I was doing some cleaning ony my linux machine and, among others, I try to clean my R environment variables accordingly [0] and [1]. I am not really sure how to declare in a clean manner these startup variables. Here is my setup: 1- my home folder -$ ls ~/.config/R env/ helper/ Renviron Rprofile.r 2- system R install /usr/lib/R 3- user library /developement/language/r/library 4- system configuration files: (NOTE: /usr/lib/R/etc/ are symlnks to the below files) $ ls /etc/R/ javaconf ldpaths Makeconf Renviron repositories -------------------------------- Most important R environment variables for my system: R_HOME, R_LIBS, R_LIBS_SITE,R_LIBS_USER,R_ENVIRON,R_ENVIRON_USER,R_PROFILE_USER As far I can understand, in my setup, these above variables would be: R_LIBS_SITE=/usr/lib/R/library R_LIBS_USER=/developement/language/r/library R_ENVIRON=/usr/lib/R/etc/Renviron R_ENVIRON_USER=~/.config/R/Renviron R_PROFILE_USER=~/.config/R/Rprofile.r I have a doubt about two variables: R_HOME=/usr/lib/R/ right ? Is there any need to export it in my environment? R_LIBS=${R_LIBS_USER}:${R_LIBS_SITE} right ? Do I need to export all these mentioned variables in my user environment? Until now, I jsut export R_ENVIRON_USER,R_PROFILE_USER via my /etc/profile file. $ cat ~/.config/r/Renviron .... R_HOME=/usr/lib/R R_HOME_USER=/developement/language/r R_LIBS_USER=${R_HOME_USER}/library R_LIBS=${R_LIBS_USER}:${R_HOME}/library R_HISTFILE=/developement/language/r/R.Rhistory R_HELPER=/home/gabx/.config/r/helper R_HISTSIZE=5000 ............ Are the above variables correctly set ? On a R session, Sys.getenv() returns correctly everything, except R_LIBS_SITE which is empty. Why? Do I need to export it somewhere ? R_LIBS /developement/language/r/library:/usr/lib/R/library Is this the correct way for R to see R_LIBS? Then, when I upgrade packages, do I need to upgrade separatly site library and user library, or just one ligne upgardaing jusr R_LIBS? Thank you for any advice on my current variable declaration setup. [0]http://stat.ethz.ch/R-manual/R-devel/library/base/html/EnvVar.html [1]http://stat.ethz.ch/R-manual/R-devel/library/base/html/Startup.html -- google.com/+arnaudgabourygabx