How to convert php ip to int

php ip to int method: 1. Create a PHP sample file; 2. Define an ip address; 3. Convert the ip address to an integer through the ip2long function in PHP.

The operating environment of this article: Windows7 system, PHP7.1 version, Dell G3 computer

How to convert php ip to int?

Detailed explanation of conversion between IP addresses and integer numbers in PHP

This article introduces the use of PHP functions ip2long and long2ip, as well as their BUG introduction, and finally I will give you the two algorithms I wrote. Friends who need it can refer to

Converting IP to integer storage is a major trend in database optimization. Many people are still using string type storage when storing IP. Characters String indexes consume more resources than integer indexes, especially when the amount of data in the table is large, and when you want to query the data of a certain IP segment. The IP mentioned today refers to IP4, and IP6 is not within the scope of this article.

System functions ip2long and long2ip
There is a built-in function ip2long in PHP that can convert the ip address to an integer.

The code is as follows:

$ip = '210.110.11.49';
echo ip2long($ip);

Output:

-764540111

The output integer type has a negative sign because the result we get is a signed integer type, and the maximum value of the signed integer type is 2147483647. To convert the result to unsigned type, you can write like this

3530427185

Use long2ip to convert the integer type back to the IP address

$ip = '210.110.11.49';$ip_int = ip2long($ip);echo $ip."<br />";echo $ip_int."<br />";echo long2ip($ip_int);

Output:

210.110.011.49
-764540623
210.110.9.49

The conversion results do not match, we try to add a leading 0 before the first number of the ip, and then look at the

$ip = '021.110.11.49';$ip_int = ip2long($ip);echo $ip."<br />";echo $ip_int."<br />";echo long2ip($ip_int);

output:

021.110.11.49
292424497
17.110.11.49

The conversion results are all wrong. The above examples are all caused by adding leading 0, resulting in an error in the conversion result, and the reversal result does not match the original converted IP.

Conversion Principle

There are currently two algorithms:
First, the first section is multiplied by the cube of 256, and the second section is multiplied by The square of 256, the third segment is multiplied by 256, and the final sum is

$ip = '0210.110.11.49'; 
function ipToInt($ip){    $iparr = explode('.',$ip);    $num = 0;    for($i=0;$i<count($iparr);$i++){        $num += intval($iparr[$i]) * pow(256,count($iparr)-($i+1));
    }    return $num;
} 
echo  $ip.'<br />';$ip_int = ipToInt($ip);echo $ip_int.'<br />';echo long2ip($ip_int);

Output:

0210.110.11.49
3530427185
210.110.11.49

Second, through the bitwise operator

$ip = '0210.110.11.49'; 
function ipToInt($ip){    $iparr = explode('.',$ip);    return (intval($iparr[0]<<24))|(intval($iparr[1])<<16)|(intval($iparr[2])<<8)| (intval($iparr[3]));
} 
echo  $ip.'<br />';$ip_int = ipToInt($ip);echo $ip_int.'<br />';echo long2ip($ip_int);

Output:

0210.110.11.49
-764540111
210.110.11.49

Check whether the IP is legal

First, traverse the test yourself

function check_ip($ip){    $iparr = explode('.',$ip);    foreach($iparr as $v){ if($v>255) return false; }    return true;
} 
echo '210.285.11.49,';var_dump(check_ip('210.285.11.49'));echo '<br />';echo '210.205.11.49,';var_dump(check_ip('210.205.11.49'));
[code]

输出：
[code]210.285.11.49,bool(false)210.205.11.49,bool(true)

No. 2. Use ip2long to return

function check_ip($ip){    if(ip2long($ip)) return true;    return false;
} 
echo '210.285.11.49,';var_dump(check_ip('210.285.11.49'));echo '<br />';echo '210.205.11.49,';var_dump(check_ip('210.205.11.49'));

Output:

210.285.11.49,bool(false)210.205.11.49,bool(true)

Postscript

Many people use ip2long to convert the ip writing library to store int type field, however, on different system platforms, the values ​​obtained by the ip2long function are different, so it may cause that the ip obtained by long2ip does not match the original ip when reading data from the database to reverse the ip.
If it is Mysql can be solved using the mysql system functions INET_ATON and INET_NTOA, or using the bigint type, or writing functions yourself.

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