Question

I’m using cmd to print the users network spec in to a text file using ipconfig > computer.txt. An Example of this would be

Windows IP Configuration


Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . : 
   Link-local IPv6 Address . . . . . : fe80::cd7a:50b3:1284:865%12
   IPv4 Address. . . . . . . . . . . : 10.0.0.26
   Subnet Mask . . . . . . . . . . . : 255.0.0.0
   Default Gateway . . . . . . . . . : 10.0.0.1

Ethernet adapter Local Area Connection:

   Connection-specific DNS Suffix  . : 
   Link-local IPv6 Address . . . . . : fe80::5c3a:ae77:81:8cdf%11
   IPv4 Address. . . . . . . . . . . : 10.0.0.25
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   IPv4 Address. . . . . . . . . . . : 192.168.1.12
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Default Gateway . . . . . . . . . : 10.0.0.1

How would I use this to find one of the adapters default gateway( x lines down and after then:

Not sure if this is right way of doing it.

If not, what is the best way to find the subnet mask/default gateway using vb.net

Answer 1

If the format is always the same String.IndexOf and String.Substring are effcient ways:

Dim gateWays = From line In File.ReadLines("C:\Temp\data.txt")
               Skip 10
               Let gatewayIndex = line.IndexOf("Default Gateway . . . . . . . . . :")
               Where gatewayIndex > -1
               Select line.Substring(gatewayIndex + "Default Gateway . . . . . . . . . :".Length)
Dim firstGateWay = gateWays.FirstOrDefault

You can use Enumerable.Skip to skip x-lines, in this example 10.