Perl脚本检测一个域名是否有效
脚本功能：通过ICMPPing或TCP/SYN探测指定的域名，探测前检测域名是否有效。
file:check.host.pl
#!/usr/bin/perl
usestrict;
useNet::Ping;
useNet::DNS;
useTime::HiResqw();
$|=1;
my$DEFAULT_TIMEOUT=2;
my$PING_TIMEOUT=2;
my$DNS_TIMEOUT=3;
###查询域名是否有效
subqueryDomain{
my$domain=shift();
my$query='';
my$dns=Net::DNS::Resolver->new(
tcp_timeout=>$DNS_TIMEOUT,udp_timeout=>$DNS_TIMEOUT,retry=>1
);
my@nameservers=qw/8.8.8.8114.114.114.114/;
$dns->nameservers(@nameservers);
eval{
$query=$dns->search($domain,'A');
};
if($@or!$query){
my$err=$dns->errorstring;
print"ERR:query$domainfailed:$errn";
returnif($err=~/NXDOMAIN/);
}
return'OK';
}
###returnnothingisFAILED,otherisOK
subpingHost{
my$arg=shift();
return1if(ref$argne'HASH');
my$p;
eval{$p=Net::Ping->new($arg->{'proto'},$DEFAULT_TIMEOUT,0)};
if($@){
warn"ERRtocreateNet::Pingobject:$@n";
return;
}
$p->hires();
my($host,$duration,$hip,$rep,$ret);
###tcp/synping
if($arg->{'proto'}eq"syn"){
$p->{port_num}=$arg->{'port'};
$p->ping($arg->{'host'},$PING_TIMEOUT);
if(($host,$duration,$hip)=$p->ack()){
printf("ACKReplyfrom$arg->{'host'}[%s]time=%.2fmsn",$hip,$duration*1000);
$ret='OK';
}else{
warn"SYNRequestfor$arg->{'host'}timedout.n";
}
}
###icmpping
else{
($rep,$duration,$hip)=$p->ping($arg->{'host'},$PING_TIMEOUT);
if($rep){
printf("EchoReplyfrom$arg->{'host'}[%s]time=%.2fmsn",$hip,$duration*1000);
$ret='OK';
}
else{
warn"PINGRequestfor$arg->{'host'}timedout.n";
}
}
$p->close;
undef($p);
return$ret;
}
my$ARG={proto=>'syn',port=>80};
my$host=$ARGV[0];
my$proto=$ARGV[1];
die"Usage:$0[icmp]n"if(!$host);
$ARG->{'host'}=$host;
$ARG->{'proto'}=$protoif($proto);
my$code;
if(&queryDomain($host)eq'OK'and$code=&pingHost($ARG)){
print"$hostisonline!n";
}
else{
print"$hostisDOWN!n";
}
测试例子：
#./check.host.pl2013.jb51.net ERR:query2013.jb51.netfailed:NXDOMAIN 2013.jb51.netisDOWN! #./check.host.plwww.nhooo.com ACKReplyfromwww.nhooo.com[173.255.214.254]time=307.04ms www.nhooo.comisonline! #./check.host.pljb51.neticmp EchoReplyfromjb51.net[173.255.214.254]time=205.61ms jb51.netisonline! #./check.host.plchinagfw.comicmp PINGRequestforchinagfw.comtimedout. chinagfw.comisDOWN!