Add a file flag for "hidden" files?

Mark Day mday at apple.com
Thu Mar 2 09:45:47 PST 2006


On Mar 1, 2006, at 10:22 AM, Robert Watson wrote:

> You can find current flag allocation here:
>
>   http://fxr.watson.org/fxr/source/sys/stat.h

The obvious (to me) choice for UF_HIDDEN would be 0x00000040 (leaving  
0x00000020 unused as the user flag corresponding to SF_SNAPSHOT).   
But would anyone object to using 0x00008000 (the most significant bit  
of the user flags)?

The reason I ask is because HFS Plus only stores 16 bits of file  
flags on disk (lower 8 bits of user flags plus lower 8 bits of super- 
user flags).  We're getting close to running out of the lower 8 bits,  
and HFS Plus has a different place it can store UF_HIDDEN (the  
"invisible" bit of the Finder Info).  There's a side bonus, too,  
because the UF_HIDDEN and "invisible" bits can't get out of sync if  
the UF_HIDDEN flag isn't actually being stored on disk.  In the Mac  
OS X sources, I already have code in HFS to propagate the "invisible"  
bit to UF_HIDDEN and vice versa to make sure they always appear  
consistent (if either one is set, then both are set).

Or would you prefer I use 0x00000020 since there is no user flag  
equivalent of SF_SNAPSHOT?

-Mark



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