- ls will sometimes yield a '@' in the file permissions string. This means that the file has extended attributes - a new feature of HFS
- Its supposed to be cool - you can add metadata to your files - that only Mac OS can understand - not so cool [here]
- Use xattr -d to get rid of these things, especially if you didn't put them there in the first place. e.g. xattr -d com.apple.metadata:kMDItemFinderComment IMG_7086.JPG
Python's context managers are a very neat way of handling code that needs a teardown once you are done. Python objects have do have a destructor method ( __del__ ) called right before the last instance of the object is about to be destroyed. You can do a teardown there. However there is a lot of fine print to the __del__ method. A cleaner way of doing tear-downs is through Python's context manager , manifested as the with keyword. class CrushMe: def __init__(self): self.f = open('test.txt', 'w') def foo(self, a, b): self.f.write(str(a - b)) def __enter__(self): return self def __exit__(self, exc_type, exc_val, exc_tb): self.f.close() return True with CrushMe() as c: c.foo(2, 3) One thing that is important, and that got me just now, is error handling. I made the mistake of ignoring all those 'junk' arguments ( exc_type, exc_val, exc_tb ). I just skimmed the docs and what popped out is that you need to return True or...
There is nothing wrong with extended attributes. Most Linux file systems got them as well. NTFS got them. OS/2's workplace shell was build around them.
ReplyDeleteThere serve a true need. They could replace the dreaded file extensions. Comments, Histrory, Display Names, Icons - all sorts of stuff can be handled by EAs
If only the various os vendors could agree on a single way of using them....