Re: How to get the directory of a package?

[Eric Abrahamsen]

Marcin Borkowski <mbork@mbork.pl> writes:

> OK,
>
>> assume that I'm writing a package which wants to use a file from the
>> same directory the .el (or .elc) file of the package is located in.  How
>> can the package know where in the filesystem it is located?
>>
>> Bonus points for a method which works not only with `require', but also
>> with `load-file' and `eval-buffer' (in the last case,
>> `default-directory' will probably work, but I skimmed through all
>> variables and functions matching `directory$' and nothing seemed to be
>> what I'm looking for).
>
> so I think I've found the answer.  Is this correct?  Are there possibly
> some edge cases I didn't think about?
>
> (if load-file-name
>     (file-name-directory load-file-name)
>   default-directory)

I stole the following bit of code to find "this file" from 'ert-x, it
was a bit of cargo-culting as I'm not entirely sure when/how the various
conditions would be true:

(or (bound-and-true-p byte-compile-current-file)
    (and load-in-progress load-file-name)
    buffer-file-name)

Might be helpful?