| make.socket {utils} | R Documentation |
Create a Socket Connection
Description
With server = FALSE attempts to open a client socket to the
specified port and host. With server = TRUE the R process
listens on the specified port for a connection and then returns a
server socket. It is a good idea to use on.exit to
ensure that a socket is closed, as you only get 64 of them.
Usage
make.socket(host = "localhost", port, fail = TRUE, server = FALSE)
Arguments
host |
name of remote host |
port |
port to connect to/listen on |
fail |
failure to connect is an error? |
server |
a server socket? |
Value
An object of class "socket", a list with components:
socket |
socket number. This is for internal use. On a Unix-alike it is a file descriptor. |
port |
port number of the connection. |
host |
name of remote computer. |
Warning
I don't know if the connecting host name returned
when server = TRUE can be trusted. I suspect not.
Author(s)
Thomas Lumley
References
Adapted from Luke Tierney's code for XLISP-Stat, in turn
based on code from Robbins and Robbins “Practical UNIX Programming”.
See Also
Compiling in support for sockets was optional prior to R 3.3.0: see
capabilities("sockets") to see if it is available.
Examples
daytime <- function(host = "localhost"){
a <- make.socket(host, 13)
on.exit(close.socket(a))
read.socket(a)
}
## Official time (UTC) from US Naval Observatory
## Not run: daytime("tick.usno.navy.mil")