Hacky Simple IPPlan to {php}IPAM script

migrate-ipaddresses-from-ipplan-to-phpipam.php

<?php

/*
 * Quick and dirty script to import IPv4 addresses from an IPPlan export (converted to CSV)
 * into {php}IPAM to suit a particular use case:
 *
 * - IPv4 only
 * - no consideration of VLANs, VRFs
 * - subnets already exist (we could import the IPPlan export directly into {php}IPAM
 *
 * Released in the hope it can be hacked to help someone else. It's very hacky as is!
 *
 * Barry O'Donovan <barry (at) islandbridgenetworks (dot) ie>
 * MIT License
 */

$db = mysqli_connect('localhost','phpipam','password','phpipam')
    or die( "Could not connect to MySQL" );

$fp = fopen('ipplan-exported-addresses.csv','r')
        or die("Could not open CSV");

while( ( $data = fgetcsv($fp,4096,',') ) !== false ) {
    $ip   = $data[0] ?? null;
    if( !$ip ) continue;
    
    $desc = trim( trim( ( $data[1] ?? "" ) ) . ' [' . trim( ( $data[2] ?? "" ) ) . ']' . ' (' . trim( ( $data[3] ?? "" ) ) . ')' );
    if( $desc == '[] ()' ) continue;

    $dns   = $data[4] ?? "";
    
    $note = "";
    
    foreach( [5,6,7,8] as $i) {
        if( trim( $data[$i] ?? "" ) !== "" )
            $note .= trim( $data[$i] ) . "\n";
    }


    // have data, find address / subnet and add
    
    // does address exist
    $r = mysqli_query($db, "SELECT * FROM ipaddresses WHERE ip_addr = INET_ATON('{$ip}')");

    if( mysqli_num_rows($r) ) {
        // address exists, just update:
        $a = mysqli_fetch_row( $r );
        
        mysqli_query( $db, sprintf( "UPDATE ipaddresses SET description = '%s', dns_name = '%s', note = '%s' WHERE id = %d",
            mysqli_real_escape_string($db,$desc), mysqli_real_escape_string($db,$dns),mysqli_real_escape_string($db,$note),$a[0]
        ));
        echo "UPDATED $ip\n";
        continue;
    }

    // address does not exist - first find subnet (smallest containing subnet)
    $r = mysqli_query($db, "SELECT * FROM subnets WHERE subnet <= INET_ATON('{$ip}') AND (subnet+(POWER(2,32-mask))) > INET_ATON('{$ip}') ORDER BY mask DESC LIMIT 1");
    if( mysqli_num_rows($r) ) {
        $a = mysqli_fetch_row( $r );

        if( !mysqli_query( $db, sprintf( "INSERT INTO ipaddresses
                        ( subnetId, ip_addr, description, dns_name, note, editDate )
                        VALUES ( %d, %d, '%s', '%s', '%s', NOW() )",
                        $a[0], ip2long($ip), mysqli_real_escape_string($db,$desc), mysqli_real_escape_string($db,$dns),mysqli_real_escape_string($db,$note)
                    ))
            ) {
                echo "ERROR $ip: " . mysqli_error($db) . "\n";
            }

        echo "INSERTED $ip\n";
        continue;
    }
    
    echo "ERROR $ip No Subnet\n";

}



fclose($fp);
mysqli_close($db);

I don't really understand PHP. Any instrucitions on how about I can run this