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 Oleg From: Jonathan Anderson [mailto:jonathan.ander...@cl.cam.ac.uk] Sent: Wednesday, March 14, 2012 3:14 PM To: Adrian Chadd Cc: Gabor Kovesdan; freebsd-current@freebsd.org; Oleg Moskalenko; freebsd-po...@freebsd.org Subject: Re: CFT: new BSD-licensed sort available On 14 Mar 2012, at 21:10, Adrian Chadd wrote: Hi, 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[0], look at the contents of that file, and exec() the right one. In fact, the runtime behaviour of the Debian "alternatives" system is simpler than that: http://segfault.in/2010/04/using-the-debian-alternatives-system/ 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[0] fu. In one way, it's an elegant solution. On the other, it's a classic example of Wheeler's Law in action. :) Jon -- Jonathan Anderson Research Student, Security Group Computer Laboratory University of Cambridge +44 (1223) 763747 jonathan.ander...@cl.cam.ac.uk<mailto:jonathan.ander...@cl.cam.ac.uk> _______________________________________________ freebsd-current@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"
