Technical Reference: Kernel and Subsystems, Volume 1

fp_lseek, fp_llseek Kernel Service

Changes the current offset in an open file.

#include <sys/types.h>
#include <sys/errno.h>

int fp_lseek ( fp, offset, whence) struct file *fp; off_t offset; int whence;

int fp_llseek ( fp, offset, whence) struct file *fp offset_t offset; int whence;

fp	Points to a file structure returned by the fp_open kernel service.
offset	Specifies the number of bytes (positive or negative) to move the file pointer.
whence	Indicates how to use the offset value: SEEK_SET Sets file pointer equal to the number of bytes specified by the offset parameter. SEEK_CUR Adds the number of bytes specified by the offset parameter to current file pointer. SEEK_END Adds the number of bytes specified by the offset parameter to current end of file.

The fp_lseek and fp_llseek kernel services are internal interfaces to the function provided by the lseek and llseek subroutines.

The fp_lseek and fp_llseek kernel services can be called from the process environment only.

0	Indicates a successful operation.
ERRNO	Returns an error number from the /usr/include/sys/errno.h file on failure.

The lseek, llseek subroutine.

Logical File System Kernel Services in AIX 5L Version 5.2 Kernel Extensions and Device Support Programming Concepts.