BASH Shell 编程 经典教程 《高级SHELL脚本编程》中文版

				#!/bin/bash				# ex18.sh								# 是否'whois domain-name'能够找到如下3个服务之一: 				#                    ripe.net, cw.net, radb.net								# 把这个脚本重命名为'wh', 然后放到/usr/local/bin目录下.								# 需要符号链接:				# ln -s /usr/local/bin/wh /usr/local/bin/wh-ripe				# ln -s /usr/local/bin/wh /usr/local/bin/wh-cw				# ln -s /usr/local/bin/wh /usr/local/bin/wh-radb								E_NOARGS=65												if [ -z "$1" ]				then				  echo "Usage: `basename $0` [domain-name]"				  exit $E_NOARGS				fi								# 检查脚本名字, 然后调用合适的服务.				case `basename $0` in    # Or:    case ${0##*/} in				    "wh"     ) whois $1@whois.ripe.net;;				    "wh-ripe") whois $1@whois.ripe.net;;				    "wh-radb") whois $1@whois.radb.net;;				    "wh-cw"  ) whois $1@whois.cw.net;;				    *        ) echo "Usage: `basename $0` [domain-name]";;				esac 								exit $?