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Re: Somewhat off-topic, but hard to find better portability people.
From: |
Ralf Wildenhues |
Subject: |
Re: Somewhat off-topic, but hard to find better portability people. |
Date: |
Wed, 17 Sep 2008 08:59:05 +0200 |
User-agent: |
Mutt/1.5.18 (2008-05-17) |
Hello Peter,
* Peter Seebach wrote on Wed, Sep 17, 2008 at 06:12:40AM CEST:
>
> I am looking for systems on which the following *do not* work:
>
> unset
Quoting the Autoconf manual:
| `unset'
| In some nonconforming shells (e.g., Bash 2.05a), `unset FOO' fails
| when `FOO' is not set. Also, Bash 2.01 mishandles `unset MAIL' in
| some cases and dumps core.
So look for systems with those bash versions.
> "$@" (expanding to null, not an empty string, when no positional parameters)
systems are listed for this, too:
| `$@'
| One of the most famous shell-portability issues is related to
| `"$@"'. When there are no positional arguments, Posix says that
| `"$@"' is supposed to be equivalent to nothing, but the original
| Unix version 7 Bourne shell treated it as equivalent to `""'
| instead, and this behavior survives in later implementations like
| Digital Unix 5.0.
> (As is so often the case, "portable" is not exactly a boolean; what I want to
> be able to do is tell people not just that there exists a machine where
> one of these doesn't work, but what it might be, so they can make informed
> decisions about it.)
Sure. If you're missing systems mentioned in the Autoconf manual,
then they should be added. Typically, if we find a newer system
that still exposes an old bug, we list it.
Cheers,
Ralf
Re: Somewhat off-topic, but hard to find better portability people., James Youngman, 2008/09/18