CFT: new BSD-licensed sort available
oleg.moskalenko at citrix.com
Thu Mar 15 01:19:44 UTC 2012
This is true, debians do the symlinks trick.
In Ubuntu :
/usr/bin/java -> /etc/alternatives/java
/etc/alternatives/java - >/usr/lib/jvm/java-6-openjdk/jre/bin/java
From: Jonathan Anderson [mailto:jonathan.anderson at cl.cam.ac.uk]
Sent: Wednesday, March 14, 2012 3:14 PM
To: Adrian Chadd
Cc: Gabor Kovesdan; freebsd-current at freebsd.org; Oleg Moskalenko; freebsd-ports at freebsd.org
Subject: Re: CFT: new BSD-licensed sort available
On 14 Mar 2012, at 21:10, Adrian Chadd wrote:
This makes me think of the whole debian-y way of replacing the mailer
programs using some magic alias program.
So you could intall gnusort, bsdsort, and then some config file would
determine which was used.
'sort' would then be a symlink to said magic program, that'd look at
its argv, look at the contents of that file, and exec() the right
In fact, the runtime behaviour of the Debian "alternatives" system is simpler than that:
The custom Perl script with a config file is used to set up symlinks, which at runtime are... well, just symlinks. For instance, /usr/bin/vim is a symlink to /etc/alternatives/vim, which is itself a symlink to a binary like vim.gtk (example shamelessly stolen from the linked page, since I no longer have any Debian boxes to check for myself on :). No magic binaries or argv fu.
In one way, it's an elegant solution. On the other, it's a classic example of Wheeler's Law in action. :)
Research Student, Security Group
University of Cambridge
+44 (1223) 763747
jonathan.anderson at cl.cam.ac.uk<mailto:jonathan.anderson at cl.cam.ac.uk>
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