如何判断一个IP地址是否属于某个网段

时间：2008-03-20 来源：ptg0808

有如下两个文本文件（IPlist.txt和IPsegment.txt)，IPlist.txt包含有一些网站的IP地址，如何编程判断这些IP地址是否属于IPsegment.txt所列的网段中。
不匹配的结果输出到文本文件matchinglist.txt中。

三个文件的格式如下：
IPlist.txt
www.abc.com www.yahoo.com 66.94.230.51
www.cdb.com www.baidu.com 202.108.250.249
www.cdf.com www.sina.com.cn 61.135.152.77
www.afc.com www.sohu.com 61.135.150.75

IPsegment.txt
219.111.192.0/18
68.132.0.0/17
61.135.0.0/16
192.162.0.0/16
152.172.0.0/16
34.132.0.0/14
97.208.0.0/13

matchinglist.txt
www.cdf.com www.sina.com.cn 61.135.152.77
www.afc.com www.sohu.com 61.135.150.75 ========================================================= 已经有的列子: 有如下两个文本文件（IPlist.txt和IPsegment.txt)，IPlist.txt包含有一些网站的IP地址，如何编程判断这些IP地址是否属于IPsegment.txt所列的网段中。
匹配的结果输出到文本文件matchinglist.txt中。

三个文件的格式如下：
IPlist.txt
www.yahoo.com,66.94.230.51
www.baidu.com,202.108.250.249
www.sina.com.cn,61.135.152.77
www.sohu.com,61.135.150.75

IPsegment.txt
219.111.192.0/18
68.132.0.0/17
61.135.0.0/16
192.162.0.0/16
152.172.0.0/16
34.132.0.0/14
97.208.0.0/13

matchinglist.txt
www.sina.com.cn,61.135.152.77
www.sohu.com,61.135.150.75 apile兄写的针对下面的要求 #!/usr/bin/perl
open(FF,"IPlist.txt");
my %name;
my %net;
while(<FF>){
  s/[\015\012]//;
  my ($t1,$t2) = split(/,/);
  $name{$t1} = $t2;
}
close(FF);
open(FF,"IPsegment.txt");

while(<FF>){
  s/[\015\012]//;
  my ($t1,$t2) = split(/\//);
  $net{$t1} = $t2;
}
close(FF);
for $net (keys %net){
  my $netmask = $net{$net};
  my $net_bits1 = &bitsIP($net,$netmask);
  for $name (keys %name){
   my $net_bits2 = &bitsIP($name{$name},$netmask);
   if($net_bits2 eq $net_bits1){
      print "$name,".$name{$name}."\n";
      next;
   }
  }
}

#--取得bits of net address
sub bitsIP(){
  my($ip,$netmask)= @_;
  my @ip =split(/,/,$ip);
  my $b = unpack("B32", pack("C4",$ip[0],$ip[1],$ip[2],$ip[3]));
  my $substr= substr($b,0,$netmask);
  return $substr;
}