/etc/puppet/modules/file_modify/lib/puppet/parser/functions/ # cat fileModify.rb
module Puppet::Parser::Functions
  newfunction(:fileModify) do |args|
    filename = args[0]
    oldline = args[1]
    newline = args[2]
    file = File.open(file, 'r+')
    file.each {|line|
      if (oldline == line)
        print "here1"
        #notify {'stuff': message => "\"#{newline}\" not equal to \"#{line}\""; }
      else
        print "here2"
        #notify {'stuff': message => "\"#{newline}\" not equal to \"#{line}\""; }
     end
    }
  end
end


/etc/puppet/manifests/ # cat site.pp
node /thing/ {
  file {
    "/tmp/thing_testing-file_modify": ensure => present,
  }
  fileModify('/tmp/thing_testing-file_modify', "-e date", "date")
  file_modify { stuff:
    file => "/tmp/thing_testing-file_modify",
    line => "date",
    ensure => present,
  }
}





~/ # cat /tmp/thing_testing-file_modify
date
date
-e date
-e date
date
date
date
date
date
date
date
date
date
date
date
date