While following How to install Android Studio on Ubuntu? and Complete Installation Guide for Android SDK / ADT Bundle on Ubuntu to install Android-studio as a solution for Android emulator independent of Virtual Box/VM-ware capability there is a proble that the file we download from Developer.Android.com as sdk-tools-linux-3859397.zip does not contain the add-ons and platforms and I can find just the tools folder .
Below image is from Complete Installation Guide for Android SDK / ADT Bundle on Ubuntu that shows the files used to be in downloading folder.
So when I try to run Android studio I get this message that No Android SDK is found.
In next step installing/updating components, it says that Android SDK is installed.
Next step says that Android SDK is up to date but SDK tools directory is missing.
And nothing works properly. ! Please specify a Android SDK Location.
Trying SDK location for android studio on ubuntu 14.10's solution, I couldn't find any "SDK Readme.txt"
The current direct link for SDK Tools package is (2018-12-31): https://dl.google.com/android/repository/sdk-tools-linux-4333796.zip. But, as others have already said in other responses to similar questions on SO, the best way is to let Android Studio handle the installation, because it will install other useful apps, too (emulator, platform tools, etc). In my case, I wasn't connected to the internet when I first started Android Studio, so I got stuck at the same error. After removing the ~/.AndroidStudio3.2 folder and a ./studio.sh restart, it asked me to download all the necessary apps (note: the dowload has ~1GB!) and then Android Studio started flawlessly!
If you are behind a proxy, do NOT configure the Automatic proxy configuration URL (URL to .pac file), because this didn't worked for me.
Configure the proxy manually, this fixed it for me.