lseek(2)                                                 lseek(2)



     NAME
          lseek - move read/write file pointer

     SYNOPSIS
          #include <sys/types.h>

          #include <unistd.h>

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

     DESCRIPTION
          The file descriptor fildes is returned from a creat, open,
          dup, or fcntl system call.  lseek sets the file pointer as-
          sociated with fildes as follows:

          If whence is 0, the pointer is set to offset bytes.

          If whence is 1, the pointer is set to its current location
          plus offset.

          If whence is 2, the pointer is set to the size of the file
          plus offset.

          In the POSIX environment, the following values are defined
          in <unistd.h> for passing as the value of whence:

          SEEK_SET  0

          SEEK_CUR  1

          SEEK_END  2

          On successful completion, the resulting pointer location, as
          measured in bytes from the beginning of the file, is re-
          turned.

     RETURN VALUE
          On successful completion, a non-negative integer indicating
          the file pointer value is returned.  Otherwise, a value of
          -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.




     April, 1990                                                     1

     lseek(2)                                                 lseek(2)



          [EINVAL]       whence is not 0, 1, or 2.

          [EINVAL]       The resulting file pointer would be negative.

          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).














































     2                                                     April, 1990