Creating comma delimited lists from integer values

I have a bunch of sensors attached to an arduino and I want to assemble their values into a comma delimited list, similar to the javascript array.toString() function. I'm assuming that will end up as a properly terminated char array. If that's the case, how could I then get the length of the string dynamically?

I'm trying to send the values to another devices using the RFM12b modules which require a buffer length. Depending on the situation, there may be more or less sensors attached. I want to test for their existence then include their values in the list only if they are there so I don't necessarily know what the buffer size is going to be before I start.

I'm new to C. Thanks for your patience and willingness to help.

I should probably also mention that I could use some help parsing the comma delimited lists back out on the other side :)

There is really no reason to store it as a comma separated string in the Arduino, if you aren't going to use it.

As you send the values simply insert a comma character between each value.

Then, on the other end, use strtok() to take the string apart.