command line IntelliJ on Mac OS X

Question

I'm trying to launch IntelliJ on command line in Mac OS X to use it's diff tool. Theoretically idea.sh diff file1 file2 should work. In practice there are some issues with the file which I think I worked around (removing some arguments to readlink etc).
However when it does start, it wants me to enter license information (even though an instance of Intellij is already running and the license is there). Which leads me to believe that there is some sort of separation of command line world vs non-command line world on Mac OS X? IS that true?
Also when I select 30 days eval it proceeds to give me the following exception:

java.lang.IllegalArgumentException: Argument 0 for @NotNull parameter of com/intellij/openapi/fileEditor/impl/FileEditorProviderManagerImpl.getProviders must not be null     at com.intellij.openapi.fileEditor.impl.FileEditorProviderManagerImpl.getProviders(FileEditorProviderManagerImpl.java)     at com.intellij.openapi.diff.impl.highlighting.EditorPlaceHolder.setContent(EditorPlaceHolder.java:73)     at com.intellij.openapi.diff.impl.highlighting.DiffPanelState$1.run(DiffPanelState.java:38)     at com.intellij.openapi.application.impl.ApplicationImpl.runWriteAction(ApplicationImpl.java:864) ... 

Answer 1

IntelliJ can install a command line launcher for you, adding it to a PATH directory would make it as any other commands on the system. The command is "idea".