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
: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"
You can think the working as, for the range (default whole file), execute
the colon command(ex) "cmd" for the lines matching
. 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).
Display context (5 lines) for all occurences of a pattern
<< same as first, but with some beautification >>
Delete all lines matching a pattern
Delete all blank lines (just an example for above)
Double space the file
<< the above one also works >>
Copy all lines matching a pattern to end of file
Yank all lines matching a pattern to register 'a'
Increment the number items from current line to end-of-document by one
:.,$g/^\d/exe "normal! \
Comment (C) lines containing "DEBUG" statements
g/^\s*DEBUG/exe "norm! I/* \
A */\ "
A Reverse lookup for records
(eg: An address book, with Name on start-of-line and fields after a space)
?^\w?p "if only name is interested
/ka|?^\w?p|'ap "if name and the lookup-line is interested
/?^\w?|+,/^[^ ]/-1p "if entire record is interested
Reverse a file (just to show the power of 'g')
Foot note 1: use :v to negate the search pattern
Foot note 2: Some explanation of commonly used commands with :g
:2,8co15 => Copy lines 2 through 8 after line 15
:4,15t$ => 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
eg. :help :k