Ruby：如何在脚本中调用文件后关闭文件

Question

使用下面的脚本，close（）语法将在哪里发生？它将是什么？

print "Enter the filename you want to open here > "
filename = $stdin.gets.chomp
txt = open(filename)

puts "Here's your file #{filename}"
print txt.read
print "Type the filename again: "

file_again = $stdin.gets.chomp
txt_again = open(file_again)

print txt_again.read

Answer 1

一个人有两种能力：在ensure块内明确调用IO#close或使用IO#read / open的块版本：

filename = $stdin.gets.chomp
begin
  txt = open(filename)
  puts "Here's your file #{filename}"
  print txt.read
ensure
  txt.close
end


filename = $stdin.gets.chomp
open(filename) do |txt|
  puts "Here's your file #{filename}"
  print txt.read
end

Answer 2

您可以在上下文中使用close方法：txt.close

但我建议你使用块，这样你的代码会更好

像这样的东西

File.open(filename) do |txt|
   ...
   print txt.read
   ...
end