PHP - Euclidean Distance Algorithm In Php

I have a page that gets the closest stores to a latitude and longitude. I want to have a MySQL table like this:

location_id:::::items

showing how many items are at each store and then show 'spit' them in the following format with the lowest number of items first:

location_id, distance to location_id, items.

here is the code I am using to show location_id by distance


Code: [Select]
<?php

include "connectionfile.php";

$lat = $_GET["lat"];
$lng = $_GET["lng"];


$sql = mysql_query("SELECT id, ( 6371 * acos( cos( radians($lat) ) * cos( radians( lat ) )
  * cos( radians( lng ) - radians($lng) ) + sin( radians($lat) ) 
  * sin( radians( lat ) ) ) ) AS distance
FROM locations
HAVING distance < 250
ORDER BY distance LIMIT 0 , 60;
");

WHILE($lstlocations = mysql_fetch_array($sql)) {
$location_id[$count]=$lstlocations['id'];
$distance=$lstlocations['distance'];

echo "id = " . $location_id[$count] . "  Distance = " . $distance. "<br>";
$count = $count + 1;
}

?>

What would be the best way to achieve this?

Hi,

I have been using the following function on my server and it works fine but when I try and use it on a different server it wont seem to work. Any ideas on why it wont work on the new server and any ideas on how I can do some error checking to figure out why ?

Thanks in advance,

Scott

Code: [Select]
<?php
function get_driving_information($start, $finish, $raw = false)
 {
     # Convert any lon / lat coordingates
     if(preg_match('@-?[0-9]+\.?[0-9]*\s*,\s*-?[0-9]+\.?[0-9]@', $start))
     {
         $url = 'http://maps.google.co.uk/m/local?q='.urlencode($start);
         if($data = file_get_contents($url))
         {
             if(preg_match('@<div class="cpfxql"><a href="[^"]*defaultloc=(.*?)&amp;ll=@smi', $data, $found))
             {
                 $start = trim(urldecode($found[1]));
             }
             else
             {
                 throw new Exception('Start lon / lat coord conversion failed');
             }
         }
         else
         {
             throw new Exception('Start lon / lat coord conversion failed');
         }
     }
 
    if(preg_match('@-?[0-9]+\.?[0-9]*\s*,\s*-?[0-9]+\.?[0-9]@', $finish))
     {
         $url = 'http://maps.google.co.uk/m/local?q='.urlencode($finish);
         if($data = file_get_contents($url))
         {
             if(preg_match('@<div class="cpfxql"><a href="[^"]*defaultloc=(.*?)&amp;ll=@smi', $data, $found))
             {
                 $finish = trim(urldecode($found[1]));
             }
             else
             {
                 throw new Exception('Finish lon / lat coord conversion failed');
             }
         }
         else
         {
             throw new Exception('Finish lon / lat coord conversion failed');
         }
     }
 
    if(strcmp($start, $finish) == 0)
     {
         $time = 0;
         if($raw)
         {
             $time .= ' seconds';
         }
 
        return array('distance' => 0, 'time' => $time);
     }
 
    $start  = urlencode($start);
     $finish = urlencode($finish);
 
    $distance   = 'unknown';
     $time       = 'unknown';
 
    $url = 'http://maps.google.co.uk/m/directions?saddr='.$start.'&daddr='.$finish.'&hl=en&oi=nojs&dirflg=d';
     if($data = file_get_contents($url))
     {
         if(preg_match('@<span[^>]+>([^<]+) (mi|km)</span>@smi', $data, $found))
         {
             $distanceNum    = trim($found[1]);
             $distanceUnit   = trim($found[2]);
 
            if($raw)
             {
                 $distance = $distanceNum.' '.$distanceUnit;
             }
             else
             {
                 $distance = number_format($distanceNum, 2);
                 if(strcmp($distanceUnit, 'km') == 0)
                 {
                     $distance = $distanceNum / 1.609344;
                 }
             }
         }
         else
         {
             throw new Exception('Could not find that route');
         }
 
        if(preg_match('@<b>([^<]*)</b>@smi', $data, $found))
         {
             $timeRaw = trim($found[1]);
 
            if($raw)
             {
                 $time = $timeRaw;
             }
             else
             {
                 $time = 0;
 
                $parts = preg_split('@days?@i', $timeRaw);
                 if(count($parts) > 1)
                 {
                     $time += (86400 * $parts[0]);
                     $timeRaw = $parts[1];
                 }
 
