Tcl Script File (.tcl) Definition
An ASCII text file (with the extension .tcl) that contains importable Tcl code or an executable Tcl script.
Tcl, an abbreviation of the name "Tool Command Language", is a scripting language for controlling and extending software applications. A .tcl file contains a Tcl script, which is composed of Tcl functions and can also include Quartus® Prime Application Programming Interface (API) functions used as commands.
You can run Tcl scripts at a command line, in the Quartus® Prime Tcl Console window, with the Tcl Scripts command on the Tools menu, or as tasks in the Tasks window.