bash shell 检查网络

#!/bin/bash
# Simple SHELL script for Linux and UNIX system monitoring with
# ping command
# -------------------------------------------------------------------------
# Copyright (c) 2006 nixCraft project <http://www.cyberciti.biz/fb/>
# This script is licensed under GNU GPL version 2.0 or above
# -------------------------------------------------------------------------
# This script is part of nixCraft shell script collection (NSSC)
# Visit http://bash.cyberciti.biz/ for more information.
# -------------------------------------------------------------------------
# Setup email ID below
# See URL for more info:
# http://www.cyberciti.biz/tips/simple-linux-and-unix-system-monitoring-with-ping-command-and-scripts.html
# -------------------------------------------------------------------------
 
# add ip / hostname separated by white space
HOSTS="cyberciti.biz theos.in router"
 
# no ping request
COUNT=1
 
# email report when
SUBJECT="Ping failed"
EMAILID="[e-mail]"
for myHost in $HOSTS
do
  count=$(ping -c $COUNT $myHost | grep 'received' | awk -F',' '{ print $2 }' | awk '{ print $1 }')
  if [ $count -eq 0 ]; then
    # 100% failed
    echo "Host : $myHost is down (ping failed) at $(date)" | mail -s "$SUBJECT" $EMAILID
  fi
done

http://bash.cyberciti.biz/monitoring/monitor-windows-linux-server-with-ping-script/