vim you should know

If you use vim you should try these:

Use the file browser for local file management.

:browse e .

Equivalent to command line:

vim .

Use the file browser for remote file management.

:browse e scp://hostname/

Equivalent to command line:

vim scp://hostname/

Pipe to 'view -' instead of 'less' when you want syntax highlighting.

Side by side diff with editing

:e file_v1

:vert diffsplit file_v2

Equivalent to command line:

vimdiff -v file_v1 file_v2

Python File Type Plugin for Vim - Part 1

* Made a correction below. Using the ~/.vim/ftplugin directory for a file type plugin causes the plugin to be reloaded repeatedly causing any autocommands to be appended for BufWrite actions. This causes multiple executions of every autocommand every time you save the file. A better location is the ~/.vim/plugin directory. Where the plugin is loaded once at startup. I have changed the location below. *

I wanted to add some IDE style conveniences to my preferred editor, console Vim. Rather than reinventing the wheel I decided to search the Internet and start with what was already out there. I found a bunch of very useful scripts and snippets. In part 1 I am documenting some of what I found here by publishing a snippet that I have only made minor changes to to make it useful for my needs.

This script needs to be put in a file named python.vim and saved in ~/.vim/plugin. If the directory does not exist it needs to be created. The scripts create the pyflakes, pylinks, and pychecker commands that can be used at the vim command prompt, ':'. The pylint, pyflakes, pychecker packages will have to be installed as prerequisites for using these commands.

All three commands act on the current buffer's file name. Running one of the commands at the vim command prompt will open a Vim quickfix window which will seem familiar to anyone who has used a graphical IDE for development.

You can press c to close the quickfix window when it has the focus. You can double click with a mouse under X or press enter to go to the error or warning associated with the current quickfix line. This will take you to the line referred to by that message. You will have to restart vim if you have already loaded a python file during the currently loaded Vim session.

Here is the code:

function! PythonGrep(tool)
  set lazyredraw
  " Close any existing cwindows.
  cclose
  let l:grepformat_save = &grepformat
  let l:grepprogram_save = &grepprg
  set grepformat&vim
  set grepformat&vim
  let &grepformat = '%f:%l:%m'
  if a:tool == "pylint"
    let &grepprg = 'pylint --output-format=parseable --reports=n --indent-string="        "'
  elseif a:tool == "pychecker"

    let &grepprg = 'pychecker --quiet -q'

  elseif a:tool == "pyflakes"

     let &grepprg = 'pyflakes'

  else

    echohl WarningMsg

    echo "PythonGrep Error: Unknown Tool"

    echohl none

  endif

  if &readonly == 0 | update | endif

  silent! grep! %

  let &grepformat = l:grepformat_save

  let &grepprg = l:grepprogram_save

  let l:mod_total = 0

  let l:win_count = 1

  " Determine correct window height

  windo let l:win_count = l:win_count + 1

  if l:win_count <= 2 | let l:win_count = 4 | endif

  windo let l:mod_total = l:mod_total + winheight(0)/l:win_count |

  \ execute 'resize +'.l:mod_total

  " Open cwindow

  execute 'belowright cw '.l:mod_total

  nnoremap   c :cclose

  set nolazyredraw

  redraw!
endfunction

command! Pyflakes call PythonGrep('pyflakes')
command! PyFlakes call PythonGrep('pyflakes')
command! Pychecker call PythonGrep('pychecker')
command! PyChecker call PythonGrep('pychecker')
command! Pylint call PythonGrep('pylint')
command! PyLint call PythonGrep('pylint')

" These three are successively more informative and aggressive in their
" warnings with pyflakes as the least noisy. Only uncomment one.
"autocmd BufWrite *.{py} :Pyflakes
autocmd BufWrite *.{py} :Pychecker
"autocmd BufWrite *.{py} :Pylint

In Vim a single double quote, ", is considered the beginning of a comment for the rest of the line.

The benefit of having the autocmd run one of the Python lint programs every time you save the file is that you can never get too far from sane working code as any errors and warnings pop up. This, in your face, style of development can keep you from pulling your hair out over something as simple as a semicolon or comma typo and can also warn you about more complex problems and proper coding style.

More to follow. I will try to combine the output of the three commands as their output doesn't seem to overlap for the most part. And the noisier programs (pychecker and pylint) don't appear to give the same advice when it comes to warnings. pylinker is by far the noisiest of them all but all it's warnings are configurable.

Warning: If you are using tabs for indenting you will have to modify the pylint parameter '--indent-string='. Set it to the empty string for tabs, or the actual number of spaces used for indenting. In my code above I have it set for 8 spaces which is project specific.

Vim auto completion

I responded to a comment on the Daily Vim about auto completion. I decided to post it here as well as the comment ended up being kind of long. The comment by Casey asks if there is a way to turn off omni auto completion for perl as it goes through the entire POD collection evey time. I provide several solutions. Read the original article for a quicj intro to auto completion in insert mode in Vim.

The original article points out that there is built in auto completion in Vim. All you have to do is use it is type Ctrl-x Ctrl-o in insert mode and vim will try to complete what you have started typing or pop up a list of all completions if the cursor is not immediately preceded by anything.

Original comment follows:

Try this command to change the auto completion to the simpler syntax highlighting hints as the auto completer.

:setlocal omnifunc=syntaxcomplete#Complete

If that is what you always want for Perl add this to your .vimrc after all your other auto commands.

autocmd Filetype perl setlocal omnifunc=syntaxcomplete#Complete

If you want syntax completion rather than omni completion for all file types use * for the file type. If you want to fail over to syntax completion for file types that don't have omni completion put this in your .vimrc after your other auto commands.

if has("autocmd") && exists("+omnifunc")
autocmd Filetype *
\ if &omnifunc == "" |
\ setlocal omnifunc=syntaxcomplete#Complete |
\ endif
endif

You can also do something a little more complex which just disable the perlPOD part of the perl filetype omni complete.

Try this command:

let g:omni_syntax_group_exclude_perl = 'perlPOD'

generically it's:

let g:omni_syntax_group_exclude_{filetype} = 'comma,separated,list'

And you can get the complete list of syntax groups while in a file with the filetype in question with this command:

:syntax list

Then just add that command to your .vimrc to make it permanent.

Check out this help topic for more info:

:h ft-syntax-omni

*Updated

And for the complete low down on the idiosyncrasies of each filetype check out:

:h compl-omni-filetypes

And here's another tip I picked up Ctrl-o : in insert mode will allow you to run a command and then return to insert mode. Neatly avoiding the Esc : ... i or a syndrome.

*Updated again

FYI Pressing Ctrl-o in insert mode puts you in normal mode for one command. You are not limited to using : to get to the ex command line. You can use p to put or y to yank etc.

*Further updates

For those times when you just want to save keystrokes or avoid typos:

Ctrl-P completes from previous words in document
Ctrl-N completes from following words in document
Ctrl-X Ctrl-F completes file names
0 Ctrl-D removes all indent for the current line