\section{Scope Commands} \label{Scope Commands} The {\tt W} command (scope {\em WATCH}) is present in most implementations of TECO. There are two different variations of the {\tt W} command. Neither, one, or both may be present. {\tt ET} flag Bits 9 and 10 indicate which variation(s) are configured and can be used. \subsection{Video Terminal Scope Commands} \label{Video Terminal Scope Commands} If the VT support is present and your terminal is a video terminal (such as a VT05, VT52, or VT100), {\tt ET} flag Bit 9 (value 512) will be on. \begin{table}[h] \caption{Video Terminal Watch Commands} \end{table} \nopagebreak \begin{list}{}{\labelsep 20pt} \item[{\em COMMAND}] {\em FUNCTION} \item[{\tt -1W}] Refresh the terminal's screen to show the contents of the text buffer. \item[{\tt -nW}] Tell the video terminal screen refresher that the top {\tt n}-1 lines of the screen have been altered. The screen refresher will completely redraw the top {\tt n}-1 lines of the screen upon the next {\tt -1W} command. \item[{\tt nW}] Place the default cursor line at line {\tt n} of the screen. The initial default cursor line is line 16. This command makes the window support forget the screen image and any special associated modes ({\tt SEEALL}, {\tt MARK}, {\tt HOLD}). \item[{\tt 0W}] Equivalent to {\tt 16W}. \item[{\tt W}] Forget screen image and special scope modes. \iftecoelevenonly \item[{\tt -1000W}] Forget that output was done. Normally, if the user outputs to the terminal with a command such as {\tt T}, {\tt n}\caret{\tt T}, or \caret{\tt A}, TECO will believe that the window needs updating, and upon the next {\tt -1W} command, TECO will refresh the entire window display. Issuing the {\tt -1000W} command informs TECO that the output command did not destroy the window. {\em [TECO-11 only]} \fi The {\tt :W} commands are used to interrogate and set (see {\tt m,n:W} below) video terminal status information, as well as implement some of the more advanced features of the video terminal {\em WATCH} functions. \end{list} \begin{table}[h] \label{Video Terminal Status Commands} \caption{\bf{Video Terminal Status Commands}} \end{table} \nopagebreak \begin{list}{}{\labelsep 20pt} \item[{\em COMMAND}] {\em FUNCTION} \item[{\tt 0:W}] Return a number representing the type of scope in use as the editing terminal. Current values are: \begin{list}{}{\labelsep 10pt} \item[{\tt 0}] VT52 \iftecotenonly \item[{\tt 1}] VT61 [TECO-10 only] \fi \item[{\tt 2}] VT100 in VT52 mode \item[{\tt 4}] VT100 in ANSI mode \item[{\tt 6}] VT05 \item[{\tt 8}] VT102 in ANSI mode \item[{\tt 10}] VK100 (GIGI) \end{list} \item[{\tt :W}] Equivalent to {\tt 0:W} \item[{\tt 1:W}] Return or set the horizontal size of the user's editing scope. This number represents the number of character positions available horizontally along the face of the scope. If this value is changed (see {\tt m,n:W} below), the operating system is automatically informed of the terminal's new width setting, and the appropriate control sequence is issued to physically change the terminal's screen mode (80 versus 132 column mode) if needed. \item[{\tt 2:W}] Return or set the vertical size of the user's editing scope. This number represents the number of lines of text that can appear on the screen of the terminal. This number is affected by use of the {\tt m,7:W} command (set scrolling region). \item[{\tt 3:W}] Return or set SEEALL mode. 0 represents off and -1 represents on. In SEEALL mode, a visible indication is shown in the window for every character, including characters that normally don't print. \item[{\tt 4:W}] Return or set ``mark'' status of window support. 0 means that no mark has been set. A value of {\tt n} means that a mark has been set at buffer {\em dot} position {\tt n}-1. This status is used by software that uses the window support and by the support itself in the case of scopes that support reverse video. \item[{\tt 5:W}] Return or set the hold mode indicator. 0 means off, -1 means hold whole screen, and a positive value, {\tt n}, means hold all but top and bottom {\tt n} lines. If hold mode is on, then scrolling is inhibited until the cursor is about to run off either end of the screen. This makes the window display more palatable on terminals on a slow line. If hold mode is on, the window support will scroll the window as necessary in an attempt to keep the cursor centered. \item[{\tt 6:W}] Returns buffer pointer position of character that was in the upper left hand corner of the window as of the last {\tt -1W }command. \item[{\tt 7:W}] Return or set the number of lines in the scrolling (command dialogue) portion of the screen. If {\tt n} is zero, then split screen scrolling is disabled. When split screen scrolling is enabled, {\tt n} lines (as specified) are reserved at the bottom of the screen to scroll the terminal interaction. The remainder of the screen is used as a display window into the text buffer, and is automatically updated by TECO immediately before each command prompt. This feature functions only on terminals capable of split screen scrolling, such as members of the VT100 and VT200 families. The value of {\tt n} must be greater than 1, and scope height minus {\tt n} must be greater than 9. Whenever the scrolling region's size is modified (that is, whenever an {\tt m,7:W} command is executed), TECO alters the scope's height ({\tt 2:W}) accordingly. For example, if {\tt 2:W} is currently returning a value of 24, then after a {\tt 5,7:W} command {\tt 2:W} will return a value of 19. Executing a {\tt 0,7:W} will restore {\tt 2:W} to 24. \item[{\tt m,n:W}] Sets the entity represented by {\tt n:W} to {\tt m} and returns a value. If the new setting has been accepted, the returned value is {\tt m}. Elsewise, the returned value is either the old value associated with {\tt n:W} or whatever new setting was actually set. In all cases, the returned value reflects the new current setting. Specific operating systems may put restrictions on the valid values for {\tt m}. Note that each {\tt m,n:W} command returns a value, even if your only intent is to set something. Good programming practice suggests following any command which returns a value with {\tt } or \caret{\tt [} if you don't intend that value to be passed to the following command. \end{list} \subsection{Refresh Scope Commands} \label{Refresh Scope Commands} If refresh scope support is present and a refresh scope is available (such as a VS60 or a VR12), bit value 1024 of the ET flag will be on. \begin{table}[h] \caption{\bf{Refresh Scope Watch Commands}} \label{Refresh Scope Watch Commands} \end{table} \nopagebreak \begin{list}{}{\labelsep 20pt} \item[{\em COMMAND}] {\em FUNCTION} \item[{\tt W}] Update the refresh scope screen to reflect the contents of the text buffer surrounding the text pointer ({\em dot}). \item[{\tt 0W}] Turn off the refresh scope display. \item[{\tt nW}] Set the number of lines to be displayed around the text pointer to {\tt n}. \end{list}