LSEEK(2-SVR3)       RISC/os Reference Manual        LSEEK(2-SVR3)



NAME
     lseek - move read/write file pointer

SYNOPSIS
     #include <unistd.h>
     #include <sys/types.h>

     offt lseek (fildes, offset, whence)
     int fildes;
     offt offset;
     int whence;

DESCRIPTION
     fildes is a file descriptor returned from a creat, open,
     dup, or fcntl system call.  lseek sets the file pointer
     associated with fildes as specified by the value of the
     argument whence.  Symbolic constants for whence are defined
     in <unistd.h> as follows:

     SEEKSET       the pointer is set to offset bytes.

     SEEKCUR       the pointer is set to its current location
                    plus offset.

     SEEKEND       the pointer is set to the size of the file
                    plus offset.

RETURN VALUE
     Upon successful completion, the resulting pointer location,
     as measured in bytes from the beginning of the file, is
     returned.  Otherwise, ((off_t)-1) is returned and errno is
     set to indicate the error.

ERRORS
     lseek will fail and the file pointer will remain unchanged
     if one or more of the following are true:

     [EBADF]                       fildes is not an open file
                                   descriptor.

     [ESPIPE]                      fildes is associated with a
                                   pipe or fifo.

     [EINVAL and SIGSYS signal]    whence is not SEEKSET,
                                   SEEKCUR, or SEEKEND.

     Some devices are incapable of seeking.  The value of the
     file pointer associated with such a device is undefined.

SEE ALSO
     creat(2), dup(2), fcntl(2), open(2).




                        Printed 11/19/92                   Page 1