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util:vim

vim

vim is not an editor with killerfeatures included,
but a killerfeature with an included editor.

modelines

Using modelines, you can define per file settings inside the file itself.
Cause modelines are disabled per default, they have to be activated first:

set modeline

The variable modelines defines how many lines from top (or bottom, respectively) of the file are expected to contain a modeline:

set modelines=5

You can define modelines via two ways, although the old scool method is a little more compatible: 1. new school:

         [text]{white}{vi:|vim:|ex:}[white]{options}
 
 [text]          any text or empty
 {white}         at least one blank character (<Space> or <Tab>)
 {vi:|vim:|ex:}  the string "vi:", "vim:" or "ex:"
 [white]         optional white space
 {options}       a list of option settings, separated with white space or ':',
                 where each part between ':' is the argument for a ":set"
                 command
 
 Example: >
    vi:noai:sw=3 ts=6

2. old school:

         [text]{white}{vi:|vim:|ex:}[white]se[t] {options}:[text]
 
 [text]          any text or empty
 {white}         at least one blank character (<Space> or <Tab>)
 {vi:|vim:|ex:}  the string "vi:", "vim:" or "ex:"
 [white]         optional white space
 se[t]           the string "set " or "se " (note the space)
 {options}       a list of options, separated with white space, which is the
                 argument for a ":set" command
 :               a colon
 [text]          any text or empty
 
 Example: >
    /* vim: set ai tw=75: */

Helpful Settings

Variable Abbrev Type Meaning
filetype ft String defines the filetype, used for syntax highlighting
modeline ? Boolean activates the interpretation of modelines
modelines ? Integer holds the count of lines from top or bottom of the file to be searched for modelines
shiftwidth sw Integer number of columns for auto indenting
tabstop ts Integer number of columns for a tab ATTENTION: this should match shiftwidth
textwidth tw Integer specifies the maximum line length, longer lines will be broken after white space using <EOL>
linebreak lbr Boolean wrap long lines, for displaying only (no changes are done to the file itself)

Using this line in the .vimrc file, the cursor is placed at the last known position in the file when opening:

:au BufReadPost * if line("'\"") > 0 && line("'\"") <= line("$") | exe "normal g'\"" | endif

Commands To Know By Heart

Command Meaning
^g show file status information
ZZ like :wq, but vim-specific
yy copy actual line to clipboard
p paste clipboard after the cursor
P paste clipboard before the cursor
Changing Modes
I insert at beginning of line
A insert at end of line
^v visual block mode (selection of fields)
Movement Commands
:<num> goto line <num>
gg goto first line
G goto last line
z. scroll actual line to the middle of the screen
z- scroll actual line to the bottom of the screen
zRETURN scroll actual line to the top of the screen
f<char> place cursor to the next occurence of <char> in the line
F<char> place cursor to the last occurence of <char> in the line
{ place cursor to the beginning of the actual/last paragraph
} place cursor to the end of the actual/next paragraph
Searching
/<expr> search forward for <expr>
?<expr> search backward for <expr>
* search forward for the word under the cursor
# search backward for the word under the cursor
Windows
:sp [fname] horizontally split window, open <fname> or actually opened file
:vsp [fname] vertically split window, open <fname> or actually opened file
:to vsp [fname] vertically split window, but occupy the full height
^ww switch window focus
^w= equal sizes of all windows
^wr rotate windows
^wR rotate windows (other direction)
^w_ maximize focused window
Folding
zr increase foldlevel by one
zR set foldlevel to max (remove all foldings)
zm decrease foldlevel by one
zM set foldlevel to 0 (close all foldings)
zX update folds, apply foldlevel
zx update folds, apply foldlevel and do zv
zo open fold under Cursor
zO open all folds under Cursor recursively
zc close fold under Cursor
zC close all folds under Cursor recursively
zv unfold just enough to show line in which Cursor is located
Vim Help Context
:h <expr>^d show help topics matching <expr>
^5 follow hyperlink
^] follow hyperlink
^t</wowiki> | go back | | <nowiki>^o go back

Ranges

Example Meaning
. actual line
2,3 all from line 2 till inclusively line 3
,$ all from beginning of file till the end
+2,+3 all from two lines after cursor till three lines after cursor

Mappings

Mappings are a useful utility to define command aliases and little macros inside vim.