                $parts = preg_split('@hours?@i', $timeRaw);
                 if(count($parts) > 1)
                 {
                     $time += (3600 * $parts[0]);
                     $timeRaw = $parts[1];
                 }
 
                $time += (60 * (int)$timeRaw);
             }
         }
 
        return array('distance' => $distance, 'time' => $time);
     }
     else
     {
         throw new Exception('Could not resolve URL');
     }
 }

Hi Guys

I need a PHP function to which I pass two postcodes and it works out the road distance, I dont mind using google or any other API

I have managed to fing JS ways and php functions using crow route but I really really need a  traffic distance in PHP


Please advice, Help

Thank you

Getting the difference in seconds between two timestamps is easy.  Taking the seconds and doing a breakdown of time frames is also easy.
Code: [Select]
<?php

echo '<p>There are a total of ' . round($seconds) . ' seconds between Timestamp 1 and Timestamp 2.</p>';
echo '<p>There are a total of ' . round($seconds / 60) . ' minutes between Timestamp 1 and Timestamp 2.</p>';
echo '<p>There are a total of ' . round(($seconds / 60) / 1440) . ' days between Timestamp 1 and Timestamp 2.</p>';
echo '<p>There are a total of ' . round((($seconds / 60) / 1440) / 7) . ' weeks between Timestamp 1 and Timestamp 2.</p>';
echo '<p>There are a total of ' . round((((($seconds / 60) / 1440) / 7) / 30)) . ' months between Timestamp 1 and Timestamp 2.</p>';
echo '<p>The total breakdown of time from Timestamp 1 to Timestamp 2 is .</p>';
?>
What I am trying to figure out, is get a collective amount as well....
X years X months X weeks X days X minutes and X seconds.
Does anyone have any good algorithm for handling that, or have any feedback on where to start to handle this type of math.

Hi

i am looping through some history data i have collected via soap. i have the data in an array containing lat, lon and timestamp.

Code: [Select]
foreach($history['data'] as $record) {
echo 'add(jQuery(this), number += 1, "' . date("d-m-Y @ h:i:s",$record['timestamp']) . '", "map_post.php?n=' . $name . 'u=' . $history['user'] . '", "' . $history['user'] . '", "' . $record['latitude'] . '", "' . $record['longitude'] . '");';
}

i wondered it it would be possible to check if each position is within say 300 metres of the last position and if so dont display it?

I use mysql to retrieve data from database and use php to display the data onto website directly by the following codes :
$query2 = "SELECT message FROM messages WHERE username='{$username1}'";
         $result2 = mysql_query($query2,$connection) or die (mysql_error());
         confirm_query($result2);
         while($userinfo = mysql_fetch_array($result2)){
            echo "<div class=\"messagepiece\">" . $userinfo['message'] . "</div><br>";
         }


I want the div(s) arrange style like on the picture http://2aek.com/inventory/divs.jpg
display the 1st 4 divs onto 1st column, jump to 2nd column to display another 4 divs....

Below are the codes of how the divs arrangement : 

<div class="test1" style="left:0px; top:0px;">
asdawdaw
</div>

<div class="test1" style="left:0px; top:70px;">
asdawdaw
</div>

<div class="test1" style="left:0px; top:140px;">
asdawdaw
</div>

<div class="test1" style="left:0px; top:210px;">
asdawdaw
</div>

<div class="test1" style="left:200px; top:35px;">
asdawdaw
</div>

<div class="test1" style="left:200px; top:105px;">
asdawdaw
</div>

<div class="test1" style="left:200px; top:175px;">
asdawdaw
</div>

<div class="test1" style="left:200px; top:245px;">
asdawdaw
</div>

<div class="test1" style="left:400px; top:0px;">
asdawdaw
</div>

<div class="test1" style="left:400px; top:70px;">
asdawdaw
</div>

<div class="test1" style="left:400px; top:140px;">
asdawdaw
</div>

<div class="test1" style="left:400px; top:210px;">
asdawdaw
</div>

So the looping styles should be something like :
loop left 0 for four times > 200 for four times > 400 for four times.
loop top 0 > 70 > 140 > 210 then 35 > 105 > 175 > 245 then again 0 > 70 > 140 > 210.
Seriously I don't know how to write the algorithm of looping.

