Initial data commit

Task/CSV-data-manipulation/UNIX-Shell/csv-data-manipulation-3.sh

@@ -0,0 +1,20 @@
+bash>exec 0<"$1"                 # open the input file on stdin
+exec 1>"$1.new"             # open an output file on stdout
+{
+    read -r header
+    echo "$header,SUM"
+    IFS=,
+    while read -r -a numbers; do
+        sum=0
+        for num in "${numbers[@]}"; do
+            (( sum += num ))
+        done
+
+        # can write the above loop as
+        #   sum=$(( $(IFS=+; echo "${numbers[*]}") ))
+
+        echo "${numbers[*]},$sum"
+    done
+} &&
+mv "$1" "$1.bak" &&
+mv "$1.new" "$1"