int Ns_TclGetOpenChannel ( Tcl_Interp* , char* chanId, int write, int check, Tcl_Channel* channPtr );
This function fills in channptr
with a channel open in the passed-in interpreter if one exists. It returns TCL_OK or TCL_ERROR. The chanId
is a channel name (the handle that Tcl uses).
This function also has the ability to check if a channel is opened for reading or writing. If check
is true, the check is performed. If write
is true, the channel is checked for writeability. If write
is false, the channel is checked for readability. If the check is performed and fails, then an error is returned and appended to the interpreter.