_llseek(2) System Calls Manual _llseek(2) _llseek - / C (libc, -lc) #include /* SYS_* */ #include int syscall(SYS__llseek, unsigned int fd, unsigned long offset_high, unsigned long offset_low, loff_t *result, unsigned int whence); Note: glibc provides no wrapper for _llseek(), necessitating the use of syscall(2). Note: for information about the llseek(3) library function, see lseek64(3). The _llseek() system call repositions the offset of the open file description associated with the file descriptor fd to the value (offset_high << 32) | offset_low This new offset is a byte offset relative to the beginning of the file, the current file offset, or the end of the file, depending on whether whence is SEEK_SET, SEEK_CUR, or SEEK_END, respectively. The new file offset is returned in the argument result. The type loff_t is a 64-bit signed type. 32- . _llseek() . -1, errno , . EBADF fd . EFAULT . EINVAL whence . You probably want to use the lseek(2) wrapper function instead. Linux. lseek(2), open(2), lseek64(3) () Artyom Kunyov , Azamat Hackimov , Dmitry Bolkhovskikh , Katrin Kutepova , Konstantin Shvaykovskiy , Yuri Kozlov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () <>. Linux 6.9.1 2 2024 . _llseek(2)