Tips from Bram, be sure to read them.

Interaction with X

Vim works wonderful together with X. Besides the graphical version (gvim), it's also possible to start vim in a terminal like xterm, konsole, gnome-terminal or Terminal.app on Mac OS X. With the right options, it's still aware of the X clipboard, the mouse, et cetera.

First turn on the mouse with:

  :set mouse=a

vim has one default clipboard, but has an extra one under any a-z character. The two X clipboards are available too, but under a special character. To paste the X clipboards, paste either the + or * clipboard:

The star buffer contains the so-called X 'primary' for which you just select something with the mouse:

  <esc>"*p

The plus buffer contains the so-called X 'clipboard' for which you selected with the mouse, then right-clicked and selected 'copy', or pressed a shortcut like CTRL-C or similar:

  <esc>"+p

If this doesn't work, check the following things:

• You're running vim as a different user, which happens when you start vim with for instance 'sudo'. Solution: don't do that -or- make the other user have access to the magic cookies in your ~/.Xauthority file.
• Vim is started in compatibility mode. Solution: don't use 'vi' to start, use 'vim'. On RedHat and CentOS, it's not enough to start 'vim', use 'vimx'. If this program is not present, be sure to install the package 'vim-X11'.
• Vim is not compiled with the right options. To check: 'vim --version | grep xterm', and the output must show '+xterm_clipboard'. Get the latest source, then compile with: ./configure --with-x --with-features=normal --enable-gui && make. On Debian and derivatives, you'll need the xorg-dev package, on RedHat and derivatives, the xorg-x11-devel package.
• The mouse is turned off. Type ":set mouse" to check the setting. Type ":set mouse=a" to turn it on.
• You used SSH to log into a remote machine and X11 is not forwarded. To check: start a simple X program like 'xclock'; if it answers "Error: can't open display:" then X is not forwarded. Solution: start ssh with option '-X'.
• You used SSH with -X and X11 is still not forwarded (i.e. xclock doesn't work). To check whether the system administrator has configured the SSH daemon to deny X11 forwarding, add the -v option, and check whether the following line shows up and the request is not denied. If this is the problem, ask your sysadmin to add the line 'X11Forwarding true' to /etc/ssh/sshd_config.

  $ ssh -v -X remotemachine
  ...
  debug1: Requesting X11 forwarding with authentication spoofing.
  ...

• You used SSH with -X and X11 is still not forwarded. Use the -v option as above, and check for the following line. If it appears, ask your sysadmin to install the xauth program.

  debug1: Remote: No xauth program; cannot forward with spoofing.

If you are using Apple Mac OS X:

• You might not have an X server installed. From version 10.8 (Mountain Lion), OS X no longer includes an X server. Download XQuartz.
• You are working in Terminal. The included vim version does not have the xterm_clipboard option compiled in. There's MacVim for a graphical version, or else edit the options of the Macports version (see below).
• You are working on a remote server through Terminal. All the above checks out fine, and in the dock, the X11.app is active. The trick here is that the remote vim instance will put your content in the clipboard (of the locally running X11.app) when you're using "+y, but you additionally need to press Cmd-C to copy the X11 buffer to your OS X clipboard. Alternatively, you can activate X11.app, go to preferences and on the third tab (Pasteboard), be sure that all options are activated. (On Snow Leopard, the last option by default is off.)
• It worked, but now no longer does so. Close and quit terminals and X11.app, then start terminal again and log in to the remote machine. Start xclock, then quit it. Start vim and try yanking a line into the "+ buffer. Paste in OS X; it should work again. I'm not sure what the reason is for this strange behaviour, perhaps it's due to changing IP addresses. I've seen it multiple times.

Vim on OS X

If you're running Mountain Lion (i.e. OS X 10.8), first install an X server: XQuartz

To get support for the X11 clipboard, install the MacPorts or the Homebrew version. If you don't have any of those installed yet (WHAT?!), follow the instructions on their website. When that's done:

Vim via MacPorts

Install vim:

 $ sudo port install vim

Then edit the file /opt/local/var/macports/sources/rsync.macports.org/release/ports/editors/vim/Portfile and search for the line --without-x, and make sure it reads --with-x. Recompile with the following command:

 $ sudo port upgrade -n --force vim

Make sure to put /opt/local/bin in your path before anything else. Check the results by typing vim --version, which should say +xterm_clipboard somewhere below.

Vim via Homebrew

TODO

Macros

Put this in your .vimrc to run editor contents through an external program:

  map   <f9>   :w<CR>:!perl -c %<CR> 

Substituting line feeds

To replace line feeds (UNIX line feeds) in a file, use \n. To remove double empty lines in a file, do something like this:

  :%s/\n\n/\n/

Tags

Tags make it possible for vim to jump to function definitions under your cursor. First, you need to have exuberant ctags installed. It comes with most Linux distributions. For debian, install as follows:

  $ apt-get install exuberant-ctags

You have to create a tags file in your project its root directory:

  $ ctags -R

Then, add the following line to your .vimrc:

  set tags=tags;/

To jump to a function definition, put the cursor on the function call and press CTRL-]. To go back, press CTRL-t.

See also Tip 94 - Questions & Answers about using tags with Vim.

For code completion, type a few characters and press CTRL-n. See this blog entry: vim word and code completion.

Some keystrokes

Some commands

Compiling vim

If you want it done right, compile it yourself. The broken versions so casually strewn around your favorite Linux system are not to be taken seriously. Serious hackers compile their own editors. That said, here is my favorite stanza to compile vim on Debian Linux (Squeeze):

 $ ./configure --prefix=$HOME/opt/vim73 --with-x \
    --with-features=normal --enable-pythoninterp \
    --with-python-config-dir=/usr/lib/python2.6/config \
    --enable-gui && make

Cooperation with Python

You definitely want code completion in Python. To enable this, first make sure vim is compiled with Python support (type vim --version and check to see if there's a plus in front of the python option). Then add the following line to your .vimrc:

 autocmd FileType python set omnifunc=pythoncomplete#Complete

Auto-completion works via the CTRL-X CTRL-O command, but it's much easier to use tab for completion. Add the following lines to your .vimrc:

 function! SuperCleverTab()
     if strpart(getline('.'), 0, col('.') - 1) =~ '^\s*$'
         return "\<Tab>"
     else
         if &omnifunc != ''
             return "\<C-X>\<C-O>"
         elseif &dictionary != ''
             return "\<C-K>"
         else
             return "\<C-N>"
         endif
     endif
 endfunction

 inoremap <Tab> <C-R>=SuperCleverTab()<cr>

(From: Hacking Vim by Kim Shulz)

You'll also need exhuberant ctags installed; if you're running Debian, type:

 $ sudo apt-get install exuberant-ctags

Then go to your Python source code directory and type:

 $ ctags -R

To maintain the tags file, you could of course run it manually, but there's a vim plugin for that: [AutoTag http://www.vim.org/scripts/script.php?script_id=1343]. Download the .vim file and place it in your $HOME/.vim/plugin directory. Anytime you save a file, it'll re-run the ctags command.