从 Ruby 运行命令显示并捕获输出 [英] Running a command from Ruby displaying and capturing the output

问题描述

有什么方法可以从 Ruby 显示运行(shell)命令并捕获输出?也许在一些宝石的帮助下?

Is there some way to run a (shell) command from Ruby displaying but also capturing the output? Maybe with the help of some gem?

我所说的显示不是在最后打印它，而是当它出现时，所以用户在运行缓慢的命令时会得到正在发生的事情的反馈.

What I mean by displaying is not printing it at the end, but as it appears, so the user gets the feedback of what's going on when running slow commands.

推荐答案

你可以像这样运行系统调用:

You can run system call like this:

`sleep --help`

或者像这样

system "sleep --help"

或

%x{ sleep --help }

在system的情况下，它会打印输出并返回true或nil，其他两种方法将返回输出

In case of system it will print output and return true or nil, other two methods will return output

PS 哦.这是关于实时显示.

PS Oh. It is about displaying in real time.

所以.你可以使用这样的东西:

So. You could use something like this:

system("ruby", "-e 100.times{|i| p i; sleep 1}", out: $stdout, err: :out)

要实时打印数据并将其存储在变量中:

To print data in realtime and store it in variable:

output = []
r, io = IO.pipe
fork do
  system("ruby", "-e 3.times{|i| p i; sleep 1}", out: io, err: :out)
end
io.close
r.each_line{|l| puts l; output << l.chomp}
#=> 0
#=> 1
#=> 2
p output
#=> ['0', '1', '2']

或者使用popen

output = []
IO.popen("ruby -e '3.times{|i| p i; sleep 1}'").each do |line|
  p line.chomp
  output << line.chomp
end
#=> '0'
#=> '1'
#=> '2'
p output
#=> ['0', '1', '2']

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