here document word with quotation mark or not

最新推荐文章于 2025-08-11 21:40:56 发布

nyhenry

最新推荐文章于 2025-08-11 21:40:56 发布

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本文链接：https://blog.youkuaiyun.com/nyhenry/article/details/2027081

本文详细介绍了HereDocuments的概念及其在shell脚本中的使用方法。HereDocuments允许将一系列文本输入作为命令的标准输入，直到遇到指定的结束标记。本文解释了不同类型的HereDocuments，并提供了如何正确设置和使用它们的指导。

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Here Documents

This type of redirection instructs the shell to read input from the current source until a line containing only word (with no trailing blanks) is seen. All of the lines read up to that point are then used as the standard input for a command.

The format of here-documents is as follows:

<<[-]word
        here-document
delimiter

No parameter expansion, command substitution, arithmetic expansion, or filename expansion is performed on word. If any characters in word are quoted, the delimiter is the result of quote removal on word, and the lines in the here-document are not expanded. If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion. In the latter case, the character sequence /newline is ignored, and `/' must be used to quote the characters `/', `$', and ``'.