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[Rails] Good Random Positive Integer

♦ Written by Frank Rietta

Tonight I needed a quick way to generate a good pseudo random number. The following statement in Ruby will generate a positive integer between 0 and the maximum integer supported on the system.

1

  SecureRandom.random_number((2**(0.size * 8-2)-1))

Running that 10 times as a test on my system returned:

  • 479960941838047707
  • 4598189742420362323
  • 4319555246297899788
  • 79907720343840910
  • 1019099276589074756
  • 1753578159791031009
  • 51485412595337811
  • 3333462064391733874
  • 2622897372121370782
  • 4287564549349999056

That’s all for tonight.

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About Frank Rietta

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Frank Rietta is a web application security architect, author, and speaker. He is a computer scientist with a Masters in Information Security from the College of Computing at the Georgia Institute of Technology. He speaks about security topics and was a contributor to the security chapter of the 7th edition of the "Fundamentals of Database Systems" textbook published by Addison-Wesley.

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