UPDATE: This is easier now! See my new post, “Side-by-side diffs for Mercurial (hg) & icdiff revisited”.
Ever wish for
hg diff in side-by-side view? I find it much easier to scan, assuming you have the horizontal real-estate in your terminal. Here is a simple guide to setting up side-by-side diffs in Mercurial on Linux/OSX:
1. Install icdiff
The grunt of this work will be done by icdiff, an excellent tool by Jeff Kaufman. Download and install icdiff, making sure
/usr/local/bin is in your
2. Adapter scripts
Since icdiff only operates on individual files, we need to provide an adapter for it to work with directories. We’ll use a modified version of Bryan O’Sullivan’s hg-interdiff script. Drop this into
~/scripts/hg-icdiff, and then run
chmod +x ~/scripts/hg-icdiff to make it executable:
#!/usr/bin/env python # # Adapter for using interdiff with mercurial's extdiff extension. # # Copyright 2006 Bryan O'Sullivan <firstname.lastname@example.org> # # This software may be used and distributed according to the terms of # the GNU General Public License, incorporated herein by reference. import os, sys def walk(base): # yield all non-directories below the base path. for root, dirs, files in os.walk(base): for f in files: path = os.path.join(root, f) yield path[len(base)+1:], path else: if os.path.isfile(base): yield '', base # create list of unique file names under both directories. files = dict(walk(sys.argv)) files.update(walk(sys.argv)) files = files.keys() files.sort() def name(base, f): if f: path = os.path.join(base, f) else: path = base # interdiff requires two files; use /dev/null if one is missing. if os.path.exists(path): return path return '/dev/null' ret = 0 for f in files: if os.system('icdiff "%s" "%s"' % (name(sys.argv, f), name(sys.argv, f))): ret = 1 sys.exit(ret)
Next, we want this to be piped into
less for easy paging, so put the following code in
~/scripts/hg-icdiff-wrapper, and also
chmod +x it. The
-F parameter makes
less not page if the output fits in the screen.
$HOME/scripts/hg-icdiff "$@"|less -F -X
3. Mercurial settings
Next, lets configure Mercurial so that it knows about our script. Add the following to your
~/.hgrc (note the absolute path; I was not able to get it working with tilde
[extensions] extdiff= [extdiff] cmd.icdiff=/home/iano/scripts/hg-icdiff-wrapper
You can now replace
diff in your Mercurial commands with
icdiff, and it will do a side-by-side diff instead of inline.
hg icdiff is too long, add the following aliases to your
# side-by-side diffs for uncommitted files alias ic='hg icdiff' # diff all changes since the base revision, including uncommitted # (from master if you are using bookmarks, for example) alias ica='hg icdiff -r .^' # diff the existing changes, excluding uncommitted alias ice='hg icdiff --ch .'