I guess the looping algorithm for left should be something like :
i = 0 ; i=>4 ; i++{
k=0; k=>20000; k+200{}
}
But it is so wrong, it will stop at 4th loop and each loop will be 0, 200, 400, 800. That's not what I want.

Seriously I can't figure out the algorithm, my brain is stupid, so can you guys guide me please?

Alright, so I have 100 user ids which I need sorted in a very specific way. Right now, they're organized in a 1-100 format. Let's think of each ID as ID#1, ID#2, ID#3 etc all the way up to ID#100. I need to code a script to echo them out in the following order:
$ID2.'<br/>';
$ID1.'<br/>';
$ID4.'<br/>';
$ID3.'<br/>';
$ID6.'<br/>';
$ID5.'<br/>';
//etc up to
$ID100.'<br/>';
$ID99.'<br/>';

Is there any special algorithm or trick with an array to do this? I will attach a file with each ID seperated by a semi-colon. And also here is the script I have right now which echo's them out in order:
<?PHP
$File = "IDs.txt";
$Login = file($File);
$String = file_get_contents($File);
$Logins = explode(";", $String);
foreach($Logins as $Login)

{

echo $Login.'<br/>';

}
?>

I'm decoding some strings that were encoded by someone else, I have the key and already made a decoder in C++ and it is working but I want to avoid call "exec".

For now I've tried to use mcrypt_decrypt (mcrypt Version 2.5.8) with all possible options but none gives correct results, compared to the correct c++ .exe results.

I tried to "convert" the function to PHP around 6 times but none worked, I'm sure there is something I'm missing or I don't know about.

This is the working decoder function in c++:
Code: [Select]
void XTEADecode(LPCVOID lpBuffer, int dwSize, DWORD *lpXteaKey) {
    LPDWORD lpPtr = (LPDWORD)lpBuffer;
    int j;
    for(j=0; j<dwSize; j=j+8){
        unsigned long v0=*lpPtr, v1=*(lpPtr+1), i;
        unsigned long delta=0x9E3779B9, sum=delta*32;
        for(i=0; i<32; i++) {
            v1 -= ((v0 << 4 ^ v0 >> 5) + v0) ^ (sum + lpXteaKey[sum>>11 & 3]);
            sum -= delta;
            v0 -= ((v1 << 4 ^ v1 >> 5) + v1) ^ (sum + lpXteaKey[sum & 3]);
        }
        *lpPtr=v0; *(lpPtr+1)=v1;
        lpPtr+=2;
    }
}
Any suggestions would be appreciated.

Hi, I need to create a secure API at work so that 2 systems can interact with each other and request data (json format). I need to use an API key for this but don't want to use an API key stored in a database, what is the best way to go about this?


I would like to use some sort of encryption algorithm and a white list of a few values to validate against once decrypted, is this safe and are there any algorithms I can use to generate my keys and white list?

I am trying to write a PHP script that implements the MD5 algorithm just so that I can better understand MD5's inner-workings. For those of you already familiar with how MD5 works, could you help me figure out why my script is not producing the correct output?

<?php
$string = "";

$a = "01100111010001010010001100000001"; // 0x67452301
$b = "11101111110011011010101110001001"; // 0xEFCDAB89
$c = "10011000101110101101110011111110"; // 0x98BADCFE
$d = "00010000001100100101010001110110"; // 0x10325476

$aa = $a;
$bb = $b;
$cc = $c;
$dd = $d;

// PADDED BINARY FOR NULL STRING, I.E.: ""
$binary_md5 = "10000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000";
$binary_md5_words = strlen($binary_md5) / 32;

// SPLIT BINARY INTO 16 32-BIT WORDS
for($i = 1; $i <= $binary_md5_words; $i++) {
    $m[] = substr($binary_md5, ($i - 1) * 32, 32);
}

// GENERATE T-VALUES
for($i = 0; $i < 64; $i++) {
    $T[] = Pad(decbin(floor(4294967296 * abs(sin($i+1)))), 32);
}

/*
// PRINT THE M[K] ARRAY
echo "<h1>m[k] Array</h1><br>";
print_r($m);
echo "<br><br>";

// PRINT THE T[t] ARRAY
echo "<h1>T[t] Array</h1><br>";
print_r($T);
echo "<br><br>";

// TEST ANDxy
echo "<h1>Test ANDxy</h1><br>";
echo "$m[0]<br>$T[0]<br>";
echo ANDxy($m[0], $T[0]);
echo "<br><br>";

