status.i4.v = window_to_text_file_c(file_name.i1a.r, window_id.i2.v,
					    num_rows.i4.v, top_row.i4.v,
					    match_data.s.r, options.u4.v

	This routine allows the caller to copy the contents of a TV window
	to a text file.

	file_name	null terminated destination file name
	window_id	ID of desired window
			(WMNGR_BACKGROUND -> background window,
			 WMNGR_WHOLE_DISPLAY -> entire visible display,
			 WMNGR_ERROR_WINDOW -> error display window,
			 otherwise -> ID of desired window)
	num_rows	number of rows of text to display  (Note: If a value
			of zero is passed for this parameter, the visible
			window will be displayed.  Otherwise, "num_rows" of
			the scroll buffer will be displayed.  If this value
			is negative, both the visible window and the scroll
			buffer will be displayed.)
	top_row		top row to display (Note: This value is only used
			when displaying scroll buffer text.) (must be >= 1)
	match_data	text matching information which determines which lines
			will be copied (If a value of NULL is passed for
			this argument, all requested lines will be copied.)
			(structure of type STR_SEARCH_INFO)
	options		copy options (not used)
	[callback_func]	address of user supplied function to modify each
			line of the output to be called as follows:
			copy_line.i4.v = callback(output_line.i1a.r,
			(default is NULL)
	[callback_data]	pointer to user-supplied data to be passed to the
			callback function
			(default is NULL)
	[args]		additional arguments (not used)
			(default is NULL)

	This function returns ACNET status values as follows:

	OK			success
	CBS_INVARG		invalid window ID or top row was specified
	CBS_NO_WINDOW		window doesn't exist
	CBS_NOTOPN		couldn't open the output file
	CBS_GENERR		file write failed

	This function requires the following include files:

	cnsparam_h, cbslib_h, acnet_errors_h

	Related functions:

	window_to_excel_file_c, window_to_paste_buffer_c,
	window_to_printer_c, window_to_graphic_screen_c,

	C/C++ usage:

	static const char	file_name[] = "/my_path/my_file.txt";
	short	window_id;
	int	status;
	int	num_rows = 0;
	int	top_row = 1;
	unsigned int	options = 0;
	int	callback_func(char *output_line, void *callback_data,
			      int line_number);
	void	*calllback_data = (void *) NULL;
	void	*args = (void *) NULL;

	status = window_to_text_file_c(file_name,window_id,num_rows,top_row,