Ascii Menu I/O redirection

[Steven D'Aprano]

On Sat, 20 Sep 2008 23:14:26 +0200, Hendrik van Rooyen wrote:

> class console(object):
>     """
>     This spoofs a single file like object, using stdout & - in
>     (Minimalistic proof of concept implementation) """
> 
>     def __init__(self):
>         self.read = sys.stdin.read
>         self.readline = sys.stdin.readline
>         self.write = sys.stdout.write
>         self.flush = sys.stdout.flush
>         self.closeout = sys.stdout.close # keep references to close
>         self.closein = sys.stdin.close
> 
>     def close(self):
>         self.closein()
>         self.closeout()


I'm not sure that closing stdin and stout are a good idea. This could 
have side-effects for other parts of your program, and will almost 
certainly end badly if you're running in the interactive interpreter.

Other than that, what you've done seems reasonable, although since every 
instance of console() has the same state, I'd write it slightly 
differently:

class console(object):
    """
    This spoofs a single file like object, using stdout & - in
    (Minimalistic proof of concept implementation) 
    """
    read = sys.stdin.read
    readline = sys.stdin.readline
    write = sys.stdout.write
    flush = sys.stdout.flush
    closeout = sys.stdout.close
    closein = sys.stdin.close
    @classmethod
    def close(cls):
        cls.closein()
        cls.closeout()



[...]

> Questions are:
> 
>     Is this a reasonable way of doing this kind of thing? Is there a
>     canonical or better way of doing it? Am I missing something?

It seems to me that you might have been better off to write your program 
to take two files, an input and an output, instead of forcing both to go 
to the same file.

if 'serial' in sys.argv:         # for RS-232 i/o to terminal
        infile = open('/dev/ttyS0','r+b')
        outfile = infile
    else:                                 # console i/o
        infile = sys.stdin
        outfile = sys.stdout



Hope this helps.


-- 
Steven