nagios-nrpe: Improve readability for check_mount_rw

nagios-nrpe/files/plugins/check_mount_rw

@@ -1,30 +1,40 @@
 #!/bin/sh
+#
+# Verify that given mountpoints have 'read-write' option.
 
-output=$(mktemp --tmpdir $(basename $0).XXXXXXXXXX)
+output=$(mktemp --tmpdir $(basename "$0").XXXXXXXXXX)
 critical_count=0
 ok_count=0
 
 trap "rm -f $output" EXIT
 
 for mountpoint in $@; do
+    # We verify no mointpoints have 'read-only' option instead of checking
+    # for 'read-write' option, because there could be multiple device
+    # mounted on a sigle path.  In that edge case only checking for the
+    # presence of the 'read-write' option would yeild a flase positive.
     if findmnt -O ro --noheadings "$mountpoint" 1>/dev/null 2>&1; then
         echo "CRITICAL - $mountpoint" >> "$output"
-	critical_count=$(( critical_count + 1))
+        critical_count=$(( critical_count + 1))
     else
         echo "OK - $mountpoint" >> "$output"
-	ok_count=$(( ok_count + 1))
+        ok_count=$(( ok_count + 1))
     fi
 done
 
 total_count=$(( ok_count + critical_count ))
 
+plural=''
+test "$total_count" -gt 1 && plural='s'
+
 if [ $ok_count -eq  $total_count ]; then
-     printf "OK - %d/%d no read-only mountpoint\n\n" "$ok_count" "$total_count"
+     printf "OK - %d/%d  mountpoint%s have 'read-write' option\n\n" \
+         "$ok_count" "$total_count" "$plural"
      cat "$output"
      exit 0
 else
-    printf "CRITICAL - %d/%d read-only mountpoint\n\n" "$critical_count" "$total_count"
+    printf "CRITICAL - %d/%d mountpoint%s don't have 'read-write' option\n\n" \
+        "$critical_count" "$total_count" "$plural"
     cat "$output"
     exit 2 
 fi
-