= 'rufus-treechecker'

== what is it ?

Initialize a Rufus::TreeChecker and pass some ruby code to make sure it's safe before calling eval().


== getting it

gem install -y rufus-treechecker

or download[http://rubyforge.org/frs/?group_id=4812] it from RubyForge.


== usage

The treechecker uses ruby_parser (http://rubyforge.org/projects/parsetree)
to turn Ruby code into s-expressions, the treechecker then
checks this sexp tree and raises a Rufus::SecurityError if an excluded pattern
is spotted.

The excluded patterns are defined at the initialization of the TreeChecker
instance by listing rules.

require 'rubygems'
require 'rufus-treechecker'

tc = Rufus::TreeChecker.new do
exclude_fvcall :abort
exclude_fvcall :exit, :exit!
end

tc.check("1 + 1; abort") # will raise a SecurityError
tc.check("puts (1..10).to_a.inspect") # OK


Nice, but how do I know what to exclude ?

require 'rubygems'
require 'rufus-treechecker'

Rufus::TreeChecker.new.ptree('a = 5 + 6; puts a')

will yield

"a = 5 + 6; puts a"
=>
[:block,
[:lasgn, :a, [:call, [:lit, 5], :+, [:array, [:lit, 6]]]],
[:fcall, :puts, [:array, [:lvar, :a]]]
]


For more documentation, see http://github.com/jmettraux/rufus-treechecker/tree/master/lib/rufus/treechecker.rb


== dependencies

the 'ruby_parser' gem by Ryan Davis.


== mailing list

On the Rufus-Ruby list[http://groups.google.com/group/rufus-ruby] :

http://groups.google.com/group/rufus-ruby


== issue tracker

http://rubyforge.org/tracker/?atid=18584&group_id=4812&func=browse


== source

http://github.com/jmettraux/rufus-treechecker

git clone git://github.com/jmettraux/rufus-treechecker.git


== author

John Mettraux, [email protected],
http://jmettraux.wordpress.com


== the rest of Rufus

http://rufus.rubyforge.org


== license

MIT