// TEST ORxy
echo "<h1>Test ORxy</h1><br>";
echo "$m[0]<br>$T[0]<br>";
echo ORxy($m[0], $T[0]);
echo "<br><br>";

// TEST ADDxy
echo "<h1>Test ADDxy</h1><br>";
echo "$m[0]<br>$T[0]<br>";
echo ADDxy($m[0], $T[0]);
echo "<br><br>";

// TEST XORxy
echo "<h1>Test XORxy</h1><br>";
echo "$m[0]<br>$T[0]<br>";
echo XORxy($m[0], $T[0]);
echo "<br><br>";

// TEST NOTx
echo "<h1>Test NOTx</h1><br>";
echo "$m[0]<br>";
echo NOTx($m[0]);
echo "<br><br>";

// TEST SHIFTleft
echo "<h1>Test SHIFTleft</h1><br>";
echo "$m[0]<br>";
echo SHIFTleft($m[0], 1);
echo "<br><br>";

// TEST F
echo "<h1>Test F</h1><br>";
echo "X = $m[0]<br>Y = $m[1]<br>Z = $m[2]<br>F = ";
echo F($m[0], $m[1], $m[2]);
$step1 = ANDxy($m[0], $m[1]);
$step2 = ANDxy(NOTx($m[0]), $m[2]);
$step3 = ORxy($step1, $step2);
echo "<br>F = $step3";
echo "<br><br>";

// TEST H
echo "<h1>Test H</h1><br>";
echo "X = $m[0]<br>Y = $m[1]<br>Z = $m[2]<br>F = ";
echo H($m[0], $m[1], $m[2]);
echo "<br><br>";
*/

// ROUND 1
$a = ff($a, $b, $c, $d, $m, 0, 7, $T[0]);
$d = ff($d, $a, $b, $c, $m, 1, 12, $T[1]);
$c = ff($c, $d, $a, $b, $m, 2, 17, $T[2]);
$b = ff($b, $c, $d, $a, $m, 3, 22, $T[3]);

$a = ff($a, $b, $c, $d, $m, 4, 7, $T[4]);
$d = ff($d, $a, $b, $c, $m, 5, 12, $T[5]);
$c = ff($c, $d, $a, $b, $m, 6, 17, $T[6]);
$b = ff($b, $c, $d, $a, $m, 7, 22, $T[7]);

$a = ff($a, $b, $c, $d, $m, 8, 7, $T[8]);
$d = ff($d, $a, $b, $c, $m, 9, 12, $T[9]);
$c = ff($c, $d, $a, $b, $m, 10, 17, $T[10]);
$b = ff($b, $c, $d, $a, $m, 11, 22, $T[11]);

$a = ff($a, $b, $c, $d, $m, 12, 17, $T[12]);
$d = ff($d, $a, $b, $c, $m, 13, 12, $T[13]);
$c = ff($c, $d, $a, $b, $m, 14, 17, $T[14]);
$b = ff($b, $c, $d, $a, $m, 15, 22, $T[15]);

// ROUND 2
$a = gg($a, $b, $c, $d, $m, 1, 5, $T[16]);
$d = gg($d, $a, $b, $c, $m, 6, 9, $T[17]);
$c = gg($c, $d, $a, $b, $m, 11, 14, $T[18]);
$b = gg($b, $c, $d, $a, $m, 0, 20, $T[19]);

$a = gg($a, $b, $c, $d, $m, 5, 5, $T[20]);
$d = gg($d, $a, $b, $c, $m, 10, 9, $T[21]);
$c = gg($c, $d, $a, $b, $m, 15, 14, $T[22]);
$b = gg($b, $c, $d, $a, $m, 4, 20, $T[23]);

$a = gg($a, $b, $c, $d, $m, 9, 5, $T[24]);
$d = gg($d, $a, $b, $c, $m, 14, 9, $T[25]);
$c = gg($c, $d, $a, $b, $m, 3, 14, $T[26]);
$b = gg($b, $c, $d, $a, $m, 8, 20, $T[27]);

$a = gg($a, $b, $c, $d, $m, 13, 5, $T[28]);
$d = gg($d, $a, $b, $c, $m, 2, 9, $T[29]);
$c = gg($c, $d, $a, $b, $m, 7, 14, $T[30]);
$b = gg($b, $c, $d, $a, $m, 12, 20, $T[31]);

