From: "Josh M. Osborne" <stripes@va.pubnix.com>
Date: Mon, 28 Aug 95 14:07:52 PDT
To: Piete Brooks <Piete.Brooks@cl.cam.ac.uk>
Subject: Re: SSL trouble
In-Reply-To: <"swan.cl.cam.:216660:950828181616"@cl.cam.ac.uk>
Message-ID: <RAA13233.199508282105@garotte.va.pubnix.com>
MIME-Version: 1.0
Content-Type: text/plain


In message <"swan.cl.cam.:216660:950828181616"@cl.cam.ac.uk>, Piete Brooks writ
[...]
>PS1: PERL gurus: Anyone know how to test whether there is input waiting on a
>     file handle ? I know about seeing if there is data waiting for the next
>     sysread type read, but not on the next <SERVE> type read. Ideas ?

I don't think there is one.  I would just use select() on FD, and then
a subrutine much like this:

sub syswrite {
    local($FH, $buf) = @_;

    local($len, $offset, $wlen) = (length($buf), 0, 0);

    while($len) {
        $wlen = syswrite($FH, $buf, $len, $offset);
        die "Bad write $FH: $!" if (!defined($FH));

        $offset += $len;
        $len -= $wlen;
    }
}


Actually if you can use perl5 for the server (I assume this is the
server code you are worrying about) I have code that deals with
I/O from multiple sockets at once and drives an independant state
machine for each socket.

>PS2: PERL gurus: I fixed the SGI Challenge problem by HACKing it -- as I
>     thought it was a probleb with stdio in and out on the same socket.
>     The perl mand page warns:
>	If  your  stdio  requires an seek or eof between reads and
>	writes on  a  particular  stream,  so  does  perl.   (This
>	doesn't apply to sysread() and syswrite().)
>     so I change the one "print SERVE" line to a "syswrite(SERVE" and that
>     fixed it. However, does anyone know the "correct" way to use stdio for I/
>O?

For bi-directional pipes I tend to use sysread/syswrite anyway, but
you could just sprinkle "seek(SERVE, 0, 1)" liberally through the
code.

>PS3: I'd like to get the raw date in brloop (a sh script). In perl I'd just
>     use "time", and I can't see a way to get "date +" to yield the raw time.
>     I could use "date=`perl -e 'print time'`" but that seems OTT, and perl
>     may not be on teh users PATH. Any suggestions ?

"date '+%s'" does it under BSDI, but I'm not sure how portable it is.