LSEEK(2)                COMMAND REFERENCE                LSEEK(2)



NAME
     lseek - move read/write pointer

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

     pos = lseek(fd, offset, whence)
     int pos;
     int fd;
     offt offset;
     int whence;

DESCRIPTION
     Lseek sets the file pointer of the file referenced by fd,
     and returns the new value of the file pointer in pos. Fd
     refers to a file or device open for reading and/or writing.
     Whence is one of the following values, defined in
     <sys/file.h>:

          #define L_SET  0    /* set the seek pointer */
          #define L_INCR 1    /* increment the seek pointer */
          #define L_XTND 2    /* extend the file size */

     The use of offset is described below.

     Lseek sets the file pointer:

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

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

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

     Upon successful completion, the resulting pointer location
     as measured in bytes from beginning of the file is returned
     in pos . Some devices are incapable of seeking.  The value
     of the pointer associated with such a device is undefined.

     Seeking far beyond the end of a file, then writing, creates
     a gap or "hole", which occupies no physical space and reads
     as zeros.

DIAGNOSTICS
     Lseek will fail and the file pointer will remain unchanged
     if:

     [EBADF]      Fd is not an open file descriptor.

     [ESPIPE]     Fd is associated with a pipe or a socket.



Printed 4/6/89                                                  1

LSEEK(2)                COMMAND REFERENCE                LSEEK(2)



     [EINVAL]     Whence is not a proper value.

     [EINVAL]     The new pointer would be negative.

RETURN VALUE
     Upon successful completion, a non-negative integer pos, the
     current file pointer value, is returned.  Otherwise, a value
     of -1 is returned and errno is set to indicate the error.

CAVEATS
     This document's use of whence is incorrect English, but
     maintained for historical reasons.

SEE ALSO
     dup(2) and open(2).








































Printed 4/6/89                                                  2

%%index%%
na:264,83;
sy:347,1276;
de:1623,1575;
di:3198,368;3902,115;
rv:4017,334;
ca:4351,192;
se:4543,159;
%%index%%000000000132