| #!/usr/bin/env sh | |
| # Copy public key to authorized_keys of a remote machine | |
| if [ -z $1 ];then | |
| echo "Usage" | |
| echo "ssh-copy-id hostname /path/to/public/key" | |
| exit | |
| fi | |
| if [ -z $2 ]; then | |
| KEYCODE=`ssh-add -L` |
| git log HEAD^..HEAD --format="%an pushed change %h on %aD.%n%nWhat's in this change?%n%s%n" |
| class Array | |
| def flatten_hashes | |
| Hash[*self.map(&:to_a).flatten] | |
| end | |
| end | |
| [{:a => 'alpha'}, {:b => 'beta'}, {:c => 'charlie'}].flatten_hashes | |
| #=> {:a => 'alpha', :b => 'beta', :c => 'charlie'} |
| {:a => 'alpha'}.to_a | |
| #=> [[:a, "alpha"]] # Notice the nested array | |
| Hash[:a => 'alpha'] | |
| #=> {:a => 'alpha'} | |
| Hash[[:a => 'alpha']] | |
| #=> {} # Doesn't work with a nested array. | |
| Hash[[[:a => 'alpha']]] |
| [:a, :b, :c].map {|e| e.to_s } | |
| #=> ['a', 'b', 'c'] # Invoke .to_s on each element and collect these in an array. | |
| [:a, :b, :c].map(&:to_s) | |
| #=> ['a', 'b', 'c'] # The same result obtained in a shorthand fashion. |
| lambda{|*args| args}.call(1, 2) | |
| #=> [1, 2] | |
| # This is the splat operator used in the 'collecting mode'. | |
| # The splat before the args ensured that all arguments were marshalled into an Array. | |
| [1, 2, [3, 4]] | |
| #=> [1, 2, [3, 4]] | |
| [1, 2, *[3, 4]] | |
| #=> [1, 2, 3, 4] | |
| # This is the unmarshalling 'mode' of the splat operator. |
| [{:a => 'alpha'}, {:b => 'beta'}, {:c => 'charlie'}].map(&:to_a) | |
| #=> [[[:a, "alpha"]], [[:b, "beta"]], [[:c, "charlie"]]] | |
| flat_array = [{:a => 'alpha'}, {:b => 'beta'}, {:c => 'charlie'}].map(&:to_a).flatten | |
| #=> [:a, "alpha", :b, "beta", :c, "charlie"] | |
| Hash[*flat_array] | |
| #=> {:a=>"alpha", :b=>"beta", :c=>"charlie"} | |
M stands for the Meta key. Commonly represented by the Alt/Option/Esc key on your keyboard.
C stands for the Control key.
Example -- C-k means 'hit k while keeping Control pressed.'
M-.
Yank the last argument to the previous command.
M-C-y
Yank the first argument to the previous command.
| #"Find the greatest product of five consecutive digits in the 1000-digit number." | |
| # http://projecteuler.net/problem=8 | |
| big = "7316717653133062491922511967442657474235534919493496983520312774506326239578318016984801869478851843858615607891129494954595017379583319528532088055111254069874715852386305071569329096329522\ | |
| 74430435576689664895044524452316173185640309871112172238311362229893423380308135336276614282806444486645238749303589072962904915604407723907138105158593079608667017242712188399879790879227492190169\ | |
| 97208880937766572733300105336788122023542180975125454059475224352584907711670556013604839586446706324415722155397536978179778461740649551492908625693219784686224828397224137565705605749026140797296\ | |
| 86524145351004748216637048440319989000889524345065854122758866688116427171479924442928230863465674813919123162824586178664583591245665294765456828489128831426076900422421902267105562632111110937054\ | |
| 4217506941658960408071984038509624554443629812309878799272442849091888458015616609791913387549920052406368991 |
| p [1..999].select{|e| e%3 == 0 || e%5 == 0}.inject(:+) |