Mapping Commands

    commands:                                 modes: ~
                                          Normal     Visual  Operator-pending ~
:map   :noremap   :unmap   :mapclear        yes        yes        yes
:nmap  :nnoremap  :nunmap  :nmapclear       yes         -          -
:vmap  :vnoremap  :vunmap  :vmapclear        -         yes         -
:omap  :onoremap  :ounmap  :omapclear        -          -         yes

                                          Insert  Command-line  Lang-Arg ~
:map!  :noremap!  :unmap!  :mapclear!       yes        yes         -
:imap  :inoremap  :iunmap  :imapclear       yes         -          -
:cmap  :cnoremap  :cunmap  :cmapclear        -         yes         -
:lmap  :lnoremap  :lunmap  :lmapclear       yes*       yes*       yes*

Excerpt from vim help context *map-modes*

Mapping Keycodes

The vim help context contains a list of codes for special keys:

:help keycodes

Samples

Defining a mapping is as simple as:

:imap try try {<Enter>} catch(Exception e) {<Enter><Enter>}<Esc>3ko

The effect can be tested in insert mode, typing try.

Removal of the mapping defined above is done via:

:iunmap try

cTags

Especially when debugging code, cTags are a wonderful tool when it comes to manually tracing through the code flow. Creation of the tags-file is often as simply as issuing a

make tags

or

ctags -R .

after that, one can jump to the definition of a code element by hitting ^5 or ^[. When the destination is not the expected one, it's helpful to check alternative targets using :ts, then selecting an entry by entering the corresponding number. Jump back using ^t.

ctags.vim

The script ctags.vim helps combining the power of cTags and vim. After downloading it has to be placed inside one's plugin dir (e.g. ~/.vim/plugin).

For a quick start, the following two ex-commands have to be given to enable the script's functionality:

:let g:ctags_statusline=1
:CTAGS

when everything was done right, the name of the function the cursor is currently positioned at is printed in the status bar.

Seamless Integration in Vim

On my notebook, I've setup ctags.vim like so:

  • save the script as ~/.vim/plugin/ctags.vim
  • create or edit the file ~/.vim/ftplugin/c.vim:
let g:ctags_statusline=1
CTAGS

Now upon opening a file with suffix .c, the plugin is automatically being loaded and activated (leads to an error if no tags file was found, but nothing fatal or disturbing).

Displaying Non-Printable Chars

Especially tabs and spaces are characters that can't be distinguished without further help from vim. As this is often necessary (e.g. for a clean C Coding Style), help is near:

Insert the following into your .vimrc to make the set list command output more useful stuff:

" Show tabs, trailing spaces, long lines
"set list listchars=tab:>_,trail:_,extends:+ " ,eol:$
" disable it by default
set listchars=tab:>_,trail:_,extends:+ " ,eol:$

The code below adds some more invasive displaying. Not only because it's enabled by default, but also because of the nice red colour. :-)

" show trailing spaces and spaces before tabs (this is better)
hi link localWhitespaceError Error

" match trailing spaces (being displayed right from the start)
"au Syntax * syn match localWhitespaceError /\s\+$/ display
" match trailing spaces, but not as soon as they are being typed
" au Syntax * syn match localWhitespaceError /\(\zs\%#\|\s\)\+$/ display
" same as above, but allow highlighting inside other syntax groups (comments for instance)
au Syntax * syn match localWhitespaceError /\(\zs\%#\|\s\)\+$/ display containedin=ALL

" show space before tab
au Syntax * syn match localWhitespaceError / \+\ze\t/ display containedin=ALL

Skeletons

Having skeletons (templates) when creating certain types of files is quite easy thanks to vim's powerful scripting language:

au BufNewFile <pattern> 0r <path_to_skeleton>

For instance, having a skeleton for tex letters at ~/.vim/skel/letter.tex:

au BufNewFile *.letter.tex 0r ~/.vim/skel/letter.tex

will insert the skeleton's content into every new file with name matching “*.letter.tex”.

util/vim.txt · Last modified: 2015/11/11 17:41 by phil