utilities.sh

# Define some common utility functions that are used by other scripts here.


# The maximum amount of seconds to wait in a loop.
MAXIMUM_WAIT_SECONDS=3600

# Download requires the url and the output directory or name.
function download() {
  local url=$1
  local destination=$2
  echo "Downloading ${url}"
  # -f fail silently
  # -L Follow location redirects
  # --retry three times
  # -o write output to a file
  curl -f -L --retry 3 ${url} -o ${destination}
  # Print out the size and sha256 hash sum of the archive.
  echo "$(ls -hl ${destination} | cut -d ' ' -f 5) $(basename ${destination})"
  echo "$(sha256sum_file ${destination}) $(basename ${destination})"
}

# The check_time function requires two parameters start_time and max_seconds.
function check_time() {
  local start_time=$1
  local maximum_seconds=$2
  local current_time=`date +"%s"`
  local difference=$(expr ${current_time} - ${start_time})
  # When the difference is greater than maximum seconds, exit this script.
  if [ ${difference} -gt ${maximum_seconds} ]; then
    echo "The process is taking more than ${maximum_seconds} seconds!"
    # End this script because too much time has passed.
    exit 3
  fi
}

# Run a command in a loop waiting for specific output use MAXIMUM_WAIT_SECONDS.
function run_and_wait() {
  local cmd=$1
  local match=$2
  local sleep_seconds=${3:-5}
  local start_time=`date +"%s"`
  # Run the command in a loop looking for output.
  until $(${cmd} | grep -q "${match}"); do 
    # Check the time so this does not loop forever.
    check_time ${start_time} ${MAXIMUM_WAIT_SECONDS}
    sleep ${sleep_seconds}
  done
}

# A platform neutral way to get the md5 hash sum of a file.
function md5sum_file() {
  if which md5sum > /dev/null 2>&1; then
    md5sum "$1" | awk '{ print $1 }'
  else
    md5 -q "$1"
  fi
}

# A platform neutral way to get the sha1 hash sum of a file.
function sha1sum_file() {
  if which sha1sum > /dev/null 2>&1; then
    sha1sum "$1" | awk '{ print $1 }'
  else
    shasum -a1 "$1" | awk '{ print $1 }'
  fi
}

# A platform neutral way to get the sha256 hash sum of a file.
function sha256sum_file() {
  if which sha256sum > /dev/null 2>&1; then
    sha256sum "$1" | awk '{ print $1 }'
  else
    shasum -a256 "$1" | awk '{ print $1 }'
  fi
}

# Create an archive and print the hash values for that file.
function create_archive() {
  local directory=$1
  shift
  local archive=$1
  shift
  # The rest of the arguments are for the tar command.
  local files="$@"
  # Change to the target directory.
  cd ${directory}
  tar -cvzf ${archive} ${files}
  echo "$(ls -hl ${archive} | cut -d ' ' -f 5) $(basename ${archive})"
  echo "$(md5sum_file ${archive}) $(basename ${archive})"
  echo "$(sha1sum_file ${archive}) $(basename ${archive})"
  echo "$(sha256sum_file ${archive}) $(basename ${archive})"
  cd -
}

# Return the operating system of the host system.
function get_os() {
  local os
  # Get the kernel name.
  case "$(uname -s)" in
    Darwin)
      os=darwin
      ;;
    Linux)
      os=linux
      ;;
    *)
      echo "Unsupported OS.  Must be Linux or Mac OS X." >&2
      exit 1
      ;;
  esac
  echo ${os}
}

# Return the architecture of the host system.
function get_arch() {
  local arch
  # Get the machine hardware name.
  case "$(uname -m)" in
    x86_64*)
      arch=amd64
      ;;
    i?86_64*)
      arch=amd64
      ;;
    amd64*)
      arch=amd64
      ;;
    aarch64*)
      arch=arm64
      ;;
    arm64*)
      arch=arm64
      ;;
    arm*)
      arch=arm
      ;;
    i?86*)
      arch=x86
      ;;
    s390x*)
      arch=s390x
      ;;
    ppc64le*)
      arch=ppc64le
      ;;
    *)
      echo "Unsupported arch. Must be x86_64, 386, arm, arm64, s390x or ppc64le." >&2
      exit 1
      ;;
  esac
  echo "${arch}"
}