Subject: Re: cat(1) question: multiple "-"s
To: Johnny Billquist <firstname.lastname@example.org>
From: Steven M. Bellovin <email@example.com>
Date: 04/18/2006 13:36:40
On Tue, 18 Apr 2006 19:31:13 +0200, Johnny Billquist <firstname.lastname@example.org>
> Doh! And as others have already noted later, zsh don't do anything like
> this. It just concatenates the files, and feed the result to stdin.
> Hmm, I wonder if it wouldn't be possible to simulate eofs on a stream,
> but then present more data. I believe that is what really would be
> Thinking of it, I don't think that it's possible. The only stream that I
> know, that can do this, are ttys. Anyone?
If we had streams, and if pipes were streams, it could be done quite
easily -- make sure there's a 0-length record present. Otherwise, it's
not particularly easy. It would take a kernel multiplexor that you handed
several files -- more likely, several file descriptors -- that would read
the first until it ended, give EOF, then the next, etc.
--Steven M. Bellovin, http://www.cs.columbia.edu/~smb