File Access in RStudio

I've been spending a fair bit of time in RStudio Desktop recently, much of it related to my work with INFORMS Pro Bono Analytics. I really like RStudio as a development environment for R code, including Shiny apps. It does, however, come with the occasional quirk. One of those has to do with how RStudio accesses the file system.

I tripped over this a couple of times recently when I wanted to open an R file that I had dropped in the /tmp directory on my Linux Mint system. The Files tab in RStudio appeared to be limited to the directory tree under my home directory. There was no way to browse to system directories like /tmp. Similarly, there is a way to set the default working directory (Tools > Global Options... > General > Basic > R Sessions). RStudio does not let you type in a directory name (perhaps a defense against typos?), and the Browse... button will not leave your home tree.

Initially I decided this was not important enough to worry about, but then I saw a post on the Posit Community forum by someone who was stuck trying to work from home due to a related issue. So I did a little experimentation and found a workaround, at least for the first problem (accessing files in places like /tmp). If I run setwd("/tmp") in the Console tab (which sets the working directory for the current R session), then click the More menu in the Files tab and select Go To Working Directory, the Files tab now browses /tmp, and I can navigate up to the system root directory and then down to anywhere within reason.

Changing the default starting directory is not something I actually care to do, but I'll document it here in case a reader might wish to do so. You can go to the IDE configuration directory (~/.config/rstudio on Linux and OS X, %appdata%\RStudio on Windows), open the rstudio-prefs.json file in a text editor, and change the value of the "initial_working_directory" entry to whatever starting directory you want. Save it, (re)start RStudio Desktop, and hopefully you begin in the right place.