防止在反引号中包含的表达式在heredocs中求值

问题描述

我有这样的文字:

foo bar
`which which`

如果我使用heredoc进行此操作，则会得到一个空白文件:

If I do this using heredoc, I get a blank file:

➜  ~  echo <<EOT > out
heredoc> foo bar
heredoc> `which which`
heredoc> EOT
➜  ~  cat out

➜  ~  

我该怎么做?

哦，对不起，我打算做cat.问题是它将它写入文件:which: shell built-in command，即求值反引号.有没有做任何评估的方法吗?

Oh sorry, I meant to do cat. Problem is that it writes this to the file: which: shell built-in command, ie, evaluations backticks. Any way to do this without evaluating?

有了cat，我得到了

➜  ~  cat <<EOT > out
heredoc> foo bar
heredoc> `which which`
heredoc> EOT
➜  ~  cat out
foo bar
which: shell built-in command
➜  ~  

我不希望对which which进行评估.

推荐答案

引用标签以防止反引号得到评估.

Quote the label to prevent the backticks from being evaluated.

$ cat << "EOT" > out
foo bar
`which which`
EOT

$ cat out
foo bar
`which which`

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