Shell Programming and Scripting

echo -n "Record: "
    read rec
    echo -n "Author: "
    read author
    if grep -q "$rec:$author" "file.txt"; then
    echo -n "No. of copies sold: "
    read sold
    qtyA=`grep -w "$rec:$author" file.txt | cut -d: -f4`
    qtyS=`grep -w "$rec:$author" file.txt | cut -d: -f5`
    echo "Current Record info:"
    awk -F: -vOFS=", " -vt="$rec:$author" '$0~t{$3="$"$3;print}' file.txt
    echo "New Record info:"
    cQtyA=`expr $qtyA - $sold`
    cQtyS=`expr $qtyS + $sold`
    sed "s/$qtyA/$cQtyA/g" file.txt > file1.txt && mv file1.txt file.txt
    sed "s/$qtyS/$cQtyS/g" file.txt > file1.txt && mv file1.txt file.txt

    awk -F: -vOFS=", " -vt="$rec:$author" '$0~t{$3="$"$3;print}' file.txt
    else
    echo "Record not found!"
    fi