(bash) Compare Version in `Major.Minor.Patch`

version_compare.sh

# Compare two versions, in version format Major.Minor.Patch
# It doesn't validate version format, only compare values.
#
# Usage :
#   version_compare <compared> <required>
#
# Example:
#   version_compare 0.13.1 0.11.0
#
# returns
# -1 if compared version below (older) then version required
#  0 if compared version same as required
#  1 if compared version above (newer) then version required
version_compare () {
  ver_cmp=$1  # version compared
  ver_req=$2  # version required

  EXAMPLE="version_compare <compared> <required>"

  if [[ -z $ver_cmp ]]; then
    >&2 printf "Error:\n\tCompared version not found\n"
    >&2 printf "Usage:\n\t${EXAMPLE}\n"
    exit 1;
  fi

  if [[ -z $ver_req ]]; then
    >&2 printf "Error:\n\tRequired version not found\n"
    >&2 printf "Usage:\n\t${EXAMPLE}\n"
    exit 2;
  fi

  recent=$(echo -e "$ver_cmp\n$ver_req" | sort -nr | head -1)

  if [[ $recent == $ver_req ]] && [[ $recent != $ver_cmp ]]; then
    # case 1 - compared version is old one.
    echo -1
    exit 0
  elif [[ $recent == $ver_cmp ]] && [[ $recent != $ver_req ]]; then
     # case 2 - compared version is a newer.
    echo 1
    exit 0
  elif [[ $recent == $ver_cmp ]] && [[ $recent == $ver_req ]]; then
    # case 3 - versions are same.
    echo 0
    exit 0
  else
    exit 3
  fi
}