Find a TCP port that can be opened
freePort(
ports = 1024:65535,
default = if (getRversion() >= "4.0.0") NA_integer_ else "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.