Did you read that website? The server described there is written in C, not a shell script, since shells usually can't do socket operations (bash can do them, but that's more of an exception than anything AFAIK)
How exactly will the data be transfered from the GPS device to the computer? Is the connection initiated by the device or the computer? Is any conversion of the data necessary? Is the connection IP based (Ethernet/WiFi/Firewire) or something like USB or RS232?