LabVIEW
How to tell if computer is connected to Internet?
I can certainly tell you that different OSes behave different with respect to issuing the command-line ping command. On Windows it send out 4 pings. On Unix it keeps pinging until you press Control-C. Since you want something that's cross-platform, then sending a ping command isn't the way to do it. Also, since you're looking for something that's cross-platform your best bet is to do it with the built-in TCP/IP functions. Unless you go with the Internet Toolkit (or whatever its name is now), as that may have something in it, but you have to buy that.
Keep in mind that the TCP Open Connection will give you an error if it can't make a connection, so you can use that to indicate whether you have connectivity to the web server. It's not the same as telling you whether you're "generally" connected to the internet, but that shouldn't matter since it's connection to the web server that you need.
If you want to perform a quick check to, say, have your program behave differently if you can see the web server. So, you could try something as simple as this:
Keep in mind that the TCP Open Connection will give you an error if it can't make a connection, so you can use that to indicate whether you have connectivity to the web server. It's not the same as telling you whether you're "generally" connected to the internet, but that shouldn't matter since it's connection to the web server that you need.
If you want to perform a quick check to, say, have your program behave differently if you can see the web server. So, you could try something as simple as this:
Message Edited by smercurio_fc on 06-07-2007 11:44 AM
