FSEEK(3)		   Linux Programmer's Manual		      FSEEK(3)



NAME
       fgetpos, fseek, fsetpos, ftell, rewind - reposition a stream

SYNOPSIS
       #include <stdio.h>

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

       long ftell(FILE *stream);

       void rewind(FILE *stream);

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

DESCRIPTION
       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 end-of-file,
       respectively.  A successful call to the	fseek()	 function  clears  the
       end-of-file  indicator  for  the	 stream	 and undoes any effects of the
       ungetc(3) function on the same stream.

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

       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  equiva-
       lent  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 repo-
       sition a text stream.

RETURN VALUE
       The  rewind()  function	returns no value.  Upon successful completion,
       fgetpos(), fseek(), fsetpos() return 0, and ftell() returns the current
       offset.	 Otherwise,  -1	 is  returned and errno is set to indicate the
       error.

ERRORS
       EBADF  The stream specified is not a seekable stream.

       EINVAL The whence argument to fseek() was not  SEEK_SET,	 SEEK_END,  or
	      SEEK_CUR.	 Or: the resulting file offset would be negative.

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

ATTRIBUTES
       For   an	  explanation	of   the  terms	 used  in  this	 section,  see
       attributes(7).

       +----------------------------+---------------+---------+
       |Interface		    | Attribute	    | Value   |
       +----------------------------+---------------+---------+
       |fseek(), ftell(), rewind(), | Thread safety | MT-Safe |
       |fgetpos(), fsetpos()	    |		    |	      |
       +----------------------------+---------------+---------+

CONFORMING TO
       POSIX.1-2001, POSIX.1-2008, C89, C99.

SEE ALSO
       lseek(2), fseeko(3)

COLOPHON
       This page is part of release 4.10 of the Linux  man-pages  project.   A
       description  of	the project, information about reporting bugs, and the
       latest	 version    of	  this	  page,	   can	   be	  found	    at
       https://www.kernel.org/doc/man-pages/.



GNU				  2015-08-08			      FSEEK(3)