Identifying bundles in MacOS X

[Michael J. Fromberger]

In article <2vt7veF2nues7U1 at uni-berlin.de>,
 Greg Ewing <greg at cosc.canterbury.ac.nz> wrote:

> Michael J. Fromberger wrote:
> > Given the pathname of a directory in my filesystem, I would like a 
> > graceful way to determine whether or not that directory represents 
> > a "bundle", in the sense that, when you double-click on the 
> > directory's icon in the Finder, it is launched rather than "opened" 
> > for viewing. Applications behave this way by default, but so do 
> > various other file types (e.g., the "rtfd" files created by 
> > TextEdit, and the data files for certain applications such as 
> > Quicken).
> 
> I think that a MacOSX-style application can be recognised simply by 
> the fact that it's a directory whose name ends in ".app". (You don't 
> usually see that extension in the Finder, but all MacOSX application 
> bundles seem to have it.)

Actually, Apple's developer documentation seems to imply that there is a 
"bundle bit" in the Finder info (or possibly the extended Finder info) 
for directories, and that if this bit is set, the Finder will treat the 
folder as a bundle.  At any rate, there are many bundle-like directories 
other than just ".app" files and old-style 'APPL' type files.  The 
trouble is, the Carbon.File module does not seem to expose the 
appropriate fields of the FSCatalogInfo structure from the Carbon API, 
so I can't get at that bit from within Python.

I found and adapted a patch to Mac/Modules/file/_Filemodule.c, that 
makes the finderInfo and finderXInfo fields visible, but either I did it 
wrongly, or there is some other issue I've missed, for I get nothing but 
an empty FInfo structure back when I try to access either of them.

I guess my next step should be to write a C program against the Carbon 
API, and see if I can get the information that way -- if so, I guess I 
will just have to patch the Carbon.File module myself.  If not, I might 
have to admit defeat for now.

Meanwhile, I'm using a workaround, a.k.a. a gross hack:  If the 
directory's name has one of a set of "known" extensions, or if it 
contains a directory named "Contents", and if it doesn't have more than 
a few files at its top level apart from the "Contents" directory, I'm 
considering it a bundle.  That works well enough for my purposes, but 
I'd really rather have it work "correctly."

Thanks for taking the time to write back!

Cheers,
-M

-- 
Michael J. Fromberger             | Lecturer, Dept. of Computer Science
http://www.dartmouth.edu/~sting/  | Dartmouth College, Hanover, NH, USA