How can I print R documentation from a Linux command shell (e.g. bash)?

Question

How can I check documentation for R code from a Linux command shell such as bash? I DO NOT mean an interactive session.

With Perl, I can use perldoc to print out documentation at the command line:

perldoc lib

I was hoping for something simple like that for R. I don't always want to pull up a full interactive R session just to look up some documentation.

Answer 1

There might be other ways, but one that works for me is using the -e flag to execute code on the command line. I also use the --slave flag, which prevents anything from being printed to standard output (e.g. no R startup messages, etc.):

R --slave -e '?function'

I actually created a super small script I call rdoc to act like a simple R version of perldoc:

#!/bin/bash
R --slave -e "?$1"

After installing that in my ~/bin directory (or however you install it in your PATH), it's easy:

rdoc function

If you want to look at documentation of a function from a particular package, prepend the library name followed by two colons. For example, to pull up documentation of the dmrFinder function from the charm package:

rdoc charm::dmrFinder