install_R_deps.sh

#!/bin/bash

echo "i <- rownames(installed.packages())" > __tmp__.R

grep -oh --include=\*.{Rmd,R} -r * -e "\(library\|require\)([A-Za-z0-9.]\+)" | \
    sed 's_library(_"_'  | \
    sed 's_require(_"_'  | \
    sed 's_)_",_'        | sort | uniq | \
    perl -p -e 's/\n/ /' | \
    sed 's_^_new <- c(_' | \
    sed  's_, *$_)_' \
         >> __tmp__.R

echo >> __tmp__.R
echo "install.packages(new[!new %in% i])" >> __tmp__.R

# For debugging
#cat __tmp__.R

R --quiet -e "source('__tmp__.R')"

rm __tmp__.R

When setting up a new computer, or installing a new version of R, you may need to install many packages from existing code. This can be somewhat frustrating if your library or require calls are spread about, leading you to run your build script repeatedly as you keep erroring.

This script examines all .R and .Rmd under the current directory (recursive), extracts any packages loaded via library or require, and installs them if they are not already installed.

Some updates: Fix to missing newline (L14); reduce length of input string (L8).