Use $(()) instead of $(expr)

1 files changed, 3 insertions, 3 deletions

diff --git a/certexpiry.sh b/certexpiry.sh
index ea2feeb..72ef8f8 100755
--- a/certexpiry.sh
+++ b/certexpiry.sh
@@ -59,14 +59,14 @@ while read HOSTANDPORT ; do
 #  echo "DEBUG: NOW: $NOW."
 
   # Number of seconds left
-  DIFFERENCE=$(expr "$EXPIRY" - "$NOW")
+  DIFFERENCE=$(("$EXPIRY" - "$NOW"))
 #  echo "DEBUG: DIFFERENCE: $DIFFERENCE."
 
   # Warn if less than WARNSECONDS less
   if [ "$DIFFERENCE" -lt "$WARNSECONDS" ] ; then
-    echo "Warning!  The certificate at $HOST:$PORT expires in $DIFFERENCE seconds (~$(expr $DIFFERENCE / 60 / 60 / 24) days)."
+    echo "Warning!  The certificate at $HOST:$PORT expires in $DIFFERENCE seconds (~$((DIFFERENCE / 60 / 60 / 24)) days)."
 #  else
-#    echo "DEBUG: The certificate at $HOST:$PORT expires in $DIFFERENCE seconds (~$(expr $DIFFERENCE / 60 / 60 / 24) days)."
+#    echo "DEBUG: The certificate at $HOST:$PORT expires in $DIFFERENCE seconds (~$((DIFFERENCE / 60 / 60 / 24)) days)."
   fi
 
 done < "$HOSTSANDPORTS"