The document is archived and information here might be outdated
Visual Studio .NET 2003
The integer expression formed from one or more of these constants determines the type of reading or writing operations permitted. It is formed by combining one or more constants with a translation-mode constant.
The file constants are as follows:
- Repositions the file pointer to the end of the file before every write operation.
- Creates and opens a new file for writing; this has no effect if the file specified by filename exists.
- Returns an error value if the file specified by filename exists. Only applies when used with _O_CREAT.
- Opens file for reading only; if this flag is given, neither _O_RDWR nor _O_WRONLY can be given.
- Opens file for both reading and writing; if this flag is given, neither _O_RDONLY nor _O_WRONLY can be given.
- Opens and truncates an existing file to zero length; the file must have write permission. The contents of the file are destroyed. If this flag is given, you cannot specify _O_RDONLY.
- Opens file for writing only; if this flag is given, neither _O_RDONLY nor _O_RDWR can be given.