Line counter dummy script

count-lines.sh

#!/bin/bash

EXTENSION=$1

FILE_COUNT=0
LINE_SUM=0
for FILE in $(find . -type f -iname "*.$EXTENSION")
do
    NUM_LINES=$(cat $FILE | wc -l)
    NUM_LINES=${NUM_LINES%% }
    NUM_LINES=${NUM_LINES## }

    LINE_SUM=$((LINE_SUM + $NUM_LINES))
    FILE_COUNT=$((FILE_COUNT + 1))
    echo "File $FILE has $NUM_LINES lines"
done

AVERAGE_LINE_PER_FILE=$(($LINE_SUM / $FILE_COUNT))
echo "Average line count is $AVERAGE_LINE_PER_FILE"