# TCL overview

Terminal Control Language (TCL) is the gateway to all D3
functionality. TCL is a system-level command language with system-defined
or user-defined statements that can be executed individually or sequentially.
System-defined statements are called TCL commands. User-defined statements
are: macros, menus, and cataloged FlashBASIC programs.

The first word of a TCL statement must be either a system
command, macro, menu, or cataloged BASIC program.

The : is the TCL prompt. TCL commands can be typed when the
TCL prompt displays. The completed command is entered for processing
by pressing CTRL+M or Enter. Because mistakes do occur, TCL editor
and TCL stack facilities are provided.

The TCL editor allows
corrections to commands after they are entered, but before they are
executed. The TCL stack editor stacks each command entered at the
TCL prompt and allows you to recall commands for correction and/or
execution.

TCL commands include the Access Query Language (AQL)
and spooler commands. AQL is a system-level information retrieval
language that allows you to query your database without writing complex
programs. The spooler commands allow you to control how information
is output to the printer.

## Example(s)

```
who
create-file test.file 3 7
copy md * (t
compile bp *
sort entity by name name
```

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Source: https://d3codex.com/tcl/tcl-overview/ - part of the D3Codex reference.