变量不在单引号内展开.使用双引号重写:

Variables are not expanded within single-quotes. Rewrite using double-quotes:

curl -X POST -H 'Content-type: application/json' --data "{"text": "${message}"}"

请记住，双引号内的双引号必须被转义.

Just remember that double-quotes within double-quotes have to be escaped.

另一种变化可能是:

curl -X POST -H 'Content-type: application/json' --data '{"text": "'"${message}"'"}'

这个从单引号中跳出来，将 ${message} 括在双引号内以防止分词，然后以另一个单引号字符串结束.即:

This one breaks out of the single quotes, encloses ${message} within double-quotes to prevent word splitting, and then finishes with another single-quoted string. That is:

... '{"text": "'"${message}"'"}'
    ^^^^^^^^^^^^
    single-quoted string


... '{"text": "'"${message}"'"}'
                ^^^^^^^^^^^^
                double-quoted string


... '{"text": "'"${message}"'"}'
                            ^^^^
                            single-quoted string