If you've ever used Inkscape, GIMP, or any other X11/XQuartz program on a Mac, you've
probably noticed that the Command keys don't function in the same manner as they do for native Mac applications — that is, they cannot be used for keyboard shortcuts, as XQuartz will treat them as if they were the Option/Alt keys by default. Instead, we Mac users must hold down the Control key for shortcuts, which can be a bit awkward. Luckily, there's an easy way to tweak this behavior, and I'll show you just how to do it.
The process, step-by-step
1. First, open TextEdit and create a new document.
2. Convert the document to plain text via Format > Make Plain Text (⇧⌘T).
3. Enter the following text exactly as it appears:
keycode 63 = Control_L
keycode 67 = Control_L
keycode 71 = Control_R
add control = Control_L Control_R
4. Save the document with the filename set as ".Xmodmap" to your home folder. (Be sure that you've included the period at the beginning, and that the X
is capitalized.) The Plain Text Encoding must be set to "Unicode (UTF-8)"; the checkbox next to "If no extension is provided, use '.txt'." must not
If you've followed all of the steps above correctly, the following message will be displayed:
Names that begin with a dot "." are reserved for the system.
If you decide to go ahead and use a name which begins with a dot the file will be hidden.
5. Select "Use '.'".
Congratulations — you're done!
To verify everything's working properly, open an X11/XQuartz application. Both Command keys, as well as the Control key, should now function as you'd expect when using shortcuts.