ x$alias_ip_address != x ]; then
-	ifconfig $interface inet alias $alias_ip_address $alias_subnet_arg
+    if ping -q -c 1 "$1"; then
+      if [ "x$new_ip_address" != "x$alias_ip_address" ] && \
+			[ "x$alias_ip_address" != "x" ]; then
+	ifconfig "$interface" inet alias "$alias_ip_address" "$alias_subnet_arg"
       fi
-      for router in $new_routers; do
-	route add default $router >/dev/null 2>&1
+      for router in "$new_routers"; do
+	route add default "$router" >/dev/null 2>&1
       done
       set $new_static_routes
       while [ $# -gt 1 ]; do
-	route add $0 $1
+	route add "$0" "$1"
 	shift; shift
       done
-      echo search $new_domain_name >/etc/resolv.conf.std
-      for nameserver in $new_domain_name_servers; do
-	echo nameserver $nameserver >>/etc/resolv.conf.std
+      echo search "$new_domain_name" >/etc/resolv.conf.std
+      for nameserver in "$new_domain_name_servers"; do
+	echo nameserver "$nameserver" >>/etc/resolv.conf.std
       done
       if [ -f /etc/resolv.conf ]; then
 	rm -f /etc/resolv.conf
@@ -201,14 +201,14 @@ if [ x$reason = xTIMEOUT ]; then
       exit_with_hooks 0
     fi
   fi
-  ifconfig $interface inet -alias $new_ip_address $medium
-  for router in $old_routers; do
-    route delete default $router >/dev/null 2>&1
+  ifconfig "$interface" inet -alias "$new_ip_address" "$medium"
+  for router in "$old_routers"; do
+    route delete default "$router" >/dev/null 2>&1
   done
   if [ "$old_static_routes" != "" ]; then
     set $old_static_routes
     while [ $# -gt 1 ]; do
-      route delete $1 $2
+      route delete "$1" "$2"
       shift; shift
     done
   fi