string - 为什么 "Here Strings"被称为 "Here Strings"？

Question

这个名字背后的原因是什么？
SS64在 PowerShell 中解释此处的字符串如下:

A here string is a single-quoted or double-quoted string which can span multiple lines.Expressions in single-quoted strings are not evaluated.

All the lines in a here-string are interpreted as strings, even though they are not enclosed in quotation marks.

$myHereString = @'
some text with "quotes" and variable names $printthis 
some more text 
'@ 

Answer 1

它们在 PowerShell 中有这个名称，因为它是从 Unix 风格的 shell 中借来的，就像 PowerShell 中的许多其他元素和概念一样:
From Wikipedia :

Here documents originate in the Unix shell, and are found in sh, csh, ksh, bash and zsh, among others.

至于为什么最初使用这个名字，文章并没有严格涵盖词源，而是基于这样的描述:

In computing, a here document (here-document, here-text, heredoc, hereis, here-string or here-script) is a file literal or input stream literal: it is a section of a source code file that is treated as if it were a separate file. The term is also used for a form of multiline string literals that use similar syntax, preserving line breaks and other whitespace (including indentation) in the text.

名称的“here”部分指的是包含“here”的文件(如此时)，这似乎合乎逻辑。

为了完整起见，值得注意的是，PowerShell 还直接支持单引号和双引号中的换行符 [string] s，像这样:

$myString = 'some text with "quotes" and variable names $printthis 
some more text'

这里字符串有用的一个更好的例子是当你需要两种类型的引号时:

$myHereString = @'
some text with "quotes" and variable names $printthis 
some more text 
and my grandma's soup
'@ 

如果这只是一个单引号字符串，则 '在 grandma's将需要逃脱。
如果是双引号字符串，则需要转义 " 的实例。你需要逃离 $如果你不想变量扩展。

有趣的是:此处字符串的解释方式之间的差异构成了 this demonstration of writing a bash/powershell/win batch polyglot 的基础(其内容可以在任何这些环境中执行的脚本)。