TCL had an amazing architecture for someone who was working in C. In C, you'd (1) create an instance of a TCL interpreter, (2) register your C functions with the TCL interpreter, and then (3) load scripts into the TCL interpreter. You'd do all your fast stuff in your C code, and just use the TCL for stitching together the high-level logic.

This, it is really easy to embed the tcl interpreter. Far easier than perl and python, even easier than lua.

Especially the commands were invoked command_name(argv, argc) and the thing was just like a CS 101 C program. Dead simple, and as they mentioned just used to orchestrate the fast stuff. You shouldn't make a command block a long time, but you could grab a handle to the output destination and set it up to stream output there from the C.