监控网站是否异常的shell脚本

#!/bin/bash 
# site: www.jquerycn.cn
SITES=("http://web01.example.com" "http://web02.example.com") # 要监控的网站 
NOTICE_EMAIL='me@example.com'                                 # 管理员电邮 
MAXLOADTIME=10                                                # 访问超时时间设置 
REMARKFILE='/tmp/monitor_load.remark'                         # 记录时否发送过通知电邮，如发送过则一小时内不再发送 
ISSEND=0                                                      # 是否有发送电邮 
EXPIRE=3600                                                   # 每次发送电邮的间隔秒数 
NOW=$(date +%s) 
 
if [ -f "$REMARKFILE" ] && [ -s "$REMARKFILE" ]; then 
    REMARK=$(cat $REMARKFILE) 
     
    # 删除过期的电邮发送时间记录文件 
    if [ $(( $NOW - $REMARK )) -gt "$EXPIRE" ]; then 
        rm -f ${REMARKFILE} 
        REMARK="" 
    fi 
else 
    REMARK="" 
fi 
 
# 循环判断每个site 
for site in ${SITES[*]}; do 
 
    printf "start to load ${site}\n" 
    site_load_time=$(curl -o /dev/null -s -w "time_connect: %{time_connect}\ntime_starttransfer: %{time_starttransfer}\ntime_total: %{time_total}" "${site}") 
    site_access=$(curl -o /dev/null -s -w %{http_code} "${site}") 
    time_total=${site_load_time##*:} 
 
    printf "$(date '+%Y-%m-%d %H:%M:%S')\n" 
    printf "site load time\n${site_load_time}\n" 
    printf "site access:${site_access}\n\n" 
 
    # not send 
    if [ "$REMARK" = "" ]; then 
        # check access 
        if [ "$time_total" = "0.000" ] || [ "$site_access" != "200" ]; then 
            echo "Subject: ${site} can access $(date +%Y-%m-%d' '%H:%M:%S)" | sendmail ${NOTICE_EMAIL} 
            ISSEND=1 
        else 
            # check load time 
            if [ "${time_total%%.*}" -ge ${MAXLOADTIME} ]; then 
                echo "Subject: ${site} load time total:${time_total} $(date +%Y-%m-%d' '%H:%M:%S)" | sendmail ${NOTICE_EMAIL} 
                ISSEND=1 
            fi 
        fi 
    fi 
 
done 
 
# 发送电邮后记录发送时间 
if [ "$ISSEND" = "1" ]; then 
    echo "$(date +%s)" > $REMARKFILE 
fi 
exit 0