[Pythonmac-SIG] AppleEvents in MacPython 2.3?

[Jack Jansen]

On woensdag, aug 13, 2003, at 07:57 Europe/Amsterdam, Larry Meyn wrote:

> My thanks to Mark and Bob for their help.  I've thrown together the 
> following crude function to generate OS 9 style path names under OS X 
> for a scriptable application that needs them.
>
>
> def makeOS9abspath(path):
> 	"""Returns an ":" delimited, OS 9 style absolute path.
> 	"""
> 	import Carbon.File, os.path
> 	
> 	abspath = os.path.abspath(path)
> 	rootdisk = Carbon.File.FSRef('/').FSGetCatalogInfo(0)[2].as_tuple()[2]
> 	abspath = rootdisk + ":".join(abspath.split('/')) #make ':' delimited
>
> 	if os.path.isdir(path):
> 		return abspath + ":"  #add trailing ':' for directories
> 	else:
> 		return abspath

This will work for 90% of the paths, but fail on all sorts of 
exceptional
ones. Some of the problems:
- It doesn't handle ':' in unix filenames (should be converted to /)
- It only handles 7-bit ascii (unix filenames use utf8 encoding, OS9 
paths
   use MacRoman or another encoding)
- It will fail for filenames longer than 32 (or 31) characters


What you should do is create an FSSpec for the file, and recursively get
the pathname components from it. Here it is:

def makeOS9abspath(path):
	"""Returns an ":" delimited, OS 9 style absolute path.
	"""
	import Carbon.File, os.path
	
	rv = []
	fss = Carbon.File.FSSpec(path)
	while 1:
		vrefnum, dirid, filename = fss.as_tuple()
		rv.insert(0, filename)
		if dirid == 1: break
		fss = Carbon.File.FSSpec((vrefnum, dirid, ""))
	if len(rv) == 1:
		rv.append('')
	return ':'.join(rv)

This one still has a problem in that it will not work if path doesn't 
yet
exist, on OSX FSSpec(path) goes via FSRef's, and these are only defined 
on
existing files. The bad news is that I don't think there is a 100% 
failsafe
way to create an OS9 path for a nonexisting item on OSX (given a UTF8 
unix
path).
--
- Jack Jansen        <Jack.Jansen at oratrix.com>        
http://www.cwi.nl/~jack -
- If I can't dance I don't want to be part of your revolution -- Emma 
Goldman -