The solution that immediately jumped into my mind was something like “abc”.map {…}. The first problem here is #map is based on #each, and String#each will iterate on lines instead of characters. So “abc”.map {…} will have only 1 iteration, which give you access to “abc” as a whole inside the iteration.

It’s natural that I then went to String#each_byte for help. “abc”.each_byte {…} will iterate on characters. The problem with each_byte is its return value is the string itself, instead of the result after processing like map. We can’t get a one-line solution with each_byte:

res = []

"abc".each_byte {|i| res << i}

res.map {|i| i.to_s(16)}

3 lines for a simple problem! Ugly, right?

Then I remembered the swissarmy knife of ruby: String#unpack. String#unpack takes a string as directives and applies those directives on its caller. Its caller, a string, is used as a (binary) data stream in this process. For example:

"a".unpack('c') # => [97]

‘c’ is a directive which will extract a character as an integer. You can apply many directives at the same time, like:

"abc".unpack('cH') # => [97, "6"]

which will execute ‘c’ on the first character, and ‘H’ on the second. You can append a number or ‘*’ to a directive so it will be executed many times:

"abc".unpack('c2') # => [97, 98]

"abc".unpack('c*') # => [97, 98, 99]

And String#unpack provides us a directive to extract characters into a hex digit! Here’s the solution using unpack to my friend’s question:

"abc".unpack('H*')

There are many directives you can use in unpack. Whenever you want to transform a string into another common format, like ascii, base64, please give String#unpack a glance, it may resolve your problem instantly.

For example:

testdata = [
  { :name => "Haruhi", :gender => "F", :role => "Brigade Leader" },
  { :name => "Mikuru", :gender => "F", :role => "Time Traveler" },
  { :name => "Yuki",   :gender => "F", :role => "Humanoid Interface" },
  { :name => "Haruhi", :gender => "M", :role => "ESPer" },
  { :name => "Kyon",   :gender => "M", :role => "Normal" },
]

But you may draw a sigh or be tired because you must type same keys many times.

In this case, the following helper method will help you.

class Hash
  def self.create_with(*keys)
    rows = yield()
    return rows.collect {|row|
      hash = self.new
      keys.zip(row) {|k, v| hash[k] = v }
      hash
    }
  end
end

Using this helper method, you have to type keys only once.

testdata = Hash.create_with(:name, :gender, :role) {[
  [ "Haruhi", "F", "Brigade Leader"     ],
  [ "Mikuru", "F", "Time Traveler"      ],
  [ "Yuki",   "F", "Humanoid Interface" ],
  [ "Haruhi", "M", "ESPer"              ],
  [ "Kyon",   "M", "Normal"             ],
]}

p testdata[0]  #=> {:gender=>"F", :role=>"Brigade Leader", :name=>"Haruhi"}

It is a good idea to use YAML format instead of array of arrays.

require 'yaml'
arrays = YAML.load <<END
- [ Haruhi, F, Brigade Leader     ]
- [ Mikuru, F, Time Traveler      ]
- [ Yuki,   F, Humanoid Interface ]
- [ Haruhi, M, ESPer              ]
- [ Kyon,   M, Normal             ]
END
testdata = Hash.create_with(:name, :gender, :role) { arrays }

p testdata[0]  #=> {:gender=>"F", :role=>"Brigade Leader", :name=>"Haruhi"}

I hope this helps your Ruby life.

Installing of the perl subversion binding solved this problem.

You setup your certificate in apache config file

I tried: http://www.postfix.org/faq.html#null_client But I seems not work.

After check out the postfix log:

Even you set

local_transport = error:local delivery is disabled
But when you have aliasmaps, aliasdatabase, virtualaliasmaps. Postfix will still try to find the alias name in local. So it fails when it can not find it.

main.cf

master.cf

And Another thing, make sure your hostname is NOT your domain. because It will check hostname first and mx record? I guess.