in vim, enter is being mapped to a ctrl key custom key map
mapping, vim
Solution
You have to use a different control combination for your mapping, e.g. `<C-g>`.
Due to the way that the keyboard input is handled internally, this unfortunately isn't generally possible today without these side effects, even in GVIM. Some key combinations, like Ctrl + non-alphabetic cannot be mapped, and Ctrl + letter vs. Ctrl + Shift + letter cannot be distinguished. (Unless your terminal sends a distinct termcap code for it, which most don't.) This also applies to `<Tab>` / `<C-I>`, `<CR>` / `<C-M>` / `<Esc>` / `<C-[>` etc. (Only exception is `<BS>` / `<C-H>`.) This is a known pain point, and the subject of various discussions on vim_dev and the #vim IRC channel.
Some people (foremost Paul LeoNerd Evans) want to fix that (even for console Vim in terminals that support this), and have floated various proposals, cp. http://groups.google.com/group/vim_dev/browse_thread/thread/626e83fa4588b32a/bfbcb22f37a8a1f8
But as of today, no patches or volunteers have yet come forward, though many have expressed a desire to have this in a future Vim 8 major release.
Problem
I am encountering some strange behavior with a keymap in vim that uses the ctrl key. I would guess that this has a simple cause and solution, but I just can't see it. During the editing of restructuredtext, I find myself typing things like ``` :math:`x` ``` often (this :math: role will cause whatever is inside the ticks to be typeset as math in e.g. the latex output). I want to map a key like m to enter :math:`` into the text and position the cursor inside the ticks. I have done this ``` map m i:math:``ha ``` and that seems to work fine. However, I would like to be able to use this map in insert mode. For that, I thought that using ctrl+m would be best. I've done ``` imap <c-m> :math:``ha ``` Although that correctly inputs :math:`` and positions the cursor inside the ticks when I do ctrl+m, the trouble is that after this point, every time I press enter in insert mode, it runs the same command as if I typed ctrl+m. In other words, enter in insert mode now seems to be mapped to ``` :math:``ha ``` as well. It seems like it is definitely something to do with using the ctrl key. If I bind e.g. the F5 key as follows ``` imap <F5> :math:``ha ``` everything is fine. I can use the e.g. F5 key and save myself any further bother, but I would like to know what is going on for future reference. Is there something basic about the use of the ctrl key in a key map that I am missing? thank you,