I am trying to repeat socket example in ?socketConnection Server process : con1 <- socketConnection(port = 6011, server = TRUE) while(TRUE) { writeLines("aaaaa",con1 ); Sys.sleep(1) } Client process con2 <- socketConnection(Sys.info()["nodename"], port = 6011) readLines(con2, n = 1 ) while(isIncomplete(con2)) { msg <- readLines(con2, n = 1 ) if(!(is.character(msg) && length(msg) == 0)) { cat("msg = "); print(msg) } } I have two problems 1- client side isIncomplete(con2) is always return FALSE and while loop ends 2- client while loop works if I use isOpen(con2) but if server dies client loop doesn't exit ?