Moves the read-write file pointer.
off_t lseek (FileDescriptor, Offset, Whence) int FileDescriptor, Whence; off_t Offset;
offset_t llseek (FileDescriptor, Offset, Whence) int FileDescriptor, Whence; offset_t Offset;
Note: The lseek64 subroutine applies to Version 4.2 and later releases.
off64_t lseek64 (FileDescriptor, Offset, Whence) int FileDescriptor, Whence; off64_t Offset;
Note: The lseek64 subroutine applies to Version 4.2 and later releases.
The lseek, llseek, and lseek64 subroutines set the read-write file pointer for the open file specified by the FileDescriptor parameter. The lseek subroutine limits the Offset to OFF_MAX.
In AIX Version 4.1, the llseek subroutine limits the Offset to OFF_MAX if the file associated with FileDescriptor is a regular file or a directory and to DEV_OFF_MAX if the file associated with FileDescriptor is a block special or character special file.
In Version 4.2, both the llseek subroutine and the lseek64 subroutine limit the Offset to the maximum file size for the file size for the file associated with FileDescriptor and to DEV_OFF_MAX if the file associated with FileDescriptor is a block special or character special file.
In the large file enabled programming environment, lseek subroutine is redefined to lseek64.
Upon successful completion, the resulting pointer location, measured in bytes from the beginning of the file, is returned. If either the lseek or llseek subroutines are unsuccessful, a value of -1 is returned and the errno global variable is set to indicate the error.
The lseek or llseek subroutines are unsuccessful and the file pointer remains unchanged if any of the following are true:
This subroutine is part of Base Operating System (BOS) Runtime.
/usr/include/unistd.h | Defines standard macros, data types and subroutines. |
The fcntl subroutine, fseek, rewind, ftell, fgetpos, or fsetpos subroutine, open, openx, or creat subroutine, read, readx, readv, or readvx subroutine, write, writex, writev, or writevx subroutine.
Files, Directories, and File Systems for Programmers in AIX Version 4.3 General Programming Concepts: Writing and Debugging Programs.