Repositioning an ostream

You can control the output position (on output streams that actually support positions, typically files) with these methods:

Method: streampos ostream::tellp ()

Return the current write position in the stream.

Method: ostream& ostream::seekp (streampos loc)

Reset the output position to loc (which is usually the result of a previous call to ostream::tellp). loc specifies an absolute position in the output stream.

Method: ostream& ostream::seekp (streamoff loc, rel)

Reset the output position to loc, relative to the beginning, end, or current output position in the stream, as indicated by rel (a value from the enumeration ios::seekdir):

beg

Interpret loc as an absolute offset from the beginning of the file.

cur

Interpret loc as an offset relative to the current output position.

end

Interpret loc as an offset from the current end of the output stream.