comphash

#!/bin/bash

## Check md5 and sha1 hash
# https://www.dyclassroom.com/howto-mac/how-to-verify-checksum-on-a-mac-md5-sha1-sha256-etc
# http://osxdaily.com/2012/02/05/check-sha1-checksum-in-mac-os-x/
# http://osxdaily.com/2009/10/13/check-md5-hash-on-your-mac/
#When referring to a hexadecimal string output, it is case insensitive. A textual representation of binary data.
#http://en.wikipedia.org/wiki/Hexadecimal

###===============================================================##


compHash(){
  while true; do
  # read will take user input and assign it to variable - fileToCompare, correctHash
  read -e -r -p "Enter Path To File: " fileToCompare
  if [ ! -e "$fileToCompare" ] ; then
    echo -e "File Not Found. \n Enter Correct Filepath." >&2
  else
    break
  fi
done

while true; do
  read -e -r -p "Enter Files Correct Hash: " correctHash
  if [  -z "$correctHash" ] ; then
    echo -e "No Hash Value Entered." >&2
  else
    break
  fi
done

# Bash Menu Script
PS3='Select Hash comparison you need: '
options=("SHA-1" "SHA-256" "SHA-512" "md5" "Quit")
select opt in "${options[@]}"
do
  case $opt in
    "SHA-1")
      echo "Comparing SHA-1 values"
      hashOption=$(shasum -a 1 "$fileToCompare" | awk '{print $1}')
      break
      ;;
    "SHA-256")
      echo "Comparing SHA-256 values"
      hashOption=$(shasum -a 256 "$fileToCompare" | awk '{print $1}')
      break
      ;;
    "SHA-512")
      echo "Comparing SHA-512 values"
      hashOption=$(shasum -a 512 "$fileToCompare" | awk '{print $1}')
      break
      ;;
    "md5")
      echo "you chose choice $REPLY which is $opt"
      hashOption=$(md5 "$fileToCompare" | awk '{print $4}')
      break
      ;;
    "Quit")
      echo -e "\033[33;31m Comparison Aborted"
      exit 0
      ;;
    *) echo -e "\033[33;31m invalid option $REPLY";;
  esac
done

calculatedHash=$hashOption
#taking the user inputted correctHash and converts to lowercase in the event website displays the hash all in CAPs
lowerCaseHash=$(echo "$correctHash" | tr '[:upper:]' '[:lower:]')

if [[ "${calculatedHash}" == "${lowerCaseHash}" ]]; then
  echo -e "\033[33;32m The Hash looks good."
  echo -e "\033[33;32m Correct Hash:    $correctHash"
  echo -e "\033[33;32m Your files Hash: $calculatedHash"
else
  echo -e "\033[33;31m Uh Oh Hash does not match..." # RED \033[33;31m
  echo -e "\033[33;32m The Correct Hash: $correctHash" # GREEN \033[33;32m
  echo -e "\033[33;31m Your files Hash:  $calculatedHash"
fi

}


compHash "$@"


exit $?