Implement support for listing a generation in kdirstat.cache format

On Sat, 2014-12-06 at 19:15 +0200, Lars Wirzenius wrote:
> On Sun, Nov 16, 2014 at 11:24:11AM +0000, Ian Campbell wrote:
> > This implements an ls variant whose output format is compatible with the
> > kdirstat cache format. The best reference I can find for this is from an old fork:
> > https://github.com/thomas-joiner/k4dirstat/blob/master/kdirstat/cache-file-format.txt
> >
> > Recent versions of k4dirstat appear to be able to read the files produced just
> > fine, although this document is not present in their source AFAICT.
> >
> > I find k4dirstat to be an excellent way to visualise what is included in a
> > backup, e.g. for the purposes of excluding file types or marking directories
> > with a CACHEDIR.TAG. My previous solution involved post-processing the output
> > of ls which require a ssh to the machine with the files (for stat() purposes).
> > This approach pulls all of the data out of the obnam repo, so is much faster,
> > less hacky and gets the status of the actual generation and not the current
> > files etc.
>
> Thank you, Ian. I've applied the patch and pushed the changes to
> master on git.liw.fi.

Thanks.

> It would be nice if someone wrote a test case for this (in yarn form),
> so that I'll notice when I break it.

Your wish etc etc... (it even found a bug!)

8<----------------

>From 8f1aecfee8ec34e5d060f81ee47f9fd8aacdc201 Mon Sep 17 00:00:00 2001
From: Ian Campbell <ijc@hellion.org.uk>
Date: Sun, 7 Dec 2014 15:19:57 +0000
Subject: [PATCH] Add a yarn for testing kdirstat cachefile generation.

Rather simplistic, but caught one bug (unwanted newline at start of file) which
is also fixed here.

1 files changed, 1 insertions, 2 deletions

diff --git a/obnamlib/plugins/show_plugin.py b/obnamlib/plugins/show_plugin.py
index 9114f309..5e28fed2 100644
--- a/obnamlib/plugins/show_plugin.py
+++ b/obnamlib/plugins/show_plugin.py
@@ -264,8 +264,7 @@ class ShowPlugin(obnamlib.ObnamPlugin):
         self.traverse(self.show_hdr_kdirstat, self.show_item_kdirstat, args)
 
     def show_hdr_kdirstat(self, comment):
-        self.app.output.write('''
-[kdirstat 4.0 cache file]
+        self.app.output.write('''[kdirstat 4.0 cache file]
 # Generated by obnam %s
 # Do not edit!
 #