// ROUND 3
$a = hh($a, $b, $c, $d, $m, 5, 4, $T[32]);
$d = hh($d, $a, $b, $c, $m, 8, 11, $T[33]);
$c = hh($c, $d, $a, $b, $m, 11, 16, $T[34]);
$b = hh($b, $c, $d, $a, $m, 14, 23, $T[35]);

$a = hh($a, $b, $c, $d, $m, 1, 4, $T[36]);
$d = hh($d, $a, $b, $c, $m, 4, 11, $T[37]);
$c = hh($c, $d, $a, $b, $m, 7, 16, $T[38]);
$b = hh($b, $c, $d, $a, $m, 10, 23, $T[39]);

$a = hh($a, $b, $c, $d, $m, 13, 4, $T[40]);
$d = hh($d, $a, $b, $c, $m, 0, 11, $T[41]);
$c = hh($c, $d, $a, $b, $m, 3, 16, $T[42]);
$b = hh($b, $c, $d, $a, $m, 6, 23, $T[43]);

$a = hh($a, $b, $c, $d, $m, 9, 4, $T[44]);
$d = hh($d, $a, $b, $c, $m, 12, 11, $T[45]);
$c = hh($c, $d, $a, $b, $m, 15, 16, $T[46]);
$b = hh($b, $c, $d, $a, $m, 2, 23, $T[47]);

// ROUND 4
$a = ii($a, $b, $c, $d, $m, 0, 6, $T[48]);
$d = ii($d, $a, $b, $c, $m, 7, 10, $T[49]);
$c = ii($c, $d, $a, $b, $m, 14, 15, $T[50]);
$b = ii($b, $c, $d, $a, $m, 5, 21, $T[51]);

$a = ii($a, $b, $c, $d, $m, 12, 6, $T[52]);
$d = ii($d, $a, $b, $c, $m, 3, 10, $T[53]);
$c = ii($c, $d, $a, $b, $m, 10, 15, $T[54]);
$b = ii($b, $c, $d, $a, $m, 1, 21, $T[55]);

$a = ii($a, $b, $c, $d, $m, 8, 6, $T[56]);
$d = ii($d, $a, $b, $c, $m, 15, 10, $T[57]);
$c = ii($c, $d, $a, $b, $m, 6, 15, $T[58]);
$b = ii($b, $c, $d, $a, $m, 13, 21, $T[59]);

$a = ii($a, $b, $c, $d, $m, 4, 6, $T[60]);
$d = ii($d, $a, $b, $c, $m, 11, 10, $T[61]);
$c = ii($c, $d, $a, $b, $m, 2, 15, $T[62]);
$b = ii($b, $c, $d, $a, $m, 9, 21, $T[63]);

$a = ADDxy($a, $aa);
$b = ADDxy($b, $bb);
$c = ADDxy($c, $cc);
$d = ADDxy($d, $dd);

// ECHO RESULTS
echo "<h1>String</h1><br>";
echo "String: '$string'<br>";
$md5 = md5($string);
echo "MD5: $md5<br><br>";
$md5_1 = substr($md5, 0, 8);
$md5_2 = substr($md5, 8, 8);
$md5_3 = substr($md5, 16, 8);
$md5_4 = substr($md5, 24, 8);
echo "A = $md5_1<br>B = $md5_2<br>C = $md5_3<br>D = $md5_4<br><br>";
$md5_bin_a = Pad(decbin(hexdec($md5_1)), 32); 
$md5_bin_b = Pad(decbin(hexdec($md5_2)), 32); 
$md5_bin_c = Pad(decbin(hexdec($md5_3)), 32); 
$md5_bin_d = Pad(decbin(hexdec($md5_4)), 32); 
echo "A = $md5_bin_a<br>B = $md5_bin_b<br>C = $md5_bin_c<br>D = $md5_bin_d<br><br>";
echo "<h1>Results</h1><br>";
echo "A = $a<br>B = $b<br>C = $c<br>D = $d<br><br>";
$a_dec = bindec($a);
$b_dec = bindec($b);
$c_dec = bindec($c);
$d_dec = bindec($d);
$a_hex = dechex($a_dec);
$b_hex = dechex($b_dec);
$c_hex = dechex($c_dec);
$d_hex = dechex($d_dec);
echo "A = $a_hex<br>B = $b_hex<br>C = $c_hex<br>D = $d_hex<br><br>";

