_llseek - reposition read/write file offset
_syscall5(int, _llseek, uint, fd, ulong, hi,
int _llseek(unsigned int fd, unsigned long offset_high,
unsigned long offset_low
The _llseek function repositions the offset of the file
descriptor fd to (offset_high<<32) | offset_low bytes rela-
tive to the beginning of the file, the current position in
the file, or the end of the file, depending on whether
whence is SEEK_SET, SEEK_CUR, or SEEK_END, respectively. It
returns the resulting file position in the argument result.
Upon successful completion, _llseek returns 0. Otherwise, a
value of -1 is returned and errno is set to indicate the
fd is not an open file descriptor.
whence is invalid.
This function is Linux-specific, and should not be used in
programs intended to be portable.
The ext2 filesystem does not support files with a size of
2GB or more.