NAME    [Toc]    [Back]

     fgetpos, fseek, fseeko, fsetpos,  ftell,  ftello,  rewind  -
reposition a
     stream

SYNOPSIS    [Toc]    [Back]

     #include <stdio.h>

     int
     fgetpos(FILE *stream, fpos_t *pos);

     int
     fseek(FILE *stream, long offset, int whence);

     int
     fseeko(FILE *stream, off_t offset, int whence);

     int
     fsetpos(FILE *stream, const fpos_t *pos);

     long
     ftell(FILE *stream);

     off_t
     ftello(FILE *stream);

     void
     rewind(FILE *stream);

DESCRIPTION    [Toc]    [Back]

     The  fseek()  function  sets the file position indicator for
the stream
     pointed to by stream.  The new position, measured in  bytes,
is obtained
     by  adding offset bytes to the position specified by whence.
If whence is
     set to SEEK_SET, SEEK_CUR, or SEEK_END, the offset is  relative to the
     start  of  the file, the current position indicator, or endof-file, respectively.
  A  successful  call  to  the  fseek()  function
clears the end-offile
  indicator for the stream and undoes any effects of the
ungetc(3)
     function on the same stream.

     The fseeko() function is identical to fseek() except that it
takes an
     off_t as its offset.

     The  ftell()  function obtains the current value of the file
position indicator
 for the stream pointed to by stream.

     The ftello() function is identical to  ftell()  except  that
its return value
 is of type off_t.

     The  rewind()  function sets the file position indicator for
the stream
     pointed to by stream to the beginning of the  file.   It  is
equivalent to:

           (void)fseek(stream, 0L, SEEK_SET)

     except  that  the  error  indicator  for  the stream is also
cleared (see
     clearerr(3)).

     The fgetpos() and fsetpos() functions are  alternate  interfaces equivalent
     to  ftell()  and fseek() (with whence set to SEEK_SET), setting and storing
     the current value of the file offset into or from the object
referenced
     by pos.  On some (non-UNIX) systems an ``fpos_t'' object may
be a complex
     object and these routines may be the only  way  to  portably
reposition a
     text stream.

RETURN VALUES    [Toc]    [Back]

     The  rewind()  function  returns  no value.  Upon successful
completion,
     fgetpos(), fseek(), fseeko(), fsetpos() return 0 and ftell()
and ftello()
     return  the current offset.  Otherwise, fseek() and fseeko()
return -1 and
     the others return a nonzero value and  the  global  variable
errno is set to
     indicate the error.

ERRORS    [Toc]    [Back]

     [EBADF]       The stream specified is not a seekable stream.

     [EINVAL]       The  whence  argument  to  fseek()  was   not
SEEK_SET, SEEK_END,
                   or SEEK_CUR.

     The   function   fgetpos(),  fseek(),  fseeko(),  fsetpos(),
ftell(), and
     ftello() may also fail and set errno for any of  the  errors
specified for
     the routines fflush(3), fstat(2), lseek(2), and malloc(3).

SEE ALSO    [Toc]    [Back]

     lseek(2)

STANDARDS    [Toc]    [Back]

     The  fgetpos(),  fsetpos(),  fseek(),  ftell(), and rewind()
functions conform
 to ANSI X3.159-1989 (``ANSI C'') and X/Open Portability
Guide Issue
     4 (``XPG4'').

     The fseeko() and ftello() functions conform to X/Open Portability Guide
     Issue 4 (``XPG4'').

OpenBSD     3.6                        February     21,      2000