rewind

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, fpos_t *pos);

DESCRIPTION

       The fseek function sets the file  position  indicator  for
       the  stream  pointed to by stream.  The new position, mea-
       sured 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
       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

       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
       the global variable 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.

       The  function  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).

SEE ALSO

       lseek(2)

STANDARDS

       The  fgetpos,  fsetpos, fseek, ftell, and rewind functions
       conform to ANSI C3.159-1989 (``ANSI C'').