What do you need to install Flex on Ubuntu?

1. The Flex SDK
2. Sun Java (needed for compiling the SWF binaries)

Set up and install Flex

Step 1. If you haven’t already, install Java. (If you aren’t sure, go ahead and try this step anyway.) First open up a terminal (Accessories menu > Terminal) and type the following:

[text]sudo apt-get install java-package sun-java6-jdk[/text]

This will take several minutes while the packages download and install. You’ll also need to agree to Sun’s license.

Step 2. Download the Flex SDK. The rest of this guide will assume you saved the SDK to your desktop: ~/Desktop.

Step 3. We need to create a directory for the Flex SDK. In a terminal window, enter the following:

[text]sudo mkdir /opt/flex[/text]

The “opt” directory is generally where optional application software packages live. (More info on the linux file system.) All we did here is make a new “flex” directory inside “opt”.

Step 4. Now we need to unzip the Flex SDK. Type the following in a terminal window:

[text]
cd ~/Desktop
unzip flex_sdk_4.zip -d tempflex
[/text]

What this does is unzip the contents of your download into a new and temporary directory on your Desktop called “tempflex”.

Step 5. After that’s complete, we need to move these files to “opt/flex” which we’ve already prepared for the SDK. Type the following in a terminal window:

[text]sudo mv tempflex/* /opt/flex/[/text]

This will move the contents of “tempflex” into “opt/flex”. If you want to make sure you moved everything, you can type the following into a terminal window:

[text]
cd /opt/flex
ls
[/text]

You should see a list of all the files in the directory.

Step 6. Last step. All we need to do now is let Ubuntu know where the new Flex compiler lives. Type the following in a terminal window to open up “~/.bashrc” in a text editor:

[text]gedit ~/.bashrc[/text]

The text editor will open your ~/.bashrc profile and we only need to add one line (I added it at the bottom of the file, but I’m not sure it matters).

[text]export PATH=/opt/flex/bin:$PATH[/text]

Save the file and close the text editor. Then exit all open terminal windows before opening a new one. This should ensure that your terminal loads the path that we just added.

You should now be able to compile your Flex projects with the “mxmlc” compiler command. To make sure, type the following in a terminal window to bring up the “help”:

[text]mxmlc –help[/text]

Looks good? Great. You’re all set. Happy Flex-developing.