DosDupHandle
Bindings: C, MASM
This call returns a new file handle for an open file, which refers to the
same position in the file as the old file handle.
DosDupHandle (OldFileHandle, NewFileHandle)
OldFileHandle (HFILE) - input
Current file handle.
NewFileHandle (PHFILE) - input/output
Address of a Word. On input, values and their meanings are:
Value Definition
FFFFH Allocate a new file handle and return it here.
<>FFFFH Assign this value as the new file handle. A valid value is
any of the handles assigned to standard I/O, or the handle
of a file currently opened by the process.
On output, a value of FFFFH returns a value for
NewFileHandle, allocated by OS/2.
rc (USHORT) - return
Return code descriptions are:
0 NO_ERROR
4 ERROR_TOO_MANY_OPEN_FILES
6 ERROR_INVALID_HANDLE
114 ERROR_INVALID_TARGET_HANDLE
Remarks
Duplicating the handle duplicates and ties all handle-specific
information between OldFileHandle and NewFileHandle. For example, if you
move the read/write pointer of either handle by a DosRead, DosWrite, or
DosChgFilePtr function call, the pointer for the other handle is also
changed.
The valid values for NewFileHandle include the following handles for
standard I/O, which are always available to the process:
0000H Standard input
0001H Standard output
0002H Standard error.
If a file handle value of a currently open file is specified in
NewFileHandle, the file handle is closed before it is redefined as the
duplicate of OldFileHandle. Avoid using arbitrary values for
NewFileHandle.
Issuing a DosClose against a file handle does not affect the duplicate
handle.
Created using Inf-PHP v.2 (c) 2003 Yuri Prokushev
Created using Inf-HTML v.0.9b (c) 1995 Peter Childs