Re: Ada.Command_Line and wildcards

["Hyman Rosen" <hyman.rosen@gmail.com>]

On Mar 6, 7:56 am, Georg Bauhaus <bauh...@futureapps.de> wrote:
> When it comes to echo *.ads, a decision was necessary as to what
> should happen when there is no matching file name. The choice was
> not: reflect this fact and produce the empty result. This might
> have had other consequences somewhere else. Instead, it
> was to produce the pattern itself--which is very different from
> a file name.

One of those other consequences is that many, if not most, UNIX
programs treat a no-argument command as meaning "do your default
action". So 'ls' with no directory arguments lists the current
directory and 'cat' with no file arguments reads standard input, and
so forth. If I wrote 'cat *.ads' and there were no such files and the
shell expanded that to nothing, 'cat' would sit endlessly awaiting
input from the terminal. As it stands, I get 'cat: cannot open *.ads'
and I see the problem. What we have is a design that works pretty well
interactively and pretty well in scripts, failing only on a few weird
cases. That's good enough, because it gets you to 90% of what you
need, and Worse is Better.