Mac – How to get Ctrl+return key binding for emacs in iTerm2 working

Changing preferences and running, defaults -currentHost read -g shows you what changes are being written. I was going to write up a short bash script to automate it, but it looks like I was beaten to the punch:

#!/bin/bash                                                                      

mappingplist=com.apple.keyboard.modifiermapping

if [ $1 == "emacs" ]; then
    echo "Switching to emacs modifiers"
    defaults -currentHost write -g $mappingplist '(                              
                {                                                                
            HIDKeyboardModifierMappingDst = 4;                                   
            HIDKeyboardModifierMappingSrc = 2; },                                
                {                                                                
            HIDKeyboardModifierMappingDst = 12;                                  
            HIDKeyboardModifierMappingSrc = 10;                                  
        },                                                                       
                {                                                                
            HIDKeyboardModifierMappingDst = 2;                                   
            HIDKeyboardModifierMappingSrc = 4;                                   
        },                                                                       
                {                                                                
            HIDKeyboardModifierMappingDst = 10;                                  
            HIDKeyboardModifierMappingSrc = 12;                                  
        })'


else
    echo "Switching to default modifiers"
    defaults -currentHost delete -g $mappingplist
fi

The script takes one argument, if the argument is emacs, then it swaps command and control, if the argument is anything else it restores the defaults.

http://forums.macrumors.com/showthread.php?t=949280

I've developed a terminal for iOS (it is not released, is intended as a base for other projects) and I have tried for hours to see any kind of event or modifier when meta keys are used on an external keyboard. The only way to get these events is to use private APIs and if you do that you can't get your app on the store. I have filed an issue (Apple rdar 10283552) and hopefully this will change in a future release.

So the problem is not your keyboard, it is iOS. I think you have found the best solution with key chords, unless you want to use one of the better apps like Prompt, which gives you "soft" meta keys on the screen - but the whole point is to keep your hands on the external keyboard, I know.

I don't know for sure if Prompt keeps those meta keys visible when a BT keyboard is connected - it can be done in code - if it did maybe soft metas would be better than nothing.