Find a TCP port that can be opened
freePort(ports = 1024:65535, default = "random", randomize = TRUE)Returns an integer representing the first port among ports that
can be opened. If none can be opened, then default is returned.
If port querying is not supported, as in R (< 4.0.0), then default
is returned.
(integer vector, or character string)
Zero or more TCP ports in [0, 65535] to scan.
If "random", then a random set of ports is considered.
If "auto", then the port given by environment variable
R_PARALLEL_PORT is used, which may also specify random.
(integer) NA_integer_ or a port to returned if
an available port could not be found.
If "first", then ports[1]. If "random", then a random port
among ports is used. If length(ports) == 0, then NA_integer_.
(logical) If TRUE, ports is randomly shuffled
before searched. This shuffle does not forward the RNG seed.