Monday, May 28, 2012

Mac OS X Terminal shortcut keys

Terminal is one of the most frequently using application everyday but I have never had a chance to master its short keys. Today is a good day to start.

As I know, Terminal's short keys come from Emac, when I refer to meta short keys it means that you can use esc button or setting option(alt) button as a meta key. (Settings > Keyboard > Use option as meta key)

  • Ctrl + a = Go to the beginning of the line
  • Ctrl + e = Go to the end of the line
  • Ctrl + l or Command + k = Clear screen
  • Ctrl + r = Search for previous commands (pressing more r to get earlier commands)
  • Ctrl + w = Delete the word before cursor
  • Meta + d = Delete the word after the cursor
  • Ctrl + u = Clear the line before cursor
  • Ctrl + k = Clear the line after cursor
  • Meta + t = Swap last 2 words before cursor
  • Ctrl + d = Delete a character after cursor
  • Meta + f = Move cursor to the right one word
  • Meta + b = Move cursor to the left one word

Monday, May 14, 2012

Things I Didn't Know Rails Could Do

Something I thing it's easy and useful to me from James Edward Gray II presentation in RailsConf 2012
Ten Things You Didn't Know Rails Could Do


  • rails c --sandbox
  • rake db:migrate:status
  • pluck
    • User.pluck(:email)
    • User.uniq.pluck(:email)
  • Count Record in Group
    • Model.group(:column).count
  • File.atomic_write
  • { nested: { a: 1 } }.deep_merge(nested: { b: 2 })
  • hash.except(:key1, :key2)
  • hash1.reverse_merge(hash2) # keep hash1 value if hash2 has a duplicate key
  • content_tag_for(:tag, array) { |e| # content_inside }
  • render partial: @active_record_model & to_partial_path
  • grouped_options_for_select

Config number of file descriptors on Linux

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