Linux bash 检查 mysql 连接
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bash check mysql connect
提问by Erwan
I'm writing a bash script to do some operations against a database on my debian squeeze Server.
我正在编写一个 bash 脚本来对我的 debian 挤压服务器上的数据库执行一些操作。
I have noticed that if I enter a wrong password for root, the prompt will be closed and I won't be asked to try again... that's not very convenient!
我注意到如果我输入了错误的root密码，提示将被关闭，并且不会要求我重试......这不是很方便！
So I was trying to create a loop that attempts to connect to MYSQL and save the password for later if successful.
所以我试图创建一个循环，尝试连接到 MYSQL 并在成功时保存密码以备后用。
I tried this, but it doesn't work. Instead, I receive this error:
我试过这个，但它不起作用。相反，我收到此错误：
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
错误 1045 (28000): 用户 'root'@'localhost' 访问被拒绝（使用密码：YES）
read -s -p "Enter MYSQL root password: " mysqlRootPassword
while [[ -n `mysql -u root -p$mysqlRootPassword` ]]; do
read -p "Can't connect, please retry: " mysqlRootPassword
done
I am not very experienced in bash scripting, any help would be awesome!
我在 bash 脚本方面不是很有经验，任何帮助都会很棒！
采纳答案by shellter
I don't think you need the [[ -n backtic ... ]];test nested like that. Try:
我认为您不需要[[ -n backtic ... ]];像那样嵌套测试。尝试：
read -s -p "Enter MYSQL root password: " mysqlRootPassword
while ! mysql -u root -p$mysqlRootPassword -e ";" ; do
read -s -p "Can't connect, please retry: " mysqlRootPassword
done
whileevaluates any command group upto a closing ; doand checks the return code of last command executed to determine if the loop should be executed. Because you are looking for a failure, you have to precede the test with a logical NOT (!) OR you can use the syntactic equivalent, i.e.
while评估任何命令组直到关闭; do并检查最后执行的命令的返回代码以确定是否应该执行循环。因为您正在寻找失败，所以您必须在测试之前使用逻辑 NOT ( !) 或者您可以使用等效的语法，即
until mysql -u root -p$mysqlRootPassword -e ";" ; do
read -s -p "Can't connect, please retry: " mysqlRootPassword
done
which you can think of as 'until mysql works correctly, keep trying to get the right password'.
您可以将其视为“直到 mysql 正常工作，请继续尝试获取正确的密码”。
Unfortunately, I don't have access to a mysql installation, so this is untested.
不幸的是，我无权访问 mysql 安装，所以这是未经测试的。
I hope this helps.
我希望这有帮助。
