R fifo example

fifo.R

tf <- tempfile()
f <- fifo(tf, "w+b", blocking = TRUE)

p <- callr::r_bg(function(tf) {
        f <- fifo(tf, "wb", blocking = TRUE)
        x <- rnorm(1e6)
        b <- serialize(x, NULL)
        writeBin(length(b), f)
        writeBin(b, f)
        close(f)
    },
    list(tf = tf))

n <- readBin(f, "integer", n = 1L)
cat("n =", n, "\n")
r <- raw(0)
while (length(r) < n) {
  r <- append(r, readBin(f, "raw", n = n - length(r)))
}

length(unserialize(r))