[系统运维]Shell范例4：nginx启动管理脚本

#!/bin/bash
# nginx service manage script

#variables
proc=nginx
nginx_install_doc=/usr/local/nginx
nginxd=$nginx_install_doc/sbin/nginx
pid_file=$nginx_install_doc/logs/nginx.pid

# Source function library.
if [ -f /etc/init.d/functions ]; then
	. /etc/init.d/functions
else
	echo "not found file /etc/init.d/functions"
	exit
fi

if [ -f $pid_file ];then
	nginx_process_id=`cat $pid_file`
	nginx_process_num=`ps aux | grep $nginx_process_id | grep -v "grep" | wc -l`
fi
 
#function
start () {
#如果nginx没有启动直接启动，否则报错已经启动
if[ -f $pid_file ] && [ $nginx_process_num -ge 1 ];then
	echo "nginx running..."
else 
	if [ -f $pid_file ] && [ $nginx_process_num -lt 1 ];then
		rm -f $pid_file
		action "nginx start" $nginxd
    fi
    action "nginx start" $nginxd
fi
}

stop () {
if [ -f $pid_file ] && [ $nginx_process_num -ge 1 ];then
	action "nginx stop" killall -s QUIT $proc
	rm -f $pid_file
else
	action "nginx stop" killall -s QUIT $proc 2>/dev/null
fi
}

restart () {
	stop
	sleep 1
	start
}

reload () {
if [ -f $pid_file ]&&[ $nginx_process_num -ge 1 ];then
	action "nginx reload" killall -s HUP $proc
else
	action "nginx reload" killall -s HUP $proc 2>/dev/null
fi
}

status () {
if [ -f $pid_file ]&&[ $nginx_process_num -ge 1 ];then
	echo "nginx running..."
else
	echo "nginx stop"
fi
}

# callable
case $1 in
start) start;;
stop) stop;;
restart) restart;;
reload) reload;;
status) status;;
*) echo "USAGE: $0 start|stop|restart|reload|status";;
esac