如何在Scala actor中执行（执行）外部系统命令？ [英] how to execute (exec) external system commands in Scala actor?

问题描述

要运行外部命令，我应该

to run an external command, I should

import sys.process._
val result="ls a" !

然后在使用actor时，我还需要使用！发送消息。所以！是在actor和过程中都定义的，但是我需要在同一代码块中同时使用它们，该怎么做？

then when use actor, I need to also use "!" to send message. So ! is defined both in actor and in process, but I need to use them both in the same code block, how to do that?

推荐答案

我看不到 Process 和 ActorRef 都定义同名方法的问题。

I don't see the issue of Process and ActorRef both defining a method with the same name.

一个类似的例子是

class A { def ! = println("A") }
class B { def ! = println("B") }
val a = new A
val b = new B
a.! // "A"
b.! // "B"

完全没有名称冲突或歧义。

There's no name collision or ambiguity at all.

您唯一需要担心的是从 String 到 Process的隐式转换。

The only thing you have to worry about is the implicit conversion from String to Process.

foo。！之所以起作用是因为 Process 是唯一可以将 String 隐式转换为定义！方法的类。

"foo".! works because Process is the only class in which String can implicitly be converted to that defines a ! method.

如文档所述，如果您改用 foo .lines 之类的东西，则编译器会得到混淆，因为它不知道是将 String 转换为 Process 还是转换为 StringLike ，因为两者都定义了行方法。

As the documentation says, if you instead use something like "foo".lines, then the compiler gets confuse because it doesn't know whether to convert String to Process or to StringLike, since both define a lines method.

但是-再次-这不是您的情况，您可以放心地执行以下操作：

But - again - this is not your case, and you can safely do something like:

"ls".!
sender ! "a message"

编译器不应抱怨。

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