_open_osfhandle

Article
12/18/2017

The latest version of this topic can be found at _open_osfhandle.

Associates a C run-time file descriptor with an existing operating-system file handle.

Syntax

  
      int _open_osfhandle (  
   intptr_t osfhandle,  
   int flags   
);

Parameters

osfhandle
Operating-system file handle.

flags
Types of operations allowed.

Return Value

If successful, _open_osfhandle returns a C run-time file descriptor. Otherwise, it returns –1.

Remarks

The _open_osfhandle function allocates a C run-time file descriptor and associates it with the operating-system file handle specified by osfhandle. The flags argument is an integer expression formed from one or more of the manifest constants defined in Fcntl.h. When two or more manifest constants are used to form the flags argument, the constants are combined with the bitwise-OR operator ( | ).

Fcntl.h defines the following manifest constants.

_O_APPEND
Positions a file pointer to the end of the file before every write operation.

_O_RDONLY
Opens the file for reading only.

_O_TEXT
Opens the file in text (translated) mode.

_O_WTEXT
Opens the file in Unicode (translated UTF-16) mode.

To close a file opened with _open_osfhandle, call _close. The underlying handle is also closed by a call to _close, so it is not necessary to call the Win32 function CloseHandle on the original handle.

Requirements

Routine	Required header
`_open_osfhandle`	<io.h>

For more compatibility information, see Compatibility in the Introduction.

Libraries

All versions of the C run-time libraries.

.NET Framework Equivalent

System::IO::FileStream::Handle

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