Check for internet

Is there a good/preferred way to check for internet connection?

Everything I have tried, if there isn't a connection, will "lock" the system for 30 seconds while checking for NIC card and such. Not good.

@mritter0

Hmm...

The old way was to open bsdsocket.library. If it failed, there was no TCP/IP stack running.

You can't do that on OS4, but when you call connect() it should return an error straight away.

I've never noticed anything freezing, however the program you are running may pause waiting for a timeout.

@mritter0
You could try entering C:GetNetStatus in a shell.

@mritter0

Well the network is up all the time in loopback mode (at least notmally, I don't if there is way to prevent that).

You might be able to query the routing lists via GetRouteInfo() to find out if the machine is on the LAN, (or perhaps some other API function I missed) , Ranger can show the configured interface so that may be possible, but I don't think you can work out if the router is then connected to the internet without at least pinging a remote address.

Can't you use shownetstatus? it'll tell you what the default gateway address is. If it's 0.0.0.0 then there is probsbly no internet.

In my S:Network-Status, after the AddNetInterface line, I have the following:
It's probably not fully failsafe, but it usually does the trick for me.

Play around with the lengths of the Wait commands if needed.

Best regards,

Niels

Thanks for the script ideas. But this is in the development forum. Looking for C code.

@mritter0
Everything you need to know is in the bsdsocket.library autodoc

Some suggestions for reading.

ObtainInterfaceList()

If no interfaces have been added you can't be online, and vice verca.

If you need more info perhaps look at

QueryInterfaceTagList()

Can't give you code examples as I've never done it.

@mritter0
If you're looking for examples you could visit https://github.com/jens-maus/yam and look at src/tcp/Connection.c to see if that helps.

why not just send a "ping" to a server you know and wait a little time for an answer ? if network is up you will get a ping back from the site, if network is down you will get an instant error.