The trick is that when you untar the processing package, nothing that comes out of the archive is executable. It's a sensible default, but means you gotta specifically make things executable. If you know how linux works, just chmod the "processing" script 755, chmod everything in the included java/bin/ as 755 and run ./processing from its directory.
For the rest of you, here's how I did it, in extra-verbose detail, step-by-step:
- Download Processing 1.2.1 for Linux.
- Reveal the downloaded file in a directory window.
- (In Chrome: click "Show all downloads," find processing, click "Show in Folder")
- (in Firefox: the download manager lists your files, right click processing and click "Open Containing Folder")
- Drag the processing tgz file onto your desktop. (For this example, at least...)
- Right-click the tgz file on the desktop and select "Extract Here"
- Open a new Terminal window.
- (it's in the main menu: Applications -> Accessories -> Terminal)
- In the Terminal, change directory into Desktop, and into the extracted processing dir.
- (in this example: type "cd Desktop/processing-1.2.1" in the terminal, but your version number might differ.)
- Make the processing script executable by all users.
- (for this example: type "chmod a+x processing" in the terminal)
- The package includes a compatible version of java, which also needs to be made executable.
- (for this example: type "chmod a+x java/bin/*" in the terminal)
- And now you can get processing to open by running it from a Terminal.
- (in this example: type "~/Desktop/processing-1.2.1/processing &" in a terminal
- And that's it! In the future, I just open a Terminal and type "~/Desktop/processing-1.2.1/processing &" again.