shell - 如何在命令中解析字符串中的环境值？

Question

导出 MySQLIP="2.2.2.2"

consul kv put micro/mysql '{"enabled": true, "url":"root:yourpassword@($MySQLIP:3306)"}'

上面的命令运行时如何让$MySQLIP变成2.2.2.2？我知道这与 shell 脚本有关。请帮忙。

Answer 1

Use double quotes to allow variables to be expanded:

consul kv put micro/mysql '{"enabled": true,
    "url":"root:yourpassword@'"$MySQLIP"':3306"}'

Above, we are essentially concatenating three strings, the first and last are single-quoted, and the 2nd is double quoted. You can also write:

consul kv put micro/mysql "{\"enabled\": true,
        \"url\":\"root:yourpassword@$MySQLIP:3306\"}"

if you find it clearer. There a many ways to quote strings in the shell.