ruby - #tty 是什么？在 STDIN 上意味着/在 ruby​​ 中做什么？

Question

阅读 ruby​​ 文档并没有多大帮助 here :

Returns true if ios is associated with a terminal device (tty), falseotherwise.

我希望得到一些额外的资源或解释来帮助我更好地理解这一点。

对于上下文，我正在编写一个小的命令行程序，它接受文件路径或管道内容到 ruby​​ 可执行文件中，并使用 #tty? 来确定传入的内容。

Answer 1

好像http://www.jstorimer.com/blogs/workingwithcode/7766125-writing-ruby-scripts-that-respect-pipelines对 #tty? 的作用提供了最简洁的描述:

Ruby's IO#isatty method (aliased as IO#tty?) will tell you whether or not the IO in question is attached to a terminal. Calling it on $stdout, for instance, when it's being piped will return false.

以下是一些您可能会觉得有用的相关信息:

• Detecting stdin content in Ruby
• How can you check for STDIN input in a Ruby script?
• https://stackoverflow.com/a/273605
• https://gist.github.com/timuruski/6072363

背景意义来自What do pty and tty mean? :

In UNIX, /dev/tty* is any device that acts like a "teletype", ie, terminal. (Called teletype because that's what we had for terminals in those benighted days.)

本着问题的精神，这里有一个从http://zetcode.com/lang/rubytutorial/io/写入/dev/tty的例子。 :

#!/usr/bin/ruby

fd = IO.sysopen "/dev/tty", "w"
ios = IO.new(fd, "w")
ios.puts "ZetCode"
ios.close