Issues when reading a string from TCP socket in Node.js

Thanks everyone for the explanations, they helped me to better understand the way in which data is sent and received via TCP sockets. Below is a brief overview of the code that I used in the end:

var chunk = "";
client.on('data', function(data) {
    chunk += data.toString(); // Add string on the end of the variable 'chunk'
    d_index = chunk.indexOf(';'); // Find the delimiter

    // While loop to keep going until no delimiter can be found
    while (d_index > -1) {         
        try {
            string = chunk.substring(0,d_index); // Create string up until the delimiter
            json = JSON.parse(string); // Parse the current string
            process(json); // Function that does something with the current chunk of valid json.        
        }
        chunk = chunk.substring(d_index+1); // Cuts off the processed chunk
        d_index = chunk.indexOf(';'); // Find the new delimiter
    }      
});

Comments welcome...

You're on the right track with using a delimiter. However, you can't just extract the stuff before the delimiter, process it, and then discard what came after it. You have to buffer up whatever you got after the delimiter and then concatenate what comes next to it. This means that you could end up with any number (including 0) of JSON "chunks" after a given data event.

Basically you keep a buffer, which you initialize to "". On each data event you concatenate whatever you receive to the end of the buffer and then split it the buffer on the delimiter. The result will be one or more entries, but the last one might not be complete so you need to test the buffer to make sure it ends with your delimiter. If not, you pop the last result and set your buffer to it. You then process whatever results remain (which might not be any).