Ubuntu – Fixing CTRL-* in vim under GNU screen

gnu-screenUbuntuvim

When running vim under GNU screen, I'm finding that combinations of CTRL with the arrow and Pg* keys don't work as expected.

I'm using the Ubuntu 10.10 vim-gnome package.

On a different machine, also running Ubuntu, this did work without problems; unfortunately I don't have that configuration available to me now.

There is a related question here: How to fix Ctrl + arrows in Vim?

However, the suggested solution there is to remap vim's keybindings to work with the terminal emulator, in that case PuTTY. I don't recall doing anything of the sort, and suspect that there is a screen configuration option which will resolve this issue.

There's also a thread on the gnu-screen mailing list which suggests that running vim via $ TERM=xterm vim is an appropriate fix or workaround. This does work, but I'm a bit concerned that there might be side effects. It also doesn't sound familiar enough to be the solution I set up on the other machine (if a solution was necessary).

Best Answer

As intuited stated in his update, adding term xterm to the ~/.screenrc file seems to fix this problem.

Related Solutions

Fix Ctrl + Arrows in Vim – How to Resolve Keyboard Issues in Vim

Figure out exactly what escape sequence your terminal sends for Ctrl+arrow by typing Ctrl+V, Ctrl+arrow in insert mode: this will insert the leading ESC character (shown as ^[ in vim) literally, followed by the rest of the escape sequence. Then tell vim about these escape sequences with something like

map <ESC>[5D <C-Left>
map <ESC>[5C <C-Right>
map! <ESC>[5D <C-Left>
map! <ESC>[5C <C-Right>

I seem to recall that Putty has a default setting for Application Cursor Keys mode that's inconvenient (I forget why), you might want to toggle this setting first.

Note that although escape sequences vary between terminals, conflicts (i.e. an escape sequence that corresponds to different keys in different terminals) are rare, so there's no particular need to try to apply the mappings only on a particular terminal type.

Why is Vim eating up Ctrl when used with Ctrl+v and how to fix it

This is actually your terminal doing something weird, not Vim. Terminals have two sets of control sequences associated with cursor keys, for historical reasons: one for full-screen applications, often called “application cursor keys mode”, and one for read-eval-print applications (e.g. shells).

In the old days, read-eval-print applications didn't have any line-editing features, and it was intended that the terminal, or the OS terminal driver, would eventually become more sophisticated. So the terminal sent control sequences intended for the terminal driver. Somehow the Unix terminal drivers never gained decent line-editing features; these were added to applications instead (e.g. through the readline library).

Your terminal is sending ␛OD for Ctrl+Left in line edition cursor keys mode, and ␛[D in application cursor keys mode. You have two options:

Configure your terminal not to make a difference between the two modes. How to do this is entirely dependent on your terminal emulator.
Live with it. Since any given application always sets the terminal in the same mode, just configure its key bindings according to the mode it uses.

Best Answer

Related Solutions

Fix Ctrl + Arrows in Vim – How to Resolve Keyboard Issues in Vim

Why is Vim eating up Ctrl when used with Ctrl+v and how to fix it

Related Question