Ah, great! Also the separation you mentioned is nice, that the REPL indeed is intended to operate in a separate "controlling channel". It's interesting that different platforms even have IO API:s for that, I had no idea. So for what I was looking for, that I missed was this section in the manual, was: - The REPL interaction channel will be standard input and standard output. And the way to figure out how to use it is.. gsc [-:runtimeoption,…] And "-" is a "debugging" option, documented by The ‘d’ option sets various debugging options. The letter ‘d’ is followed by a sequence of letters indicating suboptions. so hence "-:d-", so: $ *echo '(display "Hello world\n"),q' | gsc -:d-* Gambit v4.8.0
Hello world
$ Great! Totally unimportantly, could I enable REPL echoing of the input commands, or turn off REPL output altogether, from the command line? So $ *echo '(display "Hello world\n"),q' | gsc -:d- [somemorearg]* Gambit v4.8.0
(display "Hello world\n") Hello world
,q
$ and $ *echo '(display "Hello world\n"),q' | gsc -:d- - [somemorearg]* Hello world $