Imagine a big treasure hunt in a busy park. This Go code is like a special pair of binoculars that helps you find clues by looking for certain flags or signals from other treasure hunters.
What the Code Does
Setting Up the Binoculars:
The code gets ready to use the special binoculars (pcap.OpenLive).
It sets the binoculars to a specific mode to look for specific flags or signals (handle.SetBPFFilter). Think of it like adjusting the focus on the binoculars to only see flags of a certain color.
Scanning the Park:
The code starts scanning the park with the binoculars (gopacket.NewPacketSource). It's like looking all around for any sign of the special flags.
Identifying Clues:
Every time the binoculars spot a flag or signal, the code checks to see if it's a clue (networkLayer, transportLayer). This is like looking for a specific pattern or symbol on the flag.
If the flag isn't a clue, the code ignores it and keeps looking.
Keeping Track of Clues:
When the code finds a real clue, it writes it down in a notebook (results[srcPort] += 1). This is like making a tally mark next to the name of the person who sent the clue.
Important Words
Package: Think of this as a backpack full of tools for the code to use. It contains special tools made by other people for finding clues in the park.
Import: This is like taking out the right tools from the backpack.
Variables: These are like labels for important things in the code. "filter" is the label for the special flag the code is looking for.
Functions: These are like little instructions the code follows. "capture" is the main set of instructions, telling the code how to use the binoculars to find clues.
In Summary:
This Go code is a way to listen to conversations (network traffic) happening on your computer (the "park") and look for specific messages (the "flags") that are part of a specific type of communication (TCP). It can be used to troubleshoot network issues or analyze traffic patterns.