Ruby提供了另一种处理STDIN的方法:-n标志。它将整个程序视为在STDIN上的循环中(包括作为命令行参数传递的文件)。参见以下一行脚本:

#!/usr/bin/env ruby -n

#example.rb

puts "hello: #{$_}" #prepend 'hello:' to each line from STDIN

#these will all work:
# ./example.rb < input.txt
# cat input.txt | ./example.rb
# ./example.rb input.txt

你也可以使用STDIN。each_line和STDIN.each_line。To_a将其作为数组获取。

e.g.

STDIN.each_line do |line|
  puts line
end

以下是我在收藏的一些不知名的Ruby代码中发现的一些东西。

因此，在Ruby中，Unix命令的简单无铃实现 猫会是: # !/usr/bin/env红宝石 把ARGF.read ——https://web.archive.org/web/20080725055721/http: / / www.oreillynet.com/ruby/blog/2007/04/trivial_scripting_with_ruby.html评论- 565558

ARGF在输入方面是你的朋友;它是一个虚拟文件，从命名文件或STDIN中获取所有输入。

ARGF.each_with_index do |line, idx|
    print ARGF.filename, ":", idx, ";", line
end

# print all the lines in every file passed via command line that contains login
ARGF.each do |line|
    puts line if line =~ /login/
end

Thank goodness we didn’t get the diamond operator in Ruby, but we did get ARGF as a replacement. Though obscure, it actually turns out to be useful. Consider this program, which prepends copyright headers in-place (thanks to another Perlism, -i) to every file mentioned on the command-line: #!/usr/bin/env ruby -i Header = DATA.read ARGF.each_line do |e| puts Header if ARGF.pos - e.length == 0 puts e end __END__ #-- # Copyright (C) 2007 Fancypants, Inc. #++ — http://blog.nicksieger.com/articles/2007/10/06/obscure-and-ugly-perlisms-in-ruby

信贷:

https://web.archive.org/web/20080725055721/http://www.oreillynet.com/ruby/blog/2007/04/trivial_scripting_with_ruby.html#comment-565558 http://blog.nicksieger.com/articles/2007/10/06/obscure-and-ugly-perlisms-in-ruby

也许是这样的?

#/usr/bin/env ruby

if $stdin.tty?
  ARGV.each do |file|
    puts "do something with this file: #{file}"
  end
else
  $stdin.each_line do |line|
    puts "do something with this line: #{line}"
  end
end

例子:

> cat input.txt | ./myprog.rb
do something with this line: this
do something with this line: is
do something with this line: a
do something with this line: test
> ./myprog.rb < input.txt 
do something with this line: this
do something with this line: is
do something with this line: a
do something with this line: test
> ./myprog.rb arg1 arg2 arg3
do something with this file: arg1
do something with this file: arg2
do something with this file: arg3

似乎大多数答案都假设参数是包含要添加到stdin的内容的文件名。以下的一切都被视为只是论点。如果STDIN来自TTY，那么它将被忽略。

$ cat tstarg.rb

while a=(ARGV.shift or (!STDIN.tty? and STDIN.gets) )
  puts a
end

参数或stdin都可以为空或有数据。

$ cat numbers 
1
2
3
4
5
$ ./tstarg.rb a b c < numbers
a
b
c
1
2
3
4
5

简单快捷:

STDIN.gets.chomp == 'YES'