Improve error report

.power_unique.sh

@@ -5,7 +5,18 @@ while IFS= read -r line; do
     echo $line >> $tmp
 done
 
+first_line=$(head -n1 $tmp|grep "timestamp,nsecs,power") # To check for validity
 last_line=$(cat $tmp | tail -n1)
+ncomma=$(echo "$last_line" | tr -cd ',' | wc -c | tr -d ' ') # To check for validity
+
+# Check if measurements are valid (not perfect test but sufficient)
+if [ -z "${first_line}" ] || [ $ncomma -ne 2 ]
+then
+    cat $tmp
+    exit 100
+fi
+
+# If valid then proceed to uniqueness
 cat $tmp | awk -F"," 'BEGIN{LAST=-1;skipped=0} {if(LAST!=$3){print $1","$2","$3;skipped=0}else{skipped=1} LAST=$3} END{if(skipped){print "'$last_line'"}}'
 rm $tmp