- reposition a file pointer in a stream
#include <stdio.h> int fsetpos(FILE *stream, const fpos_t *pos);
The fsetpos() function sets the file position indicator for the stream pointed to by stream according to the value of the object pointed to by pos, which must be a value obtained from an earlier call to fgetpos(3C) on the same stream.
A successful call to fsetpos() function clears the end-of-file indicator for the stream and undoes any effects of ungetc(3C) on the same stream. After an fsetpos() call, the next operation on an update stream may be either input or output.
The fsetpos() function returns 0 if it succeeds; otherwise it returns a non-zero value and sets errno to indicate the error.
The fsetpos() function may fail if:
The file descriptor underlying stream is not valid.
The file descriptor underlying stream is associated with a pipe, a FIFO, or a socket.
The fsetpos() function has a transitional interface for 64-bit file offsets. See lf64(5).
See attributes(5) for descriptions of the following attributes: