Hi, On Sat, Sep 7, 2013 at 6:44 PM, Marco Schuster <ma...@m-s-d.eu> wrote:
> > I ran into 32-bit problems, too, when working with >2GB files (in this > case, raw DVD ISO images) on a 32-bit system (I couldn't find a > reliable(!!) way to read a 4-byte absolute offset and seek to it). > Of course, this warning is mentioned in the manpage, but really, not > having at least a class for unsigned 32-bit ints (e.g. a Uint32 or a > Uint64 for 64-bit platforms) which native functions like seek and > friends coerce into a 32/64-bit uint makes PHP useless for anything > that involves access to files or memory offsets (a problem from > another project) > 2GB. > > The seek offset is always signed. In C you have either int fseek (FILE *stream, long int offset, int whence) which is signed. Or you can use int fseeko (FILE *stream, off_t offset, int whence) or off_t lseek(int fd, off_t offset, int whence) for descriptors. When you look to glibc, you will find these definitions #define __OFF_T_TYPE __SYSCALL_SLONG_TYPE __STD_TYPE __OFF_T_TYPE __off_t; typedef __off_t off_t; __SYSCALL_SLONG_TYPE is signed type as well (S Long :)). If you need to seek over 31bit size on 32bit system, then you can seek twice. Just need to set the whence to SEEK_CUR for the second seek... Jakub
