— Function: getenv name

Looks up name, a string, in the program environment. If name is found a string of its value is returned. Otherwise, #f is returned.

— Function: system command-string

Executes the command-string on the computer and returns the integer status code. This behaves the same as the POSIX system call.

— Function: program-arguments

Returns a list of strings, the first of which is the program name followed by the command-line arguments.