Question

我正在尝试确定我在cisco路由器上放置的命令是否只有以下输出中的邻居条目..

我有以下正则表达式..如果搜索到达结尾但未找到第二个匹配项，如何使搜索失败？

if (! $document =~/(Device\sID)(.*?)(Device\sID)/s){        
    print("Theres no double entries\n");
} else { 
    print ("double!\n");
}

Device ID: NAME1
Entry address(es): 
  IP address: IP.IP.IP.IP
Plautform: cisco WS-C3850-48T,  Capabilities: Switch IGMP 
Interface: GigabitEthernet1/x,  Port ID (outgoing port): GigabitEthernetx/x/x
Holdtime : 123 sec

Version :
Cisco IOS Software, IOS-XE Software, Catalyst L3 Switch Software (CAT3K_CAA-UNIVERSALK9-M), Version 03.02.03.SE RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2013 by Cisco Systems, Inc.
Compiled Mon 23-Sep-13 18:24 by prod_rel_team

advertisement version: 2
VTP Management Domain: 'NAME1'
Native VLAN: 1
Duplex: full
Management address(es): 
  IP address: IP.IP.IP.IP

此致彼得

Answer 1

!~是正则表达式不匹配的运算符。

$document !~ /(Device\sID)(.*?)(Device\sID)/s

Answer 2

您遇到运营商优先问题。 !的优先级高于=~，因此您的表达式为：

 if ( ! $document =~ /(Device\sID)(.*?)(Device\sID)/s ) {

与：

相同

 if ( (! $document) =~ /(Device\sID)(.*?)(Device\sID)/s ) {

但你想：

 if ( ! ($document =~ /(Device\sID)(.*?)(Device\sID)/s) ) {

与以下内容相同：

 if ( $document !~ /(Device\sID)(.*?)(Device\sID)/s ) {

Perl Regex与重复模式不匹配

2 个答案: