Re: libtrivfs/glibc questions

[Neal H Walfield]

> Sorry, i still don't understand this.
> 
> If i do a normal read() on a Trivfs translator, trivfs_S_io_read in my
> translator gets called. OK. But, in the read() call, i haven't
> specified a datalen. Now, at which point does this datalen parameter
> get "created"?
> 
> I guess, it's a quiet silly question. I just don't understand yet how
> all these things interact with each other..

You fill it in based on the amount _actually_ read.  For instance, amount
is 1024, the file size is 4096 there are 256 bytes until the end of file.
You would:

if (po->pos + amount > po->filesize)
  amount = po->filesize - po->pos;

memcpy (data, file_buffer + po->pos, amount);
*datalen = amount;

-Neal

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