smartwatermelon

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

# Given a direction and a number of columns, write a function that outputs
# an arrow of asterisks

if [ $# -ne 2 ] || 
  ! ( ( [ $( echo $1 | tr [':upper:'] [':lower:'] ) == 'left' ] || [ $( echo $1 | tr [':upper:'] [':lower:'] ) == 'right' ] ) && [ -z "$(printf '%s\n' "$2" | sed 's/[0-9]//g')" ] ); then
  echo "$(basename $0): enter 'left' or 'right' and a positive integer, e.g. 'left 4' or 'right 3'"
  exit 1

smartwatermelon

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

# Imagine your users are all typing slightly incorrectly, in that they shifted their
# hands one key to the right. Write a function that translates what they mean to say. 

if [ $# -ne 1 ]; then
	echo "$(basename $0): enter a mis-typed string, e.g. ';p; epe'"
	exit 1
fi

smartwatermelon

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

# Given an IPv4 address and a netmask in CIDR notation, return a boolean
# specifying whether the IP address is inside the given range. 

# requirements:
# # bash version >= 4
# # 'grepcidr' command (http://www.pc-tools.net/unix/grepcidr/)

smartwatermelon

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

# Given a positive integer n, write a function that finds the number of zeros
# at the end of n! in base 10. 

if [ $# -eq 0 ] || [ -n "$(printf '%s\n' "$1" | sed 's/[0-9]//g')" ]; then
  echo "$(basename "$0"): enter a positive integer"
  exit 1
fi

smartwatermelon

#!/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)"

smartwatermelon

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

# Given a file named merry-christmas.txt that has a single integer x in it, write a script
# to generate a Christmas tree with asterisks (*) and output it as happy-holidays.txt. The
# tree should have a height of x, and if merry-christmas.txt is empty, the height should
# be 25 asterisks tall. 

IN_FILE="merry-christmas.txt"
OUT_FILE="happy-holidays.txt"

smartwatermelon

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

# return true if input is a perfect square
isPerfectSquare () {
  square_root=$( bc <<< "sqrt ($1)" )
  return $( [ $(( $square_root * $square_root )) == $1 ] )
}

smartwatermelon

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

# substitute asterisks for all but first and last characters of string
obscureString () {
	str="$1"
	ret="${str:0:1}$( printf "%0.s*" $( seq 1 $(( ${#str}-2 )) ) )${str: -1}"
	echo $ret
}

smartwatermelon

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

# initialize vars
runningTotal="0"

# normalized grade names to point values
A="4" AMINUS="3.7"
BPLUS="3.3" B="3" BMINUS="2.7"
CPLUS="2.3" C="2" CMINUS="1.7"

smartwatermelon

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

# initialize vars
ordinal=''

# check input
ARGC="$#" 
if [[ "$ARGC" -ne 1 ]]; then
	echo "Please enter an integer number, e.g. 123"