ofstream();
ofstream( const char* szName, int nMode = ios::out, int nProt = filebuf::openprot );
ofstream( filedesc fd );
ofstream( filedesc fd, char* pch, int nLength );
Parameters
szName
The name of the file to be opened during construction.
nMode
An integer that contains mode bits defined as ios enumerators that can be combined with the bitwise OR ( | ) operator. The nMode parameter must have one of the following values:
nProt
The file protection specification; defaults to the static integer filebuf::openprot that is equivalent to filebuf::sh_compat. The possible nProt values are:
To combine the filebuf::sh_read and filebuf::sh_write modes, use the logical OR ( || ) operator.
fd
A file descriptor as returned by a call to the run-time function _open or _sopen; filedesc is a typedef equivalent to int.
pch
Pointer to a previously allocated reserve area of length nLength. A NULL value (or nLength = 0) indicates that the stream will be unbuffered.
nLength
The length (in bytes) of the reserve area (0 = unbuffered).
Remarks
The four ofstream constructors are:
Constructor | Description |
ofstream() | Constructs an ofstream object without opening a file. |
ofstream( const char*, int, int ) | Contructs an ofstream object, opening the specified file. |
ofstream( filedesc ) | Constructs an ofstream object that is attached to an open file. |
ofstream( filedesc, char*, int ) | Constructs an ofstream object that is associated with a filebuf object. The filebuf object is attached to an open file and to a specified reserve area. |
All ofstream constructors construct a filebuf object. The first three use an internally allocated reserve area, but the fourth uses a user-allocated area. The user-allocated area is not automatically released during destruction.