t+1: Matt Wilson’s blog

The Ohio Technology Investment Tax Credit is a fantastic boon to starting businesses. But applying for it is really boring.

Anyway, when I opened up vim to work on my application, I found a really good tip of the day, copied below:

VimTip 295: Line/word/file/whatever completion

In addition to vimtip #291 you can use whole completion mode. It can complete whole lines (<C-x>l, then <C-p>, <C-n>), filenames (<C-f>), keywords, words from custom dictionary and many, many others. During coding it usually saves a LOT of key strokes This mode has many other powerful features, for example when completing word (by &;tlC-x><C-p> or just by <C-p>) you can continue completion with another <C-x<>-p>. For example, after writing such text:

this is first line
second line is here

Placing cursor at third line and pressing <C-x>l will double last line - <C-n>, <C-p> in this moment can be used to manipulate completed line. Or, instead of completing whole line you can press ‘f’ and then complete by <C-p> which will result in ‘first’ word. After that you can <C-x><C-p> to get ‘line’ word (since this is next word after ‘first’). Try yourself for other powerful combinations.

Now I just need a completion mode that will calculate intelligent sales forecasts, and this application would be done.

This vim tip of the day is really good. I use the :g/pattern/d command occasionally, but there is a lot more possible. Here’s the tip:


VimTip 227: Power of :g
http://vim.sourceforge.net/tip_view.php?tip_id=
 
:g is something very old and which is very powerful. I just wanted to illustrate the use of it
with some examples. Hope, it will be useful for someone.
 
Brief explanation for ":g"
-------------------------
Syntax is:
    :[range]:g/<pattern>/[cmd]
You can think the working as, for the range (default whole file), execute
the colon command(ex) "cmd" for the lines matching <pattern>. Also, for all
lines that matched the pattern, "." is set to that particular line (for
certain commands if line is not specified "." (current line) is assumed).
 
Some examples
-------------
Display context (5 lines) for all occurences of a pattern
    :g/<pattern>/z#.5
    :g/<pattern>/z#.5|echo "=========="
    << same as first, but with some beautification >>
Delete all lines matching a pattern
    :g/<pattern>/d
Delete all blank lines (just an example for above)
    :g/^\s*$/d
Double space the file
    :g/^/pu =\"\n\"
    :g/^/pu _
    << the above one also works >>
Copy all lines matching a pattern to end of file
    :g/<pattern>/t$
Yank all lines matching a pattern to register 'a'
    0"ay0:g/<pattern>/y A
Increment the number items from current line to end-of-document by one
    :.,$g/^\d/exe "normal! \<c-a>"
Comment (C) lines containing "DEBUG" statements
    g/^\s*DEBUG/exe "norm! I/* \<Esc>A */\<Esc>"
A Reverse lookup for records
(eg: An address book, with Name on start-of-line and fields after a space)
    :g/<patern>?^\w?p               "if only name is interested
    :g/<patern>/ka|?^\w?p|'ap       "if name and the lookup-line is interested
    :g/<patern>/?^\w?|+,/^[^ ]/-1p  "if entire record is interested
Reverse a file (just to show the power of 'g')
    :g/^/m0
 
Foot note 1: use :v to negate the search pattern
Foot note 2: Some explanation of commonly used commands with :g
:2,8co15 => Copy lines 2 through 8 after line 15
:4,15t$  => Copy linesa 4 through 15 towards end of document (t == co)
    :-t$  => Copy previous line to end of document
     :m0  => Move current line to the top of the document
:.,+3m$-1 => Move current line through cur-line+3 to the last but one line
             of the document
Foot note 3: Commands used with :g are ex commands, so a help search should
             be,
                :help :<help-topic>
                eg. :help :k


vimdiff is fantastic. Follow these instructions to make subversion use vimdiff when you run svn diff.

Get this diffwrap.sh script and save it anywhere. I saved mine in my $HOME/bin directory. Make sure to make it executable! I’m showing it below:

#!/bin/sh
 
# Configure your favorite diff program here.
DIFF="/usr/bin/vimdiff"
 
# Subversion provides the paths we need as the sixth and seventh
# parameters.
LEFT=${6}
RIGHT=${7}
 
# Call the diff command (change the following line to make sense for
# your merge program).
$DIFF $LEFT $RIGHT
 
# Return an errorcode of 0 if no differences were detected, 1 if some were.
# Any other errorcode will be treated as fatal.


Then change your $HOME/.subversion/config file to point at that script:

[helpers]
diff-cmd = /home/matt/bin/diffwrap.sh


Then go diff a file!

See this section of the svn book for all the details.