how to search for valid com ports?

[more granularity]

I want to search for a com port that an instrument has been plugged into.
So I would like to go through all possible com ports, test which ones are
valid, and then test which valid port has data on it.

If I try to open a non existent com part, is there an error I can access?

When I check ERR after trying to open an invalid com port I always get 0.

Any suggestions?

TIA

[bfuller]

You might be able to make use of this code, or parts of it.

http://www.freebasic.net/forum/viewtopi ... en#p153272

If you scan all available ports to see what is happening on each perhaps ????

[Zippy]

I want to search for a com port that an instrument has been plugged into.
So I would like to go through all possible com ports, test which ones are
valid, and then test which valid port has data on it.
<snip>

Your operating system is...?

[St_W]

if you're using Windows the easiest way is to look into the registry:
HKLM\HARDWARE\DEVICEMAP\SERIALCOMM lists all ports

Sample code