@cassidoo's interview question from December 5, 2021

wrap.sh

#!/usr/bin/env bash
set -eu -o pipefail

# You have to order wrapping paper for presents. Given the length, width, and height of
# the boxes you need to wrap, return the number of square feet (or whatever units you
# want) of wrapping paper you need to order. Extra credit: allow for other shapes of
# presents and their dimensions! 

if [ $# -ne 3 ]; then
  echo "$(basename $0): enter three nonzero positive integers (length, width, depth)"
  exit 1
fi
for arg in "$@"; do
  if ! [[ $arg =~ ^[1-9]+$ ]]; then
    echo "$(basename $0): not a nonzero positive integer: $arg"
    exit 1
  fi
done

SURFACE=$(( ( 2 * $1 * $2 ) + ( 2 * $1 * $3 ) + ( 2 * $2 * $3 ) ))
echo "You'll need at least $SURFACE square units of wrapping paper"

MONTASIO:scripts andrewrich$ ./wrap.sh 
wrap.sh: enter three nonzero positive integers (length, width, depth)
MONTASIO:scripts andrewrich$ ./wrap.sh 5 6 7
You'll need at least 214 square units of wrapping paper
MONTASIO:scripts andrewrich$ ./wrap.sh 2 4 6
You'll need at least 88 square units of wrapping paper
MONTASIO:scripts andrewrich$ ./wrap.sh f 5 h
wrap.sh: not a nonzero positive integer: f