Fix issues found by shellcheck

Specifically: SC2268 (style): Avoid x-prefix in comparisons as it no longer serves a purpose.

Author: marmarek

archlinux/PKGBUILD.install

@@ -285,7 +285,7 @@ configure_systemd() {
     # fix / ro mounted
     ln -sf /usr/lib/systemd/system/systemd-remount-fs.service /etc/systemd/system/sysinit.target.wants/
 
-    if [ "x$changed" != "x" ]
+    if [ -n "$changed" ]
     then
         systemctl daemon-reload
     fi
@@ -442,7 +442,7 @@ post_remove() {
         changed=true
     fi
 
-    if [ "x$changed" != "x" ]
+    if [ -n "$changed" ]
     then
         systemctl daemon-reload
     fi

init/functions

@@ -118,7 +118,7 @@ umount_retry() {
 get_mac_from_iface() {
     local iface="$1"
     local mac=
-    if [ "x$iface" != "x" ] && [ -e "/sys/class/net/$iface" ]; then
+    if [ -n "$iface" ] && [ -e "/sys/class/net/$iface" ]; then
         mac="$(cat "/sys/class/net/$iface/address")"
     fi
     echo "$mac"
@@ -127,7 +127,7 @@ get_mac_from_iface() {
 get_iface_from_mac() {
     local mac="$1"
     local iface=
-    if [ "x$mac" != "x" ]; then
+    if [ -n "$mac" ]; then
         iface="$(ip -o link | grep -i "$mac" | awk '{print $2}' | cut -d ':' -f1)"
     fi
     echo "$iface"
@@ -144,7 +144,7 @@ get_qubes_managed_iface() {
     # Load the module explicitly here, to avoid waiting for udev doing that
     [ -e /sys/module/xen_netfront ] || modprobe xen-netfront || :
     qubes_iface="$(get_iface_from_mac "$mac")"
-    if [ "x$qubes_iface" != "x" ]; then
+    if [ -n "$qubes_iface" ]; then
         echo "$qubes_iface"
     elif [ -e /sys/class/net/eth0 ]; then
         echo eth0
@@ -159,7 +159,7 @@ get_prefix_from_subnet() {
     x=${1%%"$3"*}
     prefix=$(( $2 + (${#x}/4) ))
 
-    if [ "x$prefix" != "x" ]; then
+    if [ -n "$prefix" ]; then
         echo "$prefix"
     else
         echo "32"

vm-systemd/network-uplink-wait.sh

@@ -7,7 +7,7 @@
 # Setup IP address at specific time of system boot, instead of asynchronously
 # by udev
 QUBES_MANAGED_IFACE="$(get_qubes_managed_iface)"
-if [ "x$QUBES_MANAGED_IFACE" != "x" ]; then
+if [ -n "$QUBES_MANAGED_IFACE" ]; then
     # systemd does not support conditional After= dependencies, nor a tool to
     # just wait for the unit to be activated
     # if the network interface is expected, use `systemctl start` to wait for