Better error messages for command not found (was Re: Pull in upstream before 9.1 code freeze?)

[Tim Kientzle]

On Jul 4, 2012, at 4:41 PM, Jason Hellenthal wrote:
> 
> On Wed, Jul 04, 2012 at 03:59:29PM -0700, Doug Barton wrote:
>> On 07/04/2012 15:55, Jason Hellenthal wrote:
>>> Seeing as sudo plays a big part of this
>> 
>> No ... not only is sudo not a necessary component, it shouldn't be
>> involved at all. The feature works on debian/ubuntu for regular
>> userspace commands.
>> 
> 
> What are they using to authenticate for the install ? do you know ?

Huh?  What install?  Who's talking about install?

The version of this I've seen looks like this:

$ svn co https://some.url/
svn: Command not found.
  To use this command, install one of the following packages:
      devel/subversion
      devel/subversion-freebsd
      devel/subversion16

That's all it does:  It just prints out a more informative error message.
It does not install anything, it requires no special permissions,
and does not (as far as I can see) introduce any security or
performance problems.

The implementation is pretty simple:
 * A tool for building a database that maps command names
   to package names.  (This would run against a ports tree or
   package repository.  Conceptually, it's pretty similar to
   how port/package indexes get built today.)
 * Some way to distribute that database (Probably as part of ISO
   releases, maybe extend 'portsnap' or 'pkg_add' to update it?)
 * A program to look up command names in that database
   and print out the results.
 * A shell hook to run said program whenever a "command not found"
   error occurs.

As a first prototype, the database could just be a text file
and the look up program could be a shell script that uses
grep and sed.

Tim