Have you tried just parsing the output from the command "ipconfig"?
It's pretty obvious from the output that might give you if a connection is availible. I hope it helps. -Matt Dave Brueck wrote: > Cliff Wells wrote: > > I'm writing an application that needs to know if an Internet connection > > is available. > [snip] > > Is there any way to reliably determine the state of the client's > > internet connectivity? > > Hi Cliff, > > On a Win32 system you can reliably determine the state of the Internet > connection but it requires a fair amount of work. Here's the recipe I use: > > 1) If the user has a modem and is connected via a modem, you know for sure that > the user is online (use ctypes to call rasapi32.RasEnumEntriesA to see if the > user has a modem, and rasapi32.RasEnumConnectionsA to see if the user is > connected via a modem) > > 2) If that test fails, next check for open connections to remote hosts. If there > are any open connections to public IP addresses, the user is "online". (use > iphlpapi.GetTcpTable to get a list of connections, and keep only those where > dwState is MIB_TCP_STATE_ESTAB. Remove any addresses that are 127.0.0.1, 10.*, > 192.168.*, or 172.16-31.*). If after all this the list is non-empty, you're > probably online. > > 3) Still no luck? Call IcmpSendEcho to a well-known server - this sends a "ping" > packet, which won't bring up the dial-up networking box to annoy your users. I > usually start with a list of all the DNS root servers as well as pingable > company IP addresses, and randomly choose one of them. Then, anytime I make a > connection to the Internet, I save the results of the hostname lookup and use > them in my list as well (so that very few pings actually go to the DNS root > servers). Also, it's good to make sure that your code has restrictions in place > to prevent it from pinging anything too often. Due to instant messengers & email > clients, step #2 usually detects when the user is online, so the need for an > actual ping is greatly reduced. > > Anyway, after doing the above you know with a high degree of certainty whether > or not the user is online. > > The above approach is obviously a lot of work, but once you take the time to do > it you can just stick it in a library somewhere and not have to think about it > again. On import of the library, I start up a background thread that updates a > status variable every second or so, so that any time my app can query to see the > state of the Internet connection. Although it's a lot of work, I've found that > (1) it's pretty accurate and (2) it's non-intrusive (it doesn't e.g. pop up the > dial-up networking dialog box if the user is offline). > > Hope at least some of this helps, > Dave -- http://mail.python.org/mailman/listinfo/python-list
