Subversion: colordiff fo html files

(Mostly a reminder:)

Say you have some software project, hosted on some Subversion repository. You happily edit your files, and before committing you want to have a quick look at the edits you have done.

No problem, as simple as:
> svn diff 

But this outputs lots of text, not easily readable. Ok, lets' go with colordiff:
> svn diff | colordiff

And then you get drowned under floods of nice and flashy colors, and you have to painfully scroll your terminal. Well, what else ? A simple redirecting in a file won't keep the colors.

This is where another magic tool shows up: aha. Yeah, that's his name. It's a "ANSI to HTML" converter. Install it with sudo apt-get install aha, and then, go:
svn diff | colordiff | aha >mydiff.html

For conveniency, you can now add a new target to you makefile:

diff:
     svn diff | colordiff | aha >mydiff.html
     xdg-open mydiff.html

Thus, entering make diff at the shell will show you the current edits you have done up to now.
xdg-open is just the Gnome app that opens the default application associated with a file type. On Windows, just use the file name alone, as this OS has some mechanism to open the file with the default application when given a file name.

Edit 20141224: a small improvement: in order to keep track of all these generated diff files, you can append date/time to the filename so that each new one doesn't erase the previous one. This can be done easily with bash (not that hard for Windows either, but no time at present to figure that out):

ifndef COMPSPEC
NOW=$(shell date +%Y%m%d_%H%M)
BROWSER=xdg-open
endif

diff:
     svn diff | colordiff | aha >mydiff_$(NOW).html
     $(BROWSER) mydiff_$(NOW).html

Notice the conditional, so that this makefile should also work out-of-the-box under Windows (except for the time/date, but if you send it to me, I'll publish it ;-) )