Toon Moene wrote: > Now an interesting question is how we are going to treat this with > gfortran: On the one hand we can do it right (use one record length > size on 32-bit and 64-bit systems), but then people on 64-bit systems > can't read their g77 generated unformatted files - or we could do the > same as libf2c and be stuck with the above problem. > > On the third hand, I have received requests for 64-bit record lengths > on either system so that larger-than-2-Gbyte records are possible. > as of right now, the gfortran approach is like this: each sequential, unformatted record is prefixed with a byte count, of type off_t. off_t is a 64 bit number on FreeBSD and is a 32 bit number on Linux (without using the LFS routines). sequential, unformatted I/O is also broken, the lower level write routine that spaces back to write this byte count doesn't work; these facts are only marginally applicable to this discussion:=) i like the idea that the default is 64 bits for either case, but for users with an off_t of only 32 bits, they would be restricted to a record size < 2^32. the run-time could give an error message "unformatted record size too big" or something. this of course means you cannot read g77 unformatted files. --bud davis
