REPL's in PHP are quite hard due to the fatal error issue, among other things. I wrote one (https://github.com/apinstein/iphp https://github.com/apinstein/iphp

REPL's in PHP are quite hard due to the fatal error issue, among other things. I wrote one (https://github.com/apinstein/iphp https://github.com/apinstein/iphp) a long time ago that got around a lot of these issues using temporary files, but his idea to use forking is really neat. I never got multi-line input working, either. I have been thinking about re-doing it with runkit, but now I'll have to play around with BORIS and see how it works.