请问这个perl的一个在bash的衬垫的作品？ [英] How does this perl one liner in the bash works?

问题描述

我一直在寻找的，我可以如何根据每个句子的长短排序文件，我对面这个<一个这个片段来了href=\"http://stackoverflow.com/questions/12417403/how-to-sort-the-lines-in-a-file-from-shortest-to-longest\">answer

I was looking on how I could sort a file based on the length of each sentence and I came across this snippet from this answer

perl -ne 'push @a, $_ } { print sort { length $a <=> length $b } @a' input
                      ^ ^  

我测试了它和它的作品，但我没有一个线索是如何工作的！据我所看到的语法是错误的。它有一个开放的右括号和非封闭我标志着右括号。结果
我真的有麻烦搞清楚如何在bash结果像这样运行perl的命令
可能有人请解释这个片段？

I tested it and it works but I don't have a clue how this works! As far as I can see the syntax is wrong. It has an open right bracket and a non closed right bracket which I have marked.
I am really having trouble figuring out how to run perl commands like this in bash
Could some one please explain this snippet?

推荐答案

} {就是所谓的蝴蝶或的 爱斯基摩人的问候 阿比盖尔发现，在1997年。

}{ is so called butterfly or Eskimo greeting Discovered by Abigail, in 1997.

基本上它关闭由 -n 实行，而循环开关，接下来} { while循环后的程序段执行。

Basically it closes while loop imposed by -n switch, and what follows }{ is block executed after while loop.

这就是Perl解析这一行，

This is how perl parses this line,

perl -MO=Deparse -ne 'push @a, $_ } { print sort { length $a <=> length $b } @a' input

---

LINE: while (defined($_ = <ARGV>)) {
    push @a, $_;
}{ # <==here it is

    print((sort {length $a <=> length $b;} @a));
}

一个比较常见的方法就是使用的 END {} 块而不是} {运营商：

A more common way would be using END{} block instead of }{ operator:

perl -ne '
  push @a, $_ 
  END { 
    print sort { length $a <=> length $b } @a
  }
' input

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