get_route_info()

The goal of get_route_info() is to read pre-computed routing information from the file routeinfo.txt. Each line in this file contains the source node, destination node, next hop, and cost — all separated by semicolons. For example, the file might look like this:

nodeA;nodeB;nodeB;5
nodeA;nodeC;nodeB;8
nodeA;nodeD;nodeB;12
nodeB;nodeC;nodeC;3
nodeC;nodeD;nodeD;4

Each line means: To reach the destination from the source node, forward the packet to the next hop with the given cost.

How do we do this?

To load routing info from the file and store it in the routing table, you need to:

1. File I/O:

   • Open the file using fopen().

2. Input Parsing:

   • Use fgets() to read each line.

   • Use sscanf() to extract the source node, destination node, next hop, and cost.

3. Routing Table Update:

   • Loop through the list of nodes to find the source node.

   • Then loop again to find the destination node index.

   • Store the destination, next hop, and cost in the routing table at the correct position.

4. Return:

   • Return 0 on success, or 1 if the file could not be opened.