what is ERb?

[Maggie Q.]

ERb means Embeded Ruby, and it is probably the coolest tools used on Ruby. ERb was written by Seki Masatoshi. Its major use is to put Ruby code inside an HTML file. ERb reads from word to word. At some point when it reads the Ruby code embedded in the document it sees that it has to fill in a blank.

[Martin]

Thank you for sharing that information. I would like to add few points about ERB.
Embedded Ruby or ERB or eRuby is a templating system. It is similar to ASP, JSP and PHP.

There are several implemetations of eRuby:-
eruby - It is an implementation written in C Programming Language.
erb - It is an implementation purely written in Ruby Programming Language.
erubis - It is an implementation purely written in Ruby as well as in Java. It is fastest of all 3 implementations.

[carl owen]

In order to automatically parse Ruby-embedded which are using Eruby as PHP does, you can setup an Apache web server.

Follow the steps given below so that you can use Eruby with Apache web server :

1. First, in the cgi-bin directory, copy Eruby binary and add the lines given below to httpd.conf:

AddType application/x-httpd-eruby .rhtml
Action application/x-httpd-eruby /cgi-bin/eruby

Note : If you would like to include index.rhtml, you can replace or add DirectoryIndex directive. If you do this, you will be able to create directory listings for directories that do not contain index.html by using Ruby.

2. Now, if you have done the above correctly and if you enter the following directive, even if index.html and index.shtml do not exist in the directory, the embedded Ruby script index.rhtml would be searched.

DirectoryIndex index.html index.shtml index.rhtml

Important : You can also use a site wide Ruby script.

DirectoryIndex index.html index.shtml /cgi-bin/index.rb

Congratulations!! you are done

After the above steps are followed properly, you will be able to generate forms and dynamic content as you can write HTML documents which contain Embedded Ruby.

[BlueGigs]

I don't know much about Ruby. What sort of applications is it best suited for? When and why would I use an application written in Ruby, rather than a more familiar language (i.e. JSP)?