[avahi] What is the Format of data transmitted via Avahi - Is this possible

[Martin Nyolt]

Hello Rajesh,

This is probably not the right mailing list for your problem.

Avahi (Zeroconf) is just an advertisement of services on your network.
For instance with avahi you can advertise a printing service using the Internet Printing Protocol (IPP) over tcp at port 631.
In avahi, you would publish this example as type _ipp._tcp at port 631.

Avahi itself does not implement the actual service in any way. This is the responsibility of the service that told avahi to publish it (in this case this would be you).

So, yes: you would have to listen on the port you are advertising.
The choice of protocol depends on your application and clients, of course.
The kind of data you receive then depends on the service type you are advertising and the clients who assume they can speak to that service using the published protocol.
To support a wide range of clients, you will probably want to use an established protocol, such as IPP.

So you probably want to do some research on available printing protocols. I do not know them in detail.
This definitely goes beyond the scope of this list. Avahi is just concerned with the advertisement of that service, not with the actual service.

Best regards,
Martin

On 24/12/15 06:43, Rajesh Khan wrote:
> Hello all , I have been stuck on this issue for a while and wanted to know
> what my options are.
> I currently have an embedded device running embedded linux.
> Now I would like to advertise that device as a printer via Avahi (the
> device itself is not a printer). My current embedded linux flavour does not
> have CUPS installed in it and I would like to avoid it if possible.I
> recently found out that I could advertise my device using avahi-publish(1)
> <http://avahi.org/download/avahi-publish.1.xml>.  I have not tested this
> yet.Now suppose this works.
> My question is what kind of data will my device receive if a user selects
> this newly advertised printer and issues a print command  from a text
> editor (say using textmate).I would like to manipulate that data on my
> device.Will my device need to be listening on a certain socket/port ? How
> will I receive that data ? What will be the format of that data ? Any
> suggestions or hints on this would be more than appreciated.
>
>