I have been playing around with erb from the command line recently. I wanted to make a dirt simple erb template, for example the following:
<%- name = "Joe"; quality = "fantastic" -%>
Hello. My name is <%= name %>. I hope your day is <%= quality %>.
This works if I run
erb -T - thatfile.erb
what I want to do is to make name and quality be passable from command line arguments, so that I could do something like:
./thatfile.erb "Bill" "super"
from the bash prompt and do the same thing.
I am aware that I could write a ruby script that would just read that template in and then use ERB.new(File.read("thatfile.erb")).result(binding), or writing the template after an END and doing likewise, but I'm looking for a more lightweight approach if it exists, because I don't want to write two files for each erb script that I create for this purpose.
If you are using unix, try following:
$ cat 1.erb
Hello. My name is <%= name %>. I hope your day is <%= quality %>.
$ (echo '<% name="Joe"; quality="fantastic" %>' && cat 1.erb) | erb
Hello. My name is Joe. I hope your day is fantastic.
Alternatively, you can use a ruby script and load it in as a library.
# vars.rb
@hello = 'kirk'
# template.html.erb
<div><%= @hello %></div>
$ erb -r './vars' template.html.erb
I went with the BASH command-line shortcut for environmental variables.
Outside:
STUFF=foo,bar erb input.html.erb >output.html
Inside:
<%
stuff = ENV['STUFF'].split(',')
%>
After a few minutes e-searching I determined the other solutions are all variations on "write the erb wrapper command yourself." Could be wrong, but I ain't going back.
Please note that Ruby 2.2 and newer provide a much nicer solution that was implemented according to this:
erb var1=val1 var2=val2 my-template.erb
