On Fri, Sep 27, 2013 at 12:11 AM, Grant Edwards <invalid@invalid.invalid> wrote: > On a Unix system when you invoke a program, you "pass" it four things: > > 1) A dictionary where keys/values are both strings [enviornment variables] > 2) A list of strings [command line args] > 3) A set of open file descriptors. > 4) The current working directory. > > You can provide input values to the program through any of these. > > For interactive programs, 2 and 3 are the most convenient.
Hrm, not sure about #3 for interactive programs, unless you specifically mean the three standard streams. With most Unix shells, you should be able to set environment variables: PGUSER=fred PGPASSWORD=secret psql Not as convenient as #2, but far easier than passing an open file descriptor. Of course, passing file descriptors around is pretty easy programmatically, but when you say "interactive" I assume you're talking also about an interactive shell. GUI interactions of course follow their own rules completely. In most systems, it's really easy to invoke an application with one argument, a file name; it's generally much harder to customize the arguments at the keyboard. OS/2 had a facility for doing that. You just put square brackets into the configured args and it'd turn it into a prompt: --foo=bar --mode=[Choose mode, 1-3:] %* You'd get a nice little popup with the prompt you specified, and whatever you type gets put into the args. Haven't seen that in any other system - at least, not as conveniently. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
