source: nutchez-0.2/src/test/add_hosts @ 163

#!/bin/bash
# Program:
#   Add nutch_nodes to /etc/hosts (for nutchez management interface).
#   $1=/home/nutchuser/nutch_nodes
#   $2=/etc/hosts
# Author: 
#   Waue, Shunfa, Rock {waue, shunfa, rock}@nchc.org.tw
# Version:
#    1.0
# History:
#   2010/06/07  Rock    First release (1.0)

IPs=$(cat $1 | awk '{print $1}')

for ip_addr in $(echo $IPs)
do
    jude=0
    cat $2 | grep ${ip_addr} || jude=1

    if [ $jude == 0 ]; then
# 若有的話，直接取代    
    change_line=$(cat -n $2 | grep ${ip_addr} | awk '{print $1}')
    hostname=$(cat $1 | grep $ip_addr | awk '{print $2}')
    sed -i "${change_line}c $ip_addr   $hostname" $2
    else
# 若沒有，直接新增
    hostname=$(cat $1 | grep $ip_addr | awk '{print $2}')
    sed -i "\$a $ip_addr   $hostname" $2 
    fi
done