/usr/bin/plt-r6rs is in racket 5.1.3+dfsg1-1.
This file is owned by root:root, with mode 0o755.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 | #!/bin/sh
# This script was created by make-mzscheme-launcher
# {{{ bindir
bindir="/usr/bin"
# }}} bindir
exec "${bindir}/racket" -N "$0" '-I' 'scheme/init' '-l-' 'r6rs/run.rkt' ${1+"$@"}
|