system call: how to get access to results ?

[David Pirotte]

Hello,

I have defined the following very simple function, to get access
to the system date:

        (define (system-date . rest)
          (if (null? rest)
              (system "date '+%d-%m-%Y'")
              (system (format #f "date ~A" (car rest)))))

However, I don't know how I can get access to the result, when sending
a date string and expecting a result, such as:

        (system-date (format #f "--date='~A' '+%w'" "09/15/2000")
        5
        0

The system "displays" the result, but returned value is the exit code

How can I "get access" to the expected returned value ?

thanks,
david