shell script to download [kxl]ubuntu release iso ... just rename the script to requested edition-release-type-platform

ubuntu-14.04-desktop-amd64.sh

#!/bin/sh

name="${0##*/}"
name="${name%.sh}"
edition="${name%%-*}"
version="${name#*-}"
version="${version%%-*}"

# use main ubuntu cdimage server
if [ "$edition" = 'ubuntu' ]; then

  # use the main ubuntu releases server
  root="http://releases.ubuntu.com/$version"

  # or use an ubuntu releases mirror
  root="http://www.mirrorservice.org/sites/releases.ubuntu.com/$version"

  # or use a local ubuntu releases mirror
  root="http://releases.ubuntu.cz/$version"

else

  # use the main ubuntu cdimage server
  root="http://cdimage.ubuntu.com/$edition/releases/$version/release"

  # or use an ubuntu cdimage mirror
  root="http://www.mirrorservice.org/sites/cdimage.ubuntu.com/cdimage/$edition/releases/$version/release"

  fi

echo "get $edition $version from $root" >&2

[ -f "$name.md5" ] || wget "$root/MD5SUMS" -O - | grep "$name.iso" > "$name.md5" || { rm "$name.md5"; exit 1; }
wget -c "$root/$name.iso" || exit $?

md5sum -c "$name.md5"