I was using Blender, I was wondering how to set different commands to hot keys. Specifically the limit selection to visible command

Here’s how I set up my hotkey for limit selection to view:
With your default scene opened:
Go into User Preferences > Input > 3D View Mesh > Add New > click the small arrow to expand the new preference >
in the input field that says “none” type: wm.context_toggle > hit enter > a new input field appears:" Context Attributes" > type in that field: space_data.use_occlude_geometry
To the right of the filed you changed to wm.context_toggle is where you set the hotkey you will use. Click on the field that says “A” > it now says “Press a key” > press the key you wish to use > below that filed are boxes labeled “Shift” “Ctrl” “Alt” Cmd", check any of those if you want to use it. For example for setting up the hotkey alt + shift V: click on the “A” > press “V” > check the Shift and Alt boxes

Minimize all fields.
At the bottom of the User Preferences click “Save As Default”

I like to export my key config for back up, so you may want to do that also.