Last Updated: February 25, 2016
· Chip Castle

Ruby gem docs from shell to browser


Let's say I'm interested in learning more about a particular Ruby gem, but I'd prefer to read the documentation using a web browser.

A starter example

I'll run this little command to find out more about pdf-reader:

gem list pdf-reader -d

The output

*** LOCAL GEMS ***

pdf-reader (1.3.0, 1.2.0, 1.1.1)
Author: James Healy
Installed at 
(1.3.0): /Users/chip/.rvm/gems/ruby-1.9.3-p194
(1.2.0): /Users/chip/.rvm/gems/ruby-1.9.3-p194
(1.1.1): /Users/chip/.rvm/gems/ruby-1.9.3-p194

A library for accessing the content of PDF files

Full example

Since most gem authors include a Homepage for their
documentation, using this tiny mixture of Unix commands will do
the trick (line continuation character used only for formatting):

gem list pdf-reader -d | grep Home | \
awk '{ print $2 }' | xargs open

For more UNIX tips, please check out
Learning the UNIX Command Line.