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2004.09.17 22:15 "Re: BigTIFF Tag Value Count issue", by Bob Friesenhahn
On Fri, 17 Sep 2004, Ross A. Finlayson wrote: > > I agree with Fernando, et al., that "Baseline" BigTIFF or so only require > 63 of 64 bits in offset with file size support to 2^63-1. Any software is > obviously free to support 64 bits in the 64 bit offset, but actually as > some system file APIs such as UNIX do use signed offsets, those that don't > should still offer relatively uncomplicated standard conformance. This is a reasonable argument. For Solaris 9, when large files are supported these are the basic types: size_t unsigned 64 bits - size of something in bytes ssize_t signed 64 bits - size of something in bytes or -1 off_t signed 64 bits - offsets within files The ftruncate() and lseek() functions accept off_t arguments and lseek() returns off_t. Therefore the useable file size is indeed currently constrained to 63 bits. Just as we are getting used to 64 bit file offsets, Solaris 10 is introducing a file system (zfs) which supports 128 bit offsets. :-) Bob ====================================== Bob Friesenhahn bfriesen@simple.dallas.tx.us http://www.simplesystems.org/users/bfriesen