1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133
|
#' Find an open TCP port
#'
#' Finds a random available TCP port for listening on, within a specified range
#' of ports. The default range of ports to check is 1024 to 49151, which is the
#' set of TCP User Ports. This function automatically excludes some ports which
#' are considered unsafe by web browsers.
#'
#' @inheritParams runServer
#' @param min Minimum port number.
#' @param max Maximum port number.
#' @param n Number of ports to try before giving up.
#'
#' @return A port that is available to listen on.
#'
#' @examples
#' \dontrun{
#' s <- startServer("127.0.0.1", randomPort(), list())
#' browseURL(paste0("http://127.0.0.1:", s$getPort()))
#'
#' s$stop()
#' }
#'
#' @export
randomPort <- function(min = 1024L, max = 49151L, host = "127.0.0.1", n = 20) {
min <- max(1L, min)
max <- min(max, 65535L)
valid_ports <- setdiff(seq.int(min, max), unsafe_ports)
n <- min(n, length(valid_ports))
# Try up to n ports
try_ports <- if (n < 2) valid_ports else sample(valid_ports, n)
for (port in try_ports) {
if (is_port_available(port, host)) {
return(port)
}
}
error_unavailable_port()
}
is_port_available <- function(port, host = "127.0.0.1") {
tryCatch(
{
s <- startServer(host, port, list(), quiet = TRUE)
s$stop()
TRUE
},
error = function(e) FALSE
)
}
error_unavailable_port <- function(message = "Cannot find an available port.") {
stop(
structure(
list(message = message, call = sys.call(-1)),
class = c("httpuv_unavailable_port", "error", "condition")
)
)
}
# Ports that are considered unsafe by Chrome
# http://superuser.com/questions/188058/which-ports-are-considered-unsafe-on-chrome
# https://github.com/rstudio/shiny/issues/1784
unsafe_ports <- c(
1,
7,
9,
11,
13,
15,
17,
19,
20,
21,
22,
23,
25,
37,
42,
43,
53,
77,
79,
87,
95,
101,
102,
103,
104,
109,
110,
111,
113,
115,
117,
119,
123,
135,
139,
143,
179,
389,
427,
465,
512,
513,
514,
515,
526,
530,
531,
532,
540,
548,
556,
563,
587,
601,
636,
993,
995,
2049,
3659,
4045,
6000,
6665,
6666,
6667,
6668,
6669,
6697
)
|