_dup

Duplicates a file handle.

int _dup (int handle);

int dup (int handle);

Required Header
<io.h>

Return Value

Each of these functions returns a new handle to the currently open file. -1 indicates an error.

Parameters

handle

  A handle to an open file

Remarks

The _dup function creates a new handle to the currently open file handle handle. Both the new handle and the old handle refer to the same file. Use _fileno to obtain the handle of a stream.

_dup is mostly used to duplicate the predefined handles for stdin, stdout and stderr before they are reassigned to other files.

Low Level I/O

See Also    _close, _dup2, _open