// FUNCTIONS
function ff($a, $b, $c, $d, $m, $k, $s, $t) {
    //a = b + ((a + F(b,c,d) + X[k] + T[i]) <<< s)
    return ADDxy($b, SHIFTleft(ADDxy(ADDxy(ADDxy($a, F($b, $c, $d)), $m[$k]), $t), $s));
}

function gg($a, $b, $c, $d, $m, $k, $s, $t) {
    //a = b + ((a + G(b,c,d) + X[k] + T[i]) <<< s)
    return ADDxy($b, SHIFTleft(ADDxy(ADDxy(ADDxy($a, G($b, $c, $d)), $m[$k]), $t), $s));
}

function hh($a, $b, $c, $d, $m, $k, $s, $t) {
    //a = b + ((a + H(b,c,d) + X[k] + T[i]) <<< s)
    return ADDxy($b, SHIFTleft(ADDxy(ADDxy(ADDxy($a, H($b, $c, $d)), $m[$k]), $t), $s));
}

function ii($a, $b, $c, $d, $m, $k, $s, $t) {
    //a = b + ((a + I(b,c,d) + X[k] + T[i]) <<< s)
    return ADDxy($b, SHIFTleft(ADDxy(ADDxy(ADDxy($a, I($b, $c, $d)), $m[$k]), $t), $s));
}

function F($X, $Y, $Z) {
    //return ($X & $Y) | ((~$X) & $Z);
    return ORxy(ANDxy($X, $Y), ANDxy(NOTx($X), $Z));
}

function G($X, $Y, $Z) {
    //return ($X & $Z) | ($Y & (~$Z));
    return ORxy(ANDxy($X, $Z), ANDxy($Y, NOTx($Z)));
}

function H($X, $Y, $Z) {
    //return $X ^ $Y ^ $Z;
    return XORxy(XORxy($X, $Y), $Z);
}

function I($X, $Y, $Z) {
    //return $Y ^ ($X | (~$Z));
    return XORxy($Y, ORxy($X, NOTx($Z)));
}

function Pad($binary, $pad_length) {
    $pad_length = $pad_length - strlen($binary);
    for($i = 0; $i < $pad_length; $i++) {
        $padding .= '0';
    }
    return $padding . $binary;
}

function mod($val, $div) {
    $r = $val - (floor($val/$div)*$div);
    return $r;
}
function ANDxy($x, $y) {
    $x_dec = bindec($x);
    $y_dec = bindec($y);
    
    $result = $x_dec & $y_dec;
    $result = Pad(decbin($result), strlen($x));
    
    return $result;   
}

function ORxy($x, $y) {
    $x_dec = bindec($x);
    $y_dec = bindec($y);
    
    $result = $x_dec | $y_dec;
    $result = Pad(decbin($result), strlen($x));
    
    return $result;   
}

function ADDxy($x, $y) {
    $x_dec = bindec($x);
    $y_dec = bindec($y);
    
    $result = mod($x_dec + $y_dec, pow(2, 32));
    $result = Pad(decbin($result), strlen($x));
    
    return $result;   
}

function XORxy($x, $y) {
    $x_dec = bindec($x);
    $y_dec = bindec($y);
    
    $result = $x_dec ^ $y_dec;
    $result = Pad(decbin($result), strlen($x));
    
    return $result;   
}

function NOTx($x) {
    $x_dec = bindec($x);
    
    $result = ~$x_dec;
    $result = Pad(decbin($result), strlen($x));
    
    return $result;
}

function SHIFTleft($x, $y) {
    $x_dec = bindec($x);
    
    $result = $x_dec << $y;
    $result = Pad(decbin($result), strlen($x));
    
    return $result;   
}

function SHIFTright($x, $y) {
    $x_dec = bindec($x);
    
    $result = $x_dec >> $y;
    $result = Pad(decbin($result), strlen($x));
    
    return $result;   
}
?>

Hey all. I am racking my brain trying to figure out the best way to handle a certain process my company needs me to do. First I will give a general description of the issue, then I will get into specifics.

Basically I have a file that contains a bunch of data. The data stored in the file is consistant, each entry has X number of elements with a total character size of Y. Element 1 in each entry will always take up the same amount of characters.

So if I have 2 elements in each data entry, each 5 characters long, then each data entry is 10 characters. Whcih means to access the 2nd element of the 3rd entry I would grab characters 15-20.

