diff --git a/include/functions b/include/functions
index 3b69544f..9be236a6 100644
--- a/include/functions
+++ b/include/functions
@@ -1383,7 +1383,7 @@
         SHORT=""
 
         # lxc environ detection
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             if [ -f /proc/1/environ ]; then
                 FIND=$(grep -qa 'container=lxc' /proc/1/environ 2> /dev/null)
                 if [ $? -eq 0 ]; then
@@ -1396,7 +1396,7 @@
         fi
 
         # facter
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             if [ -x /usr/bin/facter ] || [ -x /usr/local/bin/facter ]; then
                 case "$(facter is_virtual)" in
                 "true")
@@ -1415,11 +1415,11 @@
         fi
 
         # systemd
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             if [ -x /usr/bin/systemd-detect-virt ]; then
                 LogText "Test: trying to guess virtualization technology with systemd-detect-virt"
                 FIND=$(/usr/bin/systemd-detect-virt)
-                if [ ! "${FIND}" = "" ]; then
+                if [ ! -z "${FIND}" ]; then
                     LogText "Result: found ${FIND}"
                     SHORT="${FIND}"
                 fi
@@ -1432,11 +1432,11 @@
 
         # lscpu
         # Values: VMware
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             if [ -x /usr/bin/lscpu ]; then
                 LogText "Test: trying to guess virtualization with lscpu"
                 FIND=$(lscpu | grep -i "^Hypervisor Vendor" | awk -F: '{ print $2 }' | sed 's/ //g')
-                if [ ! "${FIND}" = "" ]; then
+                if [ ! -z "${FIND}" ]; then
                     LogText "Result: found ${FIND}"
                     SHORT="${FIND}"
                 else
@@ -1451,7 +1451,7 @@
 
         # dmidecode
         # Values: VMware Virtual Platform / VirtualBox
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             if [ -x /usr/bin/dmidecode ]; then DMIDECODE_BINARY="/usr/bin/dmidecode"
             elif [ -x /usr/sbin/dmidecode ]; then DMIDECODE_BINARY="/usr/sbin/dmidecode"
             else
@@ -1460,7 +1460,7 @@
             if [ ! "${DMIDECODE_BINARY}" = "" -a ${PRIVILEGED} -eq 1 ]; then
                 LogText "Test: trying to guess virtualization with dmidecode"
                 FIND=$(/usr/sbin/dmidecode -s system-product-name | awk '{ print $1 }')
-                if [ ! "${FIND}" = "" ]; then
+                if [ ! -z "${FIND}" ]; then
                     LogText "Result: found ${FIND}"
                     SHORT="${FIND}"
                 else
@@ -1477,28 +1477,25 @@
         # < needs snippet >
 
         # Try common guest processes
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             LogText "Test: trying to guess virtual machine type by running processes"
 
             # VMware
-                IsRunning vmware-guestd
-                if [ ${RUNNING} -eq 1 ]; then SHORT="vmware"; fi
-                IsRunning vmtoolsd
-                if [ ${RUNNING} -eq 1 ]; then SHORT="vmware"; fi
+            if IsRunning vmware-guestd; then SHORT="vmware"
+            elif IsRunning vmtoolsd; then SHORT="vmware"
+            fi
 
             # VirtualBox based on guest services
-                IsRunning vboxguest-service
-                if [ ${RUNNING} -eq 1 ]; then SHORT="virtualbox"; fi
-                IsRunning VBoxClient
-                if [ ${RUNNING} -eq 1 ]; then SHORT="virtualbox"; fi
-                IsRunning VBoxService
-                if [ ${RUNNING} -eq 1 ]; then SHORT="virtualbox"; fi
+            if IsRunning vboxguest-service; then SHORT="virtualbox"
+            elif IsRunning VBoxClient; then SHORT="virtualbox"
+            elif IsRunning VBoxService; then SHORT="virtualbox"
+            fi
         else
             LogText "Result: skipped processes test, as we already found platform"
         fi
 
         # Amazon EC2
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             LogText "Test: checking specific files for Amazon"
             if [ -f /etc/ec2_version -a -s /etc/ec2_version ]; then
                 SHORT="amazon-ec2"
@@ -1510,7 +1507,7 @@
         fi
 
         # sysctl values
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             LogText "Test: trying to guess virtual machine type by sysctl keys"
 
             # FreeBSD: hw.hv_vendor (remains empty for VirtualBox)
@@ -1525,7 +1522,7 @@
         fi
 
         # lshw
-        if [ "${SHORT}" = "" ]; then
+        if [ -z "${SHORT}" ]; then
             if [ ${PRIVILEGED} -eq 1 ]; then
                 if [ -x /usr/bin/lshw ]; then
                     LogText "Test: trying to guess virtualization with lshw"