Bash：服务器出现故障时关闭MySQL连接

Question

I have a simple script to connect to a extern MySQL server.

#!/bin/bash
server=1.2.3.1
port=3306
user=root
pass=root
db=radius

output=$(mysql -N -h $server -u $user -p$pass $db -e  "select * from table)
echo "$output"

The problem is when the mysql service fails on server 1.2.3.1, because the script gets stucked waiting for answer a long time!

How can I wait only for 1 second and if server doesn't respond, the script kills the process? Or how can I check if the service is up on the remote server before?

Regards.

Answer 1

I didn't test this out but I suppose you could set a timer and then test whether your result has a value.

#!/bin/bash
server=1.2.3.1
port=3306
user=root
pass=root
db=radius

output=$(mysql -N -h $server -u $user -p$pass $db -e  "select * from table)
sleep 1
if ! [[ $output ]]
   mysql exit
fi
echo "$output"