为什么使用“gethostbyaddr”将IP地址转换为主机名但不起作用？ [关闭]

Question

I try to convert IP Address to Hostname by used "gethostbyaddr" but don't work. I use file.text that is log file to analyze which page that user used a lot or less. So I try to cut sentence that use array. This is my code.

$file=fopen("log.txt","r");             

while (!feof($file)) {
    $buffer = fgets($file, 4096);                    

    $text= explode(" ",$buffer,10);



    $text_2=@$text[1];  
    $ip=substr($text_2,1,11);       
    $ip2=gethostbyaddr($ip);

    echo"INSERT INTO `log` VALUES ('$ip2');"."<br>";        //Show results

    //echo"<br>";           //New line
}

fclose($file);                              

Thanks

Answer 1

that means gethostbyaddr failed.

not because your input, find the explanation in php documentation

http://php.net/manual/en/function.gethostbyaddr.php

"Returns the host name on success, the unmodified ip_address on failure, or FALSE on malformed input."