llseek(2) System Calls llseek(2)
llseek - move extended read/write file pointer
offset_t llseek(int fildes, offset_t offset, int whence);
The llseek() function sets the 64-bit extended file pointer associated
with the open file descriptor specified by fildes as follows:
o If whence is SEEK_SET, the pointer is set to offset bytes.
o If whence is SEEK_CUR, the pointer is set to its current location
o If whence is SEEK_END, the pointer is set to the size of the file
Although each file has a 64-bit file pointer associated with it, some
existing file system types (such as tmpfs) do not support the full
range of 64-bit offsets. In particular, on such file systems, non-
device files remain limited to offsets of less than two gigabytes.
Device drivers may support offsets of up to 1024 gigabytes for device
Some devices are incapable of seeking. The value of the file pointer
associated with such a device is undefined.
Upon successful completion, llseek() returns the resulting pointer
location as measured in bytes from the beginning of the file. Remote
file descriptors are the only ones that allow negative file pointers.
Otherwise, -1 is returned, the file pointer remains unchanged, and
errno is set to indicate the error.
The llseek() function will fail if:
EBADF The fildes argument is not an open file descriptor.
EINVAL The whence argument is not SEEK_SET, SEEK_CUR, or
SEEK_END; the offset argument is not a valid offset for
this file system type; or the fildes argument is not a
remote file descriptor and the resulting file pointer
would be negative.
ESPIPE The fildes argument is associated with a pipe or FIFO.
creat(2), dup(2), fcntl(2), lseek(2), open(2)
SunOS 5.10 6 Jan 1999 llseek(2)