Bash 在使用反引号时提示 here-document 中的语法错误

Question

我正在运行以下一段 bash 代码:

cat << END_TEXT
       _             _ 
      | |           | |
  __ _| |__   ___ __| |
 / _` | '_ \ / __/ _` |
| (_| | |_) | (_| (_| |
 \__,_|_.__/ \___\__,_|
END_TEXT

出现错误:

bash: command substitution: line 1: syntax error near unexpected token `|'
bash: command substitution: line 1: ` | '_ \ / __/ _'

Answer 1

无需转义反引号。只需使用引用的 here-doc 字符串作为:

cat <<-'END_TEXT'
        _             _
       | |           | |
   __ _| |__   ___ __| |
  / _` | '_ \ / __/ _` |
 | (_| | |_) | (_| (_| |
  \__,_|_.__/ \___\__,_|
END_TEXT

根据 man bash :

If word is unquoted, all lines of the here-document are subjected to parameter expansion, command substitution, and arithmetic expansion, the character sequence \<newline> is ignored, and \ must be used to quote the characters \, $, and `.