Where do Tcl shell commands go in command-line mode?

[Zhihui-SJTU]

In OpenROAD's ​​GUI mode​​, commands entered in the Tcl shell are ultimately processed by TclCmdInputWidget, where the user's input is stored in the variable command(as shown in the screenshot).
​​Question:​​ For OpenROAD's ​​command-line mode​​, which variable stores the user's input commands in the Tcl shell?

[maliberty]

I believe tcl readline manages the history itself. I don't think there is any code in OR to handle the history in non-gui mode.

[Zhihui-SJTU]

tcl readline is optional. What if tcl readline is not enabled?

[maliberty]

Then there is no history recall

[Zhihui-SJTU]

In command-line mode, Tcl_Eval(interp, command) is not called to handle user input commands. If the input is handled by the tcl library itself, will it?

[maliberty]

I don't understand "will it". The tcl interpreter gets inputs and dispatches it. There is no need for TclEval.