HP C/iX Library Reference Manual (30026-90004)

240 Chapter5
HP C/iX Library Function Descriptions
lseek
lseek
Moves the file position indicator.
Syntax
#include <unistd.h>
long lseek (int fildes , long offset , int whence );
Parameters
filedes An open file descriptor.
offset The number of bytes to move the current file position indicator, according
to the method defined by
whence .
whence The starting point for the seek operation. The possible values are:
SEEK_SET Seek relative to the beginning of file.
SEEK_CUR Seek relative to the current location in the file.
SEEK_END Seek relative the end of file.
Return Values
≥0 The resulting file position indicator location, as measured in bytes from
the beginning of the file.
−1 An error occurred and errno is set to one of the following values:
EBADF The
fildes parameter is not an open file descriptor.
EINVAL The
whence parameter is not 0, 1 or 2.
EINVAL The resulting file position indicator would be negative.
ESEEK The
fildes parameter does not refer to a file that
supports seeking.
ESYSERR A call to a system intrinsic failed.
Description
The lseek function repositions the file position indicator associated with fildes .
Some devices are incapable of seeking. The value of the file position indicator associated
with such a device is undefined.
NOTE If linking with the POSIX/iX library, refer to the description of lseek()
located in the MPE/iX Developer's Kit Reference Manual.