Nicolas Alvarez wrote:

>> Unlike UNIX, it's not just a matter of seeking around. You have to 
>> open the file as a sparse file, then you have to say "hey, this area 
>> is sparse" rather than (say) just writing all zeros to the blocks or 
>> something.
> 
> Not really... Cross-platform programs that don't use any 
> Windows-specific API manage to create sparse files here.

I think if you write to it, regardless of what you write, you get 
allocated space. UNIX *used* to see an all-zeros buffer and say "Gee, we 
don't need to write that."  You didn't have to seek over the sparse 
space to make it sparse, IIRC.

I think the calls I'm thinking of are for making an existing data area 
sparse, too; i.e., throwing away the beginning of a log file without 
changing offsets of existing records. And you may even need to open the 
file in "sparse" mode.

Or, I could be completely wrong. This one I never actually did. :-)

-- 
   Darren New / San Diego, CA, USA (PST)
     Remember the good old days, when we
     used to complain about cryptography
     being export-restricted?

Post a reply to this message