Socket Protocol Fundamentals

Question

Recently, while reading a Socket Programming HOWTO the following section jumped out at me:

But if you plan to reuse your socket for further transfers,

Answer 1

The decision should depend on the data you want to send (what it is, how is it gathered). If the data is fixed length, then fixed length packets will probably be the best. If data can be easily (no escaping needed) split into delimited entities then delimiting may be good. If you know the data size when you start sending the data piece, then len-prefixing may be even better. If the data sent is always single characters, or even single bits (e.g. "on"/"off") then anything different than fixed size one character messages will be too much.

Also think how the protocol may evolve. EOL-delimited strings are good as long as they do not contain EOL characters themselves. Fixed length may be good until the data may be extended with some optional parts, etc.