OpenEuphoria

Re: system() function

• Posted by Robert Craig <rds at ATTCANADA.NET> Dec 17, 1999
• 495 views

Brian Broker writes:
> I know this has been brought up before but couldn't find
> a solution.  I'd like to capture output of a DOS program
> without sending the output to a file.
> Is there a way to do this?  (a library with a system() function
> that captures the output and lets you assign it to a
> sequence variable)
> Are there plans on adding this functionality to the next
> release of Euphoria?

As you are probably aware, you can already say things like:
       system("myprog > myoutput", 2)
to get the output of "myprog" into a file called "myoutput".
I guess what you want is to get the output back as a sequence
of characters, or sequence of lines of characters, without
ever creating a temporary file.

I don't know of anything special that I can do in the interpreter
to capture the output without creating a file. I don't plan to add
a library routine for this, but here's something I just wrote.
It uses a temporary file. I tested it lightly.

function command_output(sequence command)
-- return the output of a command
-- as a sequence of characters
    integer fn, c
    sequence result

    system(command & " > cmdtemp.dat", 2)
    result = ""
    fn = open("cmdtemp.dat", "r")
    if fn = -1 then
        return result
    end if
    while 1 do
        c = getc(fn)
        if c = -1 then
            exit
        end if
        result = append(result, c)
    end while
    close(fn)
    system("del cmdtemp.dat", 2)
    return result
end function

-- TEST
sequence r

r = command_output("dir *.ex")
puts(1, r)


Regards,
   Rob Craig
   Rapid Deployment Software
   http://www.RapidEuphoria.com