Re: how to create a diff in old file new file format (for code reviews)

[Michael J Gruber <git@drmicha.warpmail.net>]

aerosmith venit, vidit, dixit 14.12.2010 01:07:
> 
> Hi,
> 
> I am trying to create a diff such that the original file (entire file) is
> saved something like file1.h.old and the new modified file as file1.h.new. I
> have read the various options for git-diff* tools but could not find one
> such utility. All I get is the removals and additions as a diff. Does anyone
> know how to create one with the help the available git utils? The only
> method that I can think of is to do everything manually. Any help w.r.t.
> this is really appreciated. Thanks in advance.

You could script around this e.g. with an external diff-helper. The
easiest way is to reuse difftool. For example,

git difftool -y -x echo <revexpression>

will give you pairs of names of temporary files for old/new, where
<revexpression> is what you would give to "git diff" to specify what to
diff.

With the patch I'm sending in a minute, the helper you specify with "-x"
can also access the basename easily, so that you could use "-x oldnew"
with a script "oldnew" containing

#!/bin/sh
cp "$1" "$BASE".old
cp "$2" "$BASE".new

Even without the patch, you could use

git difftool -y -x 'cp "$LOCAL" "$BASE".old; cp "$REMOTE" "$BASE.new";
#' <revexpression>

(all on one line) directly. But this requires insider knowledge and may
break some day.

Cheers,
Michael