将变量替换为 sed 脚本

Question

运行此代码后

#!/bin/bash
rm -f myfile myfile-individual
echo "Greetings, foobar!" > myfile
MYSTRING="Jack"
cat myfile | sed 's:foobar:$MYSTRING:' > myfile-individual

我们最终得到

Greetings, $MYSTRING!

在我的个人档案中。

输出的（sed/bash）脚本应该是什么

Greetings, Jack!

Answer 1

将单引号更改为双引号。然后放下猫（UUoC）：

sed "s:foobar:$MYSTRING:" myfile > myfile-individual

从 bash 的联机帮助页：

   Enclosing characters in single quotes preserves the  literal  value  of
   each character within the quotes.  A single quote may not occur between
   single quotes, even when preceded by a backslash.

   Enclosing characters in double quotes preserves the  literal  value  of
   all  characters  within the quotes, with the exception of $, `, \, and,
   when history expansion is enabled, !.  The characters $  and  `  retain
   their  special meaning within double quotes.  The backslash retains its
   special meaning only when followed by one of the following  characters:
   $,  `,  ", \, or <newline>.  A double quote may be quoted within double
   quotes by preceding it with a backslash.  If enabled, history expansion
   will  be  performed  unless an !  appearing in double quotes is escaped
   using a backslash.  The backslash preceding the !  is not removed.