Fw: poor man's wget

Fw: poor man's wget

[Andrej Borsenkow]

I found it on c.u.s

Amusing is it :-)

-andrej

"brian hiles" <bsh@rainey.blueneptune.com> wrote in message
news:<sj2npdk15pj111@corp.supernews.com>...
> Martin Ramsch <m.ramsch@computer.org> wrote:
> > I only now discovered the special handling of redirections to
> > /dev/tcp/host/port introduced with Bash 2.x, and I like this small
> > contruct which requests the main page from a web server:
> >   { echo "GET /" >&0; cat; } <>/dev/tcp/www.server.com/80
> > Also the first time a "<>" redirection is useful for me ... ;-)
>
> The /dev/{tcp,udp} special notation is a reflection of the same
> feature introduced in ksh93 (at least I think I'm getting the
> relationship correct!) BTW, "<>" is an undocumented feature of
> plain ol'd bourne shell since, well, _forever_.
>
> Jeffery Korn (yes, son of _that_ guy) posted a similar solution two
> years of so back to this newsgroup.
>
> Apparently, however, bash 2.x does ksh93 one better by not requiring
> the <hostname> address to be resolved to an IP address. Kudoes to
> the bash development team :)
>
> Incidentally, I would rephrase the above as:
>
> { echo GET /; echo; cat; } <>/dev/tcp/www.server.com/80
>
> Isn't the additional newline necessary? (Not tested.)
>
> It's quite amusing to determine the time from a daytime server:
>
> read -r </dev/udp/0.0.0.0/13; print -r -- "$REPLY"
>
> -Brian

Re: Fw: poor man's wget

[Peter Stephenson]

> > { echo GET /; echo; cat; } <>/dev/tcp/www.server.com/80

This could be done without much difficulty by simplifying zftp_open and
wiring the code into the existing redirection stuff.  Unfortunately no-one
else apart from Zefram has shown much interest in the network stuff, so
it's unlikely to happen any time soon.

You could probably then rewrite most if not all of zftp as shell functions.

-- 
Peter Stephenson <pws@cambridgesiliconradio.com>
Cambridge Silicon Radio, Unit 300, Science Park, Milton Road,
Cambridge, CB4 0XL, UK                          Tel: +44 (0)1223 392070

Re: Fw: poor man's wget

[Zefram]

Peter Stephenson wrote:
>> > { echo GET /; echo; cat; } <>/dev/tcp/www.server.com/80

Having the shell give pathnames magic semantics that the rest of the
OS doesn't is evil and rude.  That sort of feature should be done in a
user-space filesystem.

>This could be done without much difficulty by simplifying zftp_open and
>wiring the code into the existing redirection stuff.  Unfortunately no-one
>else apart from Zefram has shown much interest in the network stuff, so
>it's unlikely to happen any time soon.

Hmm.  I do have some future plans for a shell module that would do
generic socket stuff of this nature (using a more rational syntax),
though, as you say, it's unlikely to happen any time soon.

>You could probably then rewrite most if not all of zftp as shell functions.

Yes.

-zefram