sockets

hi,
I have a question about C sockets. Is this possible:
1. start application, and establish socket connection.
2. quit application, without closing connections (!!)
3. restart application, and continue using old connections?

Andreas R.

"Andreas Røsdal" <andrearo@stud.ntnu.no> skrev i en meddelelse
news:Pine.LNX.4.58.0401301359530.17224@tiger.stud. ntnu.no...
> hi,
> I have a question about C sockets. Is this possible:
> 1. start application, and establish socket connection.
> 2. quit application, without closing connections (!!)
> 3. restart application, and continue using old connections?
>
> Andreas R.

Short, No you can't.
As you quit your application, you close all open File descriptores.
And when you create your socket it will be assigned a file descriptor.
which it basically uses for I/O functions at low level.

R.Kj.

On Fri, 30 Jan 2004 14:00:11 +0100, Andreas Røsdal wrote:

> hi,
> I have a question about C sockets. Is this possible:
> 1. start application, and establish socket connection.
> 2. quit application, without closing connections (!!)
> 3. restart application, and continue using old connections?
>
> Andreas R.

Not as described. You might consider having the initial startup spawn a
second process that will persist (see fork(2), various others) to maintain
the connections, that your application connects and disconnects from.

--
Some say the Wired doesn't have political borders like the real world,
but there are far too many nonsense-spouting anarchists or idiots who
think that pranks are a revolution.

Andreas Røsdal wrote:

> hi,
> I have a question about C sockets. Is this possible:
> 1. start application, and establish socket connection.
> 2. quit application, without closing connections (!!)
> 3. restart application, and continue using old connections?

It depends on what you mean by 'connection'. If you mean a TCP connection then
the answer is no. If you mean some sort of UDP connection, then the answer is
maybe, if the application's UDP connection protocol allows it.

> Andreas R.

--
Phil Frisbie, Jr.
Hawk Software
http://www.hawksoft.com

"René Kjellerup" <webmaster@keenan.dk> wrote in message
news:bvdlt1$2n3o$1@news.f.de.plusline.net...
>
> "Andreas Røsdal" <andrearo@stud.ntnu.no> skrev i en meddelelse
> news:Pine.LNX.4.58.0401301359530.17224@tiger.stud. ntnu.no...
> > hi,
> > I have a question about C sockets. Is this possible:
> > 1. start application, and establish socket connection.
> > 2. quit application, without closing connections (!!)
> > 3. restart application, and continue using old connections?
> >
> > Andreas R.
>
> Short, No you can't.
> As you quit your application, you close all open File descriptores.
> And when you create your socket it will be assigned a file descriptor.
> which it basically uses for I/O functions at low level.
>

What you describe sounds a great deal like the way "screen" functions. You
might hunt down the source for screen and see what they're doing.

JW

Jacob Westenbach wrote:
> "René Kjellerup" <webmaster@keenan.dk> wrote in message
> news:bvdlt1$2n3o$1@news.f.de.plusline.net...
>
>>"Andreas Røsdal" <andrearo@stud.ntnu.no> skrev i en meddelelse
>>news:Pine.LNX.4.58.0401301359530.17224@tiger.stu d.ntnu.no...
>>
>>>hi,
>>> I have a question about C sockets. Is this possible:
>>> 1. start application, and establish socket connection.
>>> 2. quit application, without closing connections (!!)
>>> 3. restart application, and continue using old connections?
>>>
>>>Andreas R.
>>
>>Short, No you can't.
>>As you quit your application, you close all open File descriptores.
>>And when you create your socket it will be assigned a file descriptor.
>>which it basically uses for I/O functions at low level.
>>
>
>
> What you describe sounds a great deal like the way "screen" functions. You
> might hunt down the source for screen and see what they're doing.
>
> JW
>
>

well the screen is also treated as a file, with FD 0, 1, and 2 which is
in, out, and err respectivly, as are sockets.
That is if you use BSD Sockets, though I don't know for sure in any
other cases.

R.Kj.
--As life grows older, I gain experience.