_llseek − reposition read/write file offset
Standard C library (libc, −lc)
#include
<sys/syscall.h> /* Definition of SYS_*
constants */
#include <unistd.h>
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.
This system call exists on various 32-bit platforms to support seeking to large file offsets.
Upon successful completion, _llseek() returns 0. Otherwise, a value of −1 is returned and errno is set to indicate the error.
EBADF |
fd is not an open file descriptor. |
|||
EFAULT |
Problem with copying results to user space. |
|||
EINVAL |
whence is invalid. |
You probably want to use the lseek(2) wrapper function instead.
Linux.
lseek(2), open(2), lseek64(3)