问题
Is there an in-built function in Ruby to read the whole file without using any loop? So far, I have only come across methods that read in chunks (line or character).
回答1:
IO.read("filename")
or
File.read("filename")
回答2:
File.readlines("filename")
This is also a great method to read everything from a file and break split on carriage returns. The return is an Array with one line per element.
回答3:
Please ignore advice which states "You should never slurp (which is the annoying term for this) a file". Sometimes this is a very useful, and sensible thing to do.
Suppose you're reading a file repeatedly : good chance that reading the file into an array is a sensible optimisation over reading the file line by line, even taking into account that the o/s will cache the file.
来源：https://stackoverflow.com/questions/3328495/how-to-read-whole-file-in-ruby