Ruby/File Directory/read

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Содержание

Read 50 characters

# Put some stuff into a file.
open("sample_file", "w") do |f|
  f.write("This is line one.\nThis is line two.")
end
 
puts open("sample_file") { |f| f.read(50) }



read an arbitrary number of bytes from a file into a single variable using read:

File.open("text.txt") do |f|
  puts f.read(6)
end



Read file by chunk size

class File
  def each_chunk(chunk_size=4)
    yield read(chunk_size) until eof?
  end
end
 
open("pipe_separated_records", "w") do |f|
  f << "This is record one.|This is record two.|This is record three."
end
open("pipe_separated_records") do |f|
  f.each_chunk(2) { |chunk| puts chunk }
end



Reading the Contents of a File

# Put some stuff into a file.
open("sample_file", "w") do |f|
  f.write("This is line one.\nThis is line two.")
end
# Then read it back out.
open("sample_file") { |f| puts f.read }