There's a handy script to automate the update process that I came across
some time ago at
https://bridgewater.wordpress.com/2010/12/21/my-favorite-r-packages-installed-with-one-command/

When you run the script, it will automatically install the libraries that
you set up in the script. When you run it, it will install into the first
location in .libPaths(). If you want packages installed in ~/Library/R...,
then you need to check the "Default Library Paths" option in
R-->Preferences-->Startup. Alternatively, you could supply the lib= argument
to the install.packages() call. With a little extra code, you could even
define the install location for each package individually.

Here's a shortened version:
# Essential R packages: 2011-01-02
# Originally from: R packages I use commonly: 12/21/2010 twitter:
drbridgewater
#     Jeff S. A. Bridgewater
#
https://bridgewater.wordpress.com/2010/12/21/my-favorite-r-packages-installed-with-one-command/
#

#list all packages currently installed
p<-c()

#add essential packages:
p<-c(p,"survival")
p<-c(p,"Hmisc")
# add more packages here

# UPDATE the repository list to point to your local repositories
repositories<-c("http://mirrors.softliste.de/cran/","
http://mirrors.softliste.de/cran/")
install_package<-function(pack,repositories)
{
if(!(pack %in% row.names(installed.packages())))
{
update.packages(repos=repositories, ask=F)
install.packages(pack, repos=repositories, dependencies=T)
}
require(pack,character.only=TRUE)
}

for( pack in p)
{
install_package(pack,repositories)
}

	[[alternative HTML version deleted]]

