utils (version 3.3.1)

chooseCRANmirror: Select a CRAN Mirror

Description

Interact with the user to choose a CRAN mirror.

Usage

chooseCRANmirror(graphics = getOption("menu.graphics"), ind = NULL, useHTTPS = getOption("useHTTPS", TRUE), local.only = FALSE)
getCRANmirrors(all = FALSE, local.only = FALSE)

Arguments

graphics

Logical. If true, use a graphical list: on Windows or the OS X GUI use a list box, and on a Unix-alike use a Tk widget if package tcltk and an X server are available. Otherwise use a text menu.

ind

Optional numeric value giving which entry to select.

useHTTPS

Whether to prefer HTTPS mirrors.

all

Logical, get all known mirrors or only the ones flagged as OK.

local.only

Logical, try to get most recent list from the CRAN master or use file on local disk only.

Value

None for chooseCRANmirror(), this function is invoked for its side effect of updating options("repos").getCRANmirrors() returns a data frame with mirror information.

Details

A list of mirrors is stored in file ‘R_HOME/doc/CRAN_mirrors.csv’, but first an on-line list of current mirrors is consulted, and the file copy used only if the on-line list is inaccessible.

This function is called by a Windows GUI menu item and by contrib.url if it finds the initial dummy value of options("repos"). The useHTTPS argument defaults to TRUE. With useHTTPS = TRUE, HTTPS mirrors will be offered in preference to HTTP mirrors (which are listed in a sub-menu). If it is set to FALSE, no HTTPS mirrors will be offered. Choosing an HTTPS mirror provides some guarantees on the identity of the site chosen and so is recommended. (However, most but not all R builds support downloading from HTTPS sites.)

ind chooses a row in the list of current mirrors, by number. It is best used with local.only = TRUE and row numbers in ‘R_HOME/doc/CRAN_mirrors.csv’.

See Also

setRepositories, chooseBioCmirror, contrib.url.