diff --git a/nixos-infect b/nixos-infect
index 1fa4201..622ec9f 100755
--- a/nixos-infect
+++ b/nixos-infect
@@ -39,17 +39,17 @@ EOF
   # XXX It'd be better if we used procfs for all this...
   local IFS=$'\n'
   eth0_name=$(ip address show | grep '^2:' | awk -F': ' '{print $2}')
-  eth0_ip4s=($(ip address show dev $eth0_name | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|'))
-  eth0_ip6s=($(ip address show dev $eth0_name | grep 'inet6 ' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|' || ''))
-  gateway=($(ip route show dev $eth0_name | grep default | sed -r 's|default via ([0-9.]+).*|\1|'))
-  ether0=($(ip address show dev $eth0_name | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|'))
+  eth0_ip4s=($(ip address show dev "$eth0_name" | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|'))
+  eth0_ip6s=($(ip address show dev "$eth0_name" | grep 'inet6 ' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|' || ''))
+  gateway=($(ip route show dev "$eth0_name" | grep default | sed -r 's|default via ([0-9.]+).*|\1|'))
+  ether0=($(ip address show dev "$eth0_name" | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|'))
 
   eth1_name=$(ip address show | grep '^3:' | awk -F': ' '{print $2}')||true
   if [ -n "$eth1_name" ];then
-    eth1_ip4s=($(ip address show dev $eth1_name | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|'))
-    eth1_ip6s=($(ip address show dev $eth1_name | grep 'inet6 ' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|' || ''))
-    ether1=($(ip address show dev $eth1_name | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|'))
-    gateway6=($(ip -6 route show dev $eth1_name | grep default | sed -r 's|default via ([0-9a-f:]+).*|\1|' || true))
+    eth1_ip4s=($(ip address show dev "$eth1_name" | grep 'inet ' | sed -r 's|.*inet ([0-9.]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|'))
+    eth1_ip6s=($(ip address show dev "$eth1_name" | grep 'inet6 ' | sed -r 's|.*inet6 ([0-9a-f:]+)/([0-9]+).*|{ address="\1"; prefixLength=\2; }|' || ''))
+    ether1=($(ip address show dev "$eth1_name" | grep link/ether | sed -r 's|.*link/ether ([0-9a-f:]+) .*|\1|'))
+    gateway6=($(ip -6 route show dev "$eth1_name" | grep default | sed -r 's|default via ([0-9a-f:]+).*|\1|' || true))
     interfaces1=<< EOF
       $eth1_name = {
         ip4 = [$(for a in "${eth1_ip4s[@]}"; do echo -n "
@@ -113,17 +113,17 @@ EOF
 makeSwap() {
   # TODO check currently available swapspace first
   swapFile=`mktemp /tmp/nixos-infect.XXXXX.swp`
-  dd if=/dev/zero of=$swapFile bs=1M count=$((1*1024))
-  chmod 0600 $swapFile
-  mkswap $swapFile
-  swapon -v $swapFile
+  dd if=/dev/zero "of=$swapFile" bs=1M count=$((1*1024))
+  chmod 0600 "$swapFile"
+  mkswap "$swapFile"
+  swapon -v "$swapFile"
 }
 
 removeSwap() {
     for swapFile in /tmp/nixos-infect.*.swp
     do
-        swapoff -v $swapFile
-        rm -vf $swapFile
+        swapoff -v "$swapFile"
+        rm -vf "$swapFile"
     done
 }