嵌入式 busybox 使用 cronjob

check_3g_network.sh

#!/bin/sh
# file: /root/check_3g_network.sh


LOGGER_TAG="3g_network_check"

ping -c 5 www.baidu.com > /dev/null

if [ $? -eq 0 ]; then
    logger -t LOGGER_TAG "3g network is connection."
else
    logger -t LOGGER_TAG "3g network is disconnection."
    logger -t LOGGER_TAG "trying kill exist connection process."
    kill `ps | pgrep "[p]ppd"`
    logger -t LOGGER_TAG "kill exist connection process successfully."
    logger -t LOGGER_TAG "try reconnect 3g network"
    pppd call wcdma-usb2 &> /dev/null
fi

rcS

# file: /etc/init.d/rcS

# connection wcdma 3g network on boot
pppd call wcdma-usb2 


# 创建 crontabs 工作目录
mkdir -p /var/spool/cron/crontabs

# 复制 /etc/crontabs 的自动任务到 crontabs 工作目录
cp -p /etc/crontabs/root /var/spool/cron/crontabs

# 给 crontabs 工作目录加权限
chmod 777 /var/spool/cron/crontabs/root

# 启动 crond 守护进程
crond

# 卖个萌
echo "cp cron config file to /var/spool/cron/crontabs"

root

# file: /etc/crontabs/root

# m minute
# h hour
# dom day of month
# mon mouth
# dow day of week
# m    h    dom    mon    dow
*  *  *  *  *  /root/check_3g_network.sh