shell:exec-with-io-redirect
builtin-function
(shell:exec-with-io-redirect input prog &rest args)
Executes the program prog with arguments args. The string input is
used as standard input. Returns the standard output as a string.
make-html > (shell:exec-with-io-redirect null "uname" "-a")
it: "Linux pc 4.19.0-8-amd64 #1 SMP Debian 4.19.98-1 (2020-01-26) x86_64 GNU/Linux\n"