vi editing of bash command line: Avoid execution upon exit?

How to do it

Bash doesn't seem to provide builtin support for this in form of a readline function like it does for editing and executing. However, there is bind -x command to invoke arbitrary shell function and $READLINE_* variables which can be combined to perform command-line editing, one just needs to call Vim to do the job:

function _editcommandline() { local tmp_file="$(mktemp "/tmp/bash-editinplace.XXXXXX")" echo "$READLINE_LINE" >| "$tmp_file" vim +"call cursor(1, $READLINE_POINT + 1)" "$tmp_file" READLINE_LINE="$(< "$tmp_file")" READLINE_POINT="${#READLINE_LINE}" rm -f "$tmp_file" } # bind to Ctrl-X+e combination bind -x '"\C-Xe": _editcommandline' 

How it works

Here we define function _editcommandline() and use bind to tell bash to invoke it when C-Xe combination is pressed.

Inside the function:

1. Temporary file is created.
2. The file is filled with current input line.
3. Vim is called to edit the line, positioning the cursor appropriately.
4. Current line is replaced with contents of the temporary file, which is later removed.
5. Cursor is positioned at the end of input line.

Limitation

The limitation of this approach is that you can edit only current input line, not whole command-line, but this is important only for multi-line commands.

Possible improvements

The function was written for demonstration purposes and can be further improved by:

1. Correctly positioning cursor in bash instead of moving it to the end.
2. Checking exit code of Vim to be able to discard saved changes with :cquit.

I have the following command in my .bashrc to do a similar thing:

set -o vi