FSEEK(3) Linux Programmer's Manual FSEEK(3)
fgetpos, fseek, fsetpos, ftell, rewind - reposition a stream
SYNOPSIS top
#include <stdio.h>
int fseek(FILE *stream, long offset, int whence);
long ftell(FILE *stream);
void rewind(FILE *stream);
int fgetpos(FILE *restrict stream, fpos_t *restrict pos);
int fsetpos(FILE *stream, const fpos_t *pos);
DESCRIPTION top
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
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 VALUE top
