[bug?] Invalid file descriptor ignored

[bug?] Invalid file descriptor ignored

[Martijn Dekker]

There is some strange and inconsistent behaviour when trying to write to
a non-open file descriptor. I think the following three test cases
should at least return a non-zero status, but only the third one does:

% echo hi 1>&-; echo $?
0
% { echo hi; } 1>&-; echo $?
zsh: write error: bad file descriptor
0
% echo hi 2>&- 1>&2; echo $?
zsh: 2: bad file descriptor
1

Other shells behaviour, FWIW: All other shells return a non-zero status
for all three cases. (d)ash, bash, yash produce an error message for the
first two cases but not the third. ksh88, ksh93 and {pd,m}ksh are silent
on all three.

Thanks,

- M.

Re: [bug?] Invalid file descriptor ignored

[Peter Stephenson]

On Mon, 29 Feb 2016 07:44:52 +0100
Martijn Dekker <martijn@inlv.org> wrote:
> There is some strange and inconsistent behaviour when trying to write to
> a non-open file descriptor.

Yes, I noticed not so long ago that some cases got changed so any error
was deliberately ignored.  Bart pointed out an ancient message on the
mailing list about this.  I can't remember what that discussion was
about now, though...  it doesn't appear to be the discussion about
management of fdtable from mid October.

pws

Re: [bug?] Invalid file descriptor ignored

[Bart Schaefer]

On Feb 29,  9:39am, Peter Stephenson wrote:
} Subject: Re: [bug?] Invalid file descriptor ignored
}
} On Mon, 29 Feb 2016 07:44:52 +0100
} Martijn Dekker <martijn@inlv.org> wrote:
} > There is some strange and inconsistent behaviour when trying to write to
} > a non-open file descriptor.
} 
} Yes, I noticed not so long ago that some cases got changed so any error
} was deliberately ignored.  Bart pointed out an ancient message on the
} mailing list about this.  I can't remember what that discussion was
} about now, though...

Most recently it was in the [refactor memstream for "print -v"] thread at
the beginning of January.