diff --git a/check_smartarray.sh b/check_smartarray.sh
index 936592a..d2a0362 100644
--- a/check_smartarray.sh
+++ b/check_smartarray.sh
@@ -3,29 +3,29 @@
 # Written by: Søren Klintrup <github at klintrup.dk>
 # Get your copy from: https://github.com/Klintrup/check_smartarray/
 
+unset ERRORSTRING
+unset OKSTRING
+unset ERR
+
 PATH="/sbin:/bin:/usr/sbin:/usr/bin"
 if [ -x "/sbin/camcontrol" ]
 then
- DEVICES="$(camcontrol devlist|egrep "(HP|COMPAQ) RAID"|sed -Ee 's/.*(pass[0-9]{1,3}).*/\1/')"
+ DEVICES="$(camcontrol devlist|grep -Ee "(HP|COMPAQ) RAID"|sed -Ee 's/.*(pass[0-9]{1,3}).*/\1/')"
 else
  ERRORSTRING="camcontrol binary does not exist on system"
  ERR=3
 fi
 
-unset ERRORSTRING
-unset OKSTRING
-unset ERR
-
 for DEVICE in ${DEVICES}
 do
  DEVICENAME="$(camcontrol devlist|grep ${DEVICE}|sed -Ee 's/.*(da[0-9]{1,3}).*/\1/')"
  DEVICESTRING="$(camcontrol inquiry ${DEVICE} -D|sed -n -e 's/^[^<]*<\([^>]*\)>.*$/\1/p')"
- if [ "$(echo ${DEVICESTRING}|tr [:upper:] [:lower:]|sed -Ee 's/.*(rea|int|exp|rec|fai|ok).*/\1/')" = "" ]
+ if [ "$(echo ${DEVICESTRING}|tr '[:upper:]' '[:lower:]'|sed -Ee 's/.*(rea|int|exp|rec|fai|ok).*/\1/')" = "" ]
  then
   ERRORSTRING="${ERRORSTRING} / ${DEVICENAME}: unknown state"
   if ! [ "${ERR}" = 2 ];then ERR=3;fi
  else
-  case $(echo ${DEVICESTRING}|tr [:upper:] [:lower:]|sed -Ee 's/.*(rea|int|exp|rec|fai|ok).*/\1/') in
+  case $(echo ${DEVICESTRING}|tr '[:upper:]' '[:lower:]'|sed -Ee 's/.*(rea|int|exp|rec|fai|ok).*/\1/') in
    int)
     ERR=2
     ERRORSTRING="${ERRORSTRING} / ${DEVICENAME}: DEGRADED"
@@ -35,15 +35,15 @@ do
     ERRORSTRING="${ERRORSTRING} / ${DEVICENAME}: FAILED"
     ;;
    rec)
-    if ! [ "${ERR}" = 2 -o "${ERR}" = 3 ]; then ERR=1;fi
+    if ! [ "${ERR}" = 2 ] || [ "${ERR}" = 3 ]; then ERR=1;fi
     ERRORSTRING="${ERRORSTRING} / ${DEVICENAME}: rebuilding"
     ;;
    exp)
-    if ! [ "${ERR}" = 2 -o "${ERR}" = 3 ]; then ERR=1;fi
+    if ! [ "${ERR}" = 2 ] || [ "${ERR}" = 3 ]; then ERR=1;fi
     ERRORSTRING="${ERRORSTRING} / ${DEVICENAME}: expanding"
     ;;
    rea)
-    if ! [ "${ERR}" = 2 -o "${ERR}" = 3 ]; then ERR=1;fi
+    if ! [ "${ERR}" = 2 ] || [ "${ERR}" = 3 ]; then ERR=1;fi
     ERRORSTRING="${ERRORSTRING} / ${DEVICENAME}: ready for recovery"
     ;;
    ok)
@@ -57,10 +57,10 @@ if [ "${1}" ]
 then
  if [ "${ERRORSTRING}" ]
  then
-  echo "${ERRORSTRING} ${OKSTRING}"|sed s/"^\/ "//|mail -s "$(hostname -s): ${0} reports errors" -E ${*}
+  echo "${ERRORSTRING} ${OKSTRING}"|sed s/"^\/ "//|mail -s "$(hostname -s): ${0} reports errors" -E "${@}"
  fi
 else
-if [ "${ERRORSTRING}" -o "${OKSTRING}" ]
+if [ "${ERRORSTRING}" ] || [ "${OKSTRING}" ]
  then
   echo ${ERRORSTRING} ${OKSTRING}|sed s/"^\/ "//
   exit ${ERR}