fee-breakup

#!/bin/bash

# path to the file to read fee breakups from
breakupfile='/usr/share/deltaT1/feeBreakup.txt'


echo $(id -nu)

# Read the total amount from user
[[ -n $1 ]] && total_amount=$1 || { echo "Usage: feeBreakup total_amount"; exit 1; }

# Read feeBreakup.txt and generate arrays of
# category names and corresponding percentages

categories=()
percentages=()

n=0
readarray lines < "$breakupfile"
for entry in "${lines[@]}"; do

    IFS=' ' read -r -a words <<<"$entry"

    categories=(${categories[@]} ${words[0]})
    percentages=(${percentages[@]} ${words[1]%%'%'})

    ((n=n+1))

done

# Write to user's fees.txt

feesfile=$HOME/fees/fees.txt

echo $'\n'"Fee payment on $(date -Is)" >> "$feesfile"

# Iterate over categories, updating the cumulative
# amount and writing the transaction details at the
# same time
for ((i=0;i<n;i++)); do

    category=${categories[i]}

    # compute amount for i'th category
    # Bash does not support floating-point arithmetic.
    # Rather than require yet another utility to be
    # installed, we will simply disregard the decimal
    # point.
    amount=$(( $total_amount * ${percentages[i]} / 100 ))

    # Update cumulative amount
    oldamount=$(grep -m 1 "$category" "$feesfile" | grep -E -o '[0-9]+')
    newamount=$(($oldamount+$amount))
    sed -i "0,/${category}/ s/${category} ${oldamount}/${category} ${newamount}/" "$feesfile"

    # Write transaction details
    echo "${categories[i]} ${amount}" | tee -a "$feesfile"

done