企业Shell面试题10:开发MySQL启动脚本
说明
MySQL启动命令为:
/bin/sh mysqld_safe --pid-file=$mysqld_pid_file_path 2>&1 > /dev/null &
停止命令为:
mysqld_pid=`cat "$mysqld_pid_file_path"`
if (kill -0 $mysqld_pid 2>/dev/null)
then
kill $mysqld_pid
sleep 2
fi
请完成MySQL启动脚本的编写
要求:用函数,case语句、if语句等实现。
解答:
[[email protected] scripts]# cat /etc/init.d/oldgirl
#!/bin/bash
# chkconfig: 2345 64 36
# description: MySQL startup
#Author:oldboy
#Blog:http://oldboy.blog.51cto.com
#Time:2017-07-07 09:24:34
#Name:mysqld.sh
#Version:V1.0
#Description:This is a test script.
[ -f /etc/init.d/functions ] && source /etc/init.d/functions
Port=3306
User="root"
Bindir="/application/mysql/bin"
Datadir="/application/mysql/data"
mysqld_pid_file_path="/application/mysql/`hostname`.pid"
PATH="/sbin:/usr/sbin:/bin:/usr/bin:$basedir/bin"
export PATH
return_value=0
# Lock directory.
lockdir=‘/var/lock/subsys‘
lock_file_path="$lockdir/mysql"
log_success_msg(){
echo " SUCCESS! [email protected]"
}
log_failure_msg(){
echo " ERROR! [email protected]"
}
case "$1" in
start)
# Start daemon
echo "Starting MySQL"
if test -x $Bindir/mysqld_safe
then
$Bindir/mysqld_safe --datadir="$Datadir" --pid-file="$mysqld_pid_file_path" >/dev/null &
return_value=$?
sleep 2
# Make lock for CentOS
if test -w "$lockdir"
then
touch "$lock_file_path"
fi
exit $return_value
else
log_failure_msg "Couldn‘t find MySQL server ($bindir/mysqld_safe)"
fi
;;
stop)
if test -s "$mysqld_pid_file_path"
then
mysqld_pid=`cat "$mysqld_pid_file_path"`
if (kill -0 $mysqld_pid 2>/dev/null)
then
echo "Shutting down MySQL"
kill $mysqld_pid
return_value=$?
sleep 2
else
log_failure_msg "MySQL server process #$mysqld_pid is not running!"
rm -f "$mysqld_pid_file_path"
fi
# Delete lock for CentOS
if test -f "$lock_file_path"
then
rm -f "$lock_file_path"
fi
exit $return_value
else
log_failure_msg "MySQL server PID file could not be found!"
fi
;;
restart)
if $0 stop; then
$0 start
else
log_failure_msg "Failed to stop running server, so refusing to try to start."
exit 1
fi
;;
*)
echo "Usage: $0 {start|stop|restart}"
exit 1
;;
esac
exit $return_value
函数版:
#!/bin/bash
# chkconfig: 2345 64 36
# description: MySQL startup
#Author:oldboy
#Blog:http://oldboy.blog.51cto.com
#Time:2017-07-07 09:24:34
#Name:mysqld.sh
#Version:V1.0
#Description:This is a test script.
[ -f /etc/init.d/functions ] && source /etc/init.d/functions
port=3306
user="root"
bindir="/application/mysql/bin"
datadir="/application/mysql/data"
mysqld_pid_file_path="/application/mysql/`hostname`.pid"
PATH="/sbin:/usr/sbin:/bin:/usr/bin:$basedir/bin"
export PATH
return_value=0
# Lock directory.
lockdir=‘/var/lock/subsys‘
lock_file_path="$lockdir/mysql"
log_success_msg(){
echo " SUCCESS! [email protected]"
}
log_failure_msg(){
echo " ERROR! [email protected]"
}
start(){
# Start daemon
echo "Starting MySQL"
if test -x $bindir/mysqld_safe
then
$bindir/mysqld_safe --datadir="$datadir" --pid-file="$mysqld_pid_file_path" >/dev/null &
return_value=$?
sleep 2
# Make lock for CentOS
if test -w "$lockdir"
then
touch "$lock_file_path"
fi
exit $return_value
else
log_failure_msg "Couldn‘t find MySQL server ($bindir/mysqld_safe)"
fi
}
stop(){
if test -s "$mysqld_pid_file_path"
then
mysqld_pid=`cat "$mysqld_pid_file_path"`
if (kill -0 $mysqld_pid 2>/dev/null)
then
echo "Shutting down MySQL"
kill $mysqld_pid
return_value=$?
sleep 2
else
log_failure_msg "MySQL server process #$mysqld_pid is not running!"
rm -f "$mysqld_pid_file_path"
fi
# Delete lock for CentOS
if test -f "$lock_file_path"
then
rm -f "$lock_file_path"
fi
exit $return_value
else
log_failure_msg "MySQL server PID file could not be found!"
fi
}
case "$1" in
start)
start
;;
stop)
stop
;;
restart)
if $0 stop; then
$0 start
else
log_failure_msg "Failed to stop running server, so refusing to try to start."
exit 1
fi
;;
*)
echo "Usage: $0 {start|stop|restart}"
exit 1
;;
esac
exit $return_value