I would want to be able to search this data for a number of things. Basically id want to be able to say, "give me all results where element 1 = 'pancakes'. Or where element 2 >8. Or more substaintial searches such as element 1>10 AND element 2<5.

Is there a good way to do this?

My first line of thought would be to run through the file, grabbing every element that can be searched on. So lets say if elements 2 and 4 can be searched on, and I have 10 entries, I would run through and grab an array holding  the values for entry 2 and 4.

array(
 array('index=>0', 'element2'=>10, 'element4'=>12),
 array('index=>1', 'element2'=>11, 'element4'=>-2),
 array('index=>2', 'element2'=>0, 'element4'=>7)
)

Then, depending on the search,  I would reorder the array and search through it. So if I wanted to see if element2 was greater then 8, id reorder by element2 and then search. As if this wasnt difficult enough, the issue would be on complex searches such as 'element1>10 OR (element2=6 AND element3=0)'

I suppose i could store the result array of each individual search result and then merge/union/intersect based on the AND/OR.

To make things ever CRAZIER, the flat files can have other flat files as children. So if I have element1 in file 1 and element1 in file 2, all of file2 data would be part of the corrisponding data in file1.

So, id basically need to be able to "join" files. I have thought of a number of solutions, but im not sure how they will pan out.

Ugh.

In case your wondering WHY I need to do this. My company runs a lot of data off an old database called filepro which uses flat files with index and map files. Right now we have a few systems which weve "synched" with mysql which runs batch updates between the two databases to keep data consistant.

We wont be coming "off" of filepro for a long, long time. But a lot of my php/mysql apps need access to the data on filepro. So, Im trying to find a way to quickly be able to search and pull data from filepro into php. Basically, i want to run search queries on the flat files.

Basically id like your input on a number of things:

Is this even a reasonable attempt?

Is the idea of pulling the searched elements into php to actually run the search, then collecting the correct rows and getting the data directly from them a smart move?

Once I have the searchable elements and index, what algorithms are good for actually running the search?

I am trying to find a tutorial on how to perform a depth first search. I've seen pseudocodes and sources in other languages, but I just can't implement it in PHP no matter what I try. Can anyone show me how or where I can read up on it or how to do it?

Hello Guys, You  might have known about Luhn Algorithm, which is used to get checksum of IMEI of phones, credit cards etc etc. It is a public domain so it is not used for security but to ensure that client has passed the correct numbers etc etc.   Anyway, I am trying to get my hands on this algorithm and I will build a logic based on luhn algo to get the checksum, where I am stuck is how can I get the alternate numbers from a numeric string, for example I have written the following code to get all the numbers one by one into the array.

$imei = "356565451265856";
$lenOfStr= strlen($imei);
$myArray = array();

//Get all numbers one by one in array
for($i=0; $i < $lenOfStr; $i++){
  $myArray[] = substr($imei,$i,1);
}

// Checking the array
foreach($myArray as $seperatedNumbers){
  echo $seperatedNumbers;
}

No the problem is that I want to select every 2nd number from right to left e-g 5,5,2,... or 6,8,6 How can I get it done?   This logic may not be so good, there may be more brilliant solutions to write luhn algo, but I want to try myself once...    Thanks.
Edited by Digitizer, 31 August 2014 - 04:53 PM.

Hello,

I'm building a blog post website, and now I'm on the search part of it.

I have a search field which I instruct the user to type in "keywords" they want to search for. The words they type in there are then to be searched in the "title" and "content" of each post in the "posts" table.

Here's an example query of my current setup:

SELECT * FROM (`posts`) WHERE MATCH(title,content) AGAINST('+term1* ' IN BOOLEAN MODE);

This works fine if I have one or two words in they keywords. If I, however, copy and paste an entire sentence from an existing blog post, no results are found ???
Here's an example of a query where I just copy+pasted a sentence from a blog post:

SELECT * FROM (`posts`) WHERE MATCH(title,content) AGAINST('+Hello* +everyone* +my* +name* +is* +Bob* ' IN BOOLEAN MODE);

Yet, a search for just "Bob" returns the proper result. WHY? What's a better way to perform this search?!

Hallo everybody! I am looking for some information about creating PHP threaded forum (with MySQL). BB forum is easy - db table with forums, topics and posts, every post has foreign key to topic, topic to forum and it's done. But if I want something like Disqus, how to do this more efficiently? How to collect posts in db with minimum query needed to render any thread? And what about post rating? How to prevent user from sending more then one rating?