int Ns_TclGetOpenFd ( Tcl_Interp* , char* chanId, int write, int* fdPtr );
This function returns an open Unix file descriptor for the specified channel. The value at fdPtr
is updated with a valid Unix file descriptor.
The write
parameter specifies if a writable (TRUE) or readable (FALSE) channel is being requested. See the Tcl 7.6 documentation for Tcl_GetChannelFile.
This function returns TCL_ERROR or TCL_OK.