一般情況下，我們想要進入MySQL命令模式總是需要按如下交互輸入密碼確認，才能進入命令行模式：
zhanhailiang@linux-06bq:~> mysql -u sl -p
Enter password:
其實我們完全可以使用expect編寫腳本，來通來expect與shell交互通信來實現免密碼登錄：
zhanhailiang@linux-06bq:~> cat mysql.sh
#!/usr/local/bin/expect
spawn /usr/local/services/mysql/bin/mysql -u sl -p
expect {
"assword" { send "slr" }
}
interact
其實這段腳本的意思就是說“執行/usr/local/services/mysql/bin/mysql -u sl -p，等待響應，若匹配assword，則發送sl(即MySQL用戶登錄密碼)，回車，模擬用戶手工操作”。
編寫完mysql.sh腳本後，賦予執權限，然後就可以通過執行mysql.sh來免密碼進入MySQL命令行模式。
zhanhailiang@linux-06bq:~> chmod +x mysql.sh
zhanhailiang@linux-06bq:~> ./mysql.sh
spawn /usr/local/services/mysql/bin/mysql -u sl -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 12912
Server version: 5.5.14-log MySQL Community Server (GPL)
Copyright (c) 2000, 2010, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql>
注：expect擁有眾多的參數及豐富的應用場景，有興趣的同學請自行查看man手冊或其它資料。
