virtual streampos seekoff( streamoff off, ios::seek_dir dir,
int nMode = ios::in | ios::out );
off
The new offset value; streamoff is a typedef equivalent to long.
dir
The seek direction specified by the enumerated type seek_dir, as follows:
| Value | Meaning |
| ios::beg | Seek from the beginning of the stream. |
| ios::cur | Seek from the current position in the stream. |
| ios::end | Seek from the end of the stream. |
nMode
An integer that contains a bitwise-OR (|) combination of the enumerators ios::in and ios::out.
Changes the position for the streambuf object. Not all derived classes of streambuf need to support positioning; however, the filebuf, strstreambuf, and stdiobuf classes do support positioning.
Classes derived from streambuf often support independent input and output position values. The nMode parameter determines which value(s) is set.
Returns EOF.
The new position value. This is the byte offset from the start of the file (or string). If both ios::in and ios::out are specified, then the function returns the output position. If the derived class does not support positioning, then the function returns EOF.