[OS X TeX] the /usr directory

[Art Werschulz]

Hi.

// Subject header renamed, to prevent subject-creep.

On Nov 3, 2014, at 11:21 PM, Ettore Aldrovandi <ealdrov at mail.math.fsu.edu> wrote:

> On Nov 3, 2014, at 20:50, Herbert Schulz <herbs at wideopenwest.com> wrote:
>> 
>> I guess I don't know why a directory named /usr shouldn't be useful for stuff that is used by all users of a system.
> 
> Because it is owned by the operating system; updates, etc. do not expect to find user-defined stuff in that location, or /, for that matter. So if you put things under, say, the /usr tree, there is no guarantee that it will be survive an update or upgrade unscathed. System installers don’t check because those places are their playground [1]. There are global subtrees which have been reserved for such purposes, the most (in)famous being of course /usr/local, but there are others: /Library (and notice: not /System/Library) and /Applications, if we stick to OS X, but more generally on UNIX-like systems /opt a common choice, where a relatively large package would create a subtree /opt/<package-name>.  This is why I think /usr/texbin is a poor choice from a system engineering point of view.

In real life, I'm a Comp Sci professor at Fordham University.  We run Linux on all the Departmental machines at our campus (Lincoln Center, not the Bronx).  To get around the problem Ettore mentions, /usr/local is on a separate partition.  Ditto with /home (analogous to /Users on Mac OS X).  If we need to do a clean install, the installer can be told to respect these two partitions.  

Art Werschulz
agw at comcast.net