假装是 bash 中的任何命令的 tty

Pretend to be a tty in bash for any command

提问by edi9999

Whenever I use grep, and I pipe it to an other program, the --coloroption is not respected. I know I could use --color=always, but It also comes up with some other commands that I would like to get the exact output of that command as the output I would get if I was in a tty.

每当我使用grep, 并将其通过管道传输到其他程序时，该--color选项不受尊重。我知道我可以使用--color=always，但它也提出了一些其他命令，我想获得该命令的确切输出作为我在 tty 中获得的输出。

So my question is, is it possible to trick a command into thinking that the command is run inside a tty ?

所以我的问题是，是否有可能诱使命令认为该命令是在 tty 内运行的？

For example, running

例如，运行

grep --color word file # Outputs some colors
grep --color word file | cat # Doesn't output any colors

I'd like to be able to write something like :

我希望能够写出类似的东西：

IS_TTY=TRUE grep --color word file | cat  # Outputs some colors

This questionseems to have a tool that might do what I want :empty - run processes and applications under pseudo-terminal (PTY), but from what I could read in the docs, I'm not sure it can help for my problem

这个问题似乎有一个工具可以做我想做的事：在伪终端 (PTY) 下空运行进程和应用程序，但从我在文档中读到的内容来看，我不确定它是否可以解决我的问题

采纳答案by Nick Sweeting

There are a number of options, as outlined by several other Stack Overflow answers (see Caarlos's comment). I'll summarize them here though:

正如其他几个 Stack Overflow 答案所概述的那样，有许多选项（请参阅Caarlos的评论）。不过，我会在这里总结一下：

1. Use script+ printf, requires no extra dependencies:

   0<&- script -qefc "ls --color=auto" /dev/null | cat
   

   Or make a bash function fakettyto encapsulate it:

   faketty () {
       script -qfce "$(printf "%q " "$@")"
   }
   faketty ls --color=auto | cat  
   

   Or in the fish shell:

   function faketty
       script -qefc "(printf "%q " "$argv")"
   end
   faketty ls --color=auto | cat 
   

   (credit goes to this answer)

   http://linux.die.net/man/1/script

2. Use the unbuffercommand(as part of the expectsuite of commands), unfortunately this requires a 50mb+ install, but it's the easiest solution:

   sudo apt-get install expect-dev
   unbuffer -p ls --color=auto | cat  
   

   Or if you use the fish shell:

   function faketty
       unbuffer -p $argv
   end
   faketty ls --color=auto | cat 
   

   http://linux.die.net/man/1/unbuffer

1. 使用script+printf，不需要额外的依赖：

   0<&- script -qefc "ls --color=auto" /dev/null | cat
   

   或者做一个bash函数faketty来封装它：

   faketty () {
       script -qfce "$(printf "%q " "$@")"
   }
   faketty ls --color=auto | cat  
   

   或者在鱼壳中：

   function faketty
       script -qefc "(printf "%q " "$argv")"
   end
   faketty ls --color=auto | cat 
   

   （归功于此答案）

   http://linux.die.net/man/1/script

2. 使用unbuffer命令（作为expect命令套件的一部分），不幸的是这需要 50mb+ 的安装，但它是最简单的解决方案：

   sudo apt-get install expect-dev
   unbuffer -p ls --color=auto | cat  
   

   或者，如果您使用鱼壳：

   function faketty
       unbuffer -p $argv
   end
   faketty ls --color=auto | cat 
   

   http://linux.die.net/man/1/unbuffer

This is a great article on how TTYs work and what Pseudo-TTYs (PTYs) are, it's worth taking a look at if you want to understand how the linux shell works with file descriptors to pass around input, output, and signals. http://www.linusakesson.net/programming/tty/index.php

这是一篇关于 TTY 如何工作以及什么是伪 TTY (PTY) 的精彩文章，如果您想了解 linux shell 如何使用文件描述符来传递输入、输出和信号，那么值得一看。http://www.linusakesson.net/programming/tty/index.php