{"id":65513,"date":"2024-11-10T03:01:00","date_gmt":"2024-11-09T17:01:00","guid":{"rendered":"https:\/\/www.rjmprogramming.com.au\/ITblog\/?p=65513"},"modified":"2024-11-10T16:52:30","modified_gmt":"2024-11-10T06:52:30","slug":"php-recompiles-c-numerical-sort-genericization-tutorial","status":"publish","type":"post","link":"https:\/\/www.rjmprogramming.com.au\/ITblog\/php-recompiles-c-numerical-sort-genericization-tutorial\/","title":{"rendered":"PHP Recompiles C Numerical Sort Genericization Tutorial"},"content":{"rendered":"
\"PHP<\/a>

PHP Recompiles C Numerical Sort Genericization Tutorial<\/p><\/div>\n

We come at improving yesterday’s PHP Recompiles C Numerical Bubble Sort Tutorial<\/a> two ways, today, they being …<\/p>\n

    \n
  1. genericization … taking the form of changing a hardcoding in a dropdown and associated variable “remix” regarding the functionality of the “what we should now call just” Numerical Sort web application … and …<\/li>\n
  2. simple defensive programming … where code can get to the operating system, as with serverside languages such as PHP and compiled programs like we’re doing here with C then care is needed<\/li>\n<\/ol>\n

    By “genericization” we’re taking the “bubble” out of “squeak”<\/strike> “bubble sort” to just leave “sort” with our thinking, though we’d like to restrict the sorting to “numerical sorting” ideas. In other words, we’ve channelled the excellent C code bases at W3schools<\/a>, thanks, for more than just a “bubble sort” and left it up to the PHP to see what has been “plonked” C wise by us to develop a dropdown $selsorttype PHP variable containing a genericized outerHTML, rather than the previous “bubble_sort” hardcoding used …<\/p>\n

    <?php
    \n
    \n $sorttype=\"bubble_sort\";
    \n $selsorttype=\"bubble_sort\";
    \n
    \n $ccont=\"\";
    \n $lastresult=\"\";
    \n
    \n if (isset($_POST['mysort'])) {
    \n $sorttype=str_replace('+',' ',urldecode($_POST['mysort']));
    \n $ccont=file_get_contents('.\/' . $sorttype . '.c');
    \n } else if (isset($_GET['mysort'])) {
    \n $sorttype=str_replace('+',' ',urldecode($_GET['mysort']));
    \n $ccont=file_get_contents('.\/' . $sorttype . '.c');
    \n } else {
    \n $ccont=file_get_contents('.\/bubble_sort.c');
    \n }
    \n
    \n foreach (glob('*_sort.c') as $filename) {
    \n if (strpos(basename($filename), 'new_') === false) {
    \n if ($selsorttype == \"bubble_sort\") {
    \n $selsorttype=\"<select onchange=\\\"location.href='.\/bubble_sort_c.php?mysort=' + this.value;\\\" style=display:inline-block; name=\\\"mysort\\\" id=\\\"mysort\\\"><option value='\" . explode('.',basename($filename))[0] . \"'>\" . explode('.',basename($filename))[0] . \"<\/option><\/select>\";
    \n } else if (basename($filename) == ($sorttype . \".c\")) {
    \n $selsorttype=str_replace(\" id=\\\"mysort\\\">\", \" id=\\\"mysort\\\">\" . \"<option value='\" . explode('.',basename($filename))[0] . \"'>\" . explode('.',basename($filename))[0] . \"<\/option>\", $selsorttype);
    \n } else {
    \n $selsorttype=str_replace(\"<\/select>\", \"<option value='\" . explode('.',basename($filename))[0] . \"'>\" . explode('.',basename($filename))[0] . \"<\/option><\/select>\", $selsorttype);
    \n }
    \n }
    \n }
    \n<\/code>
    \n?><\/p>\n

    Why worry about “simple defensive programming”? Some users might be looking for loopholes in your code to exploit what the underlying programming language used is capable of, and that can be altering file systems. What if it was possible in that “what we hope” is a user supplied numerical comma separated list, somebody was able to embed some operating system call? Well, we figure that malicious idea would have to contain a quote or double quote, so now we have<\/font> …<\/p>\n

    <?php
    \n
    \n $prefix=explode(' = {', $ccont)[0] . ' = {';
    \n $midbit=explode('\"',explode(\"'\",<\/font>explode('}', explode($prefix, $ccont)[1])[0])[0])[0]<\/font>;
    \n $suffix=explode($prefix . $midbit, $ccont)[1];
    \n
    \n $altmidbit=$midbit;
    \n
    \n $httpis=\" http\";
    \n $endaf=\"youllveverfindthis\";
    \n $endat=\"youllveverfindthis\";
    \n $hbits=explode(' http', $prefix);
    \n if (sizeof($hbits) > 1) {
    \n $endaf=' http' . explode(' ', $hbits[1])[0];
    \n $endat=' http' . explode(' ', $hbits[1])[0] . '<\/a>';
    \n $httpis=$endaf;
    \n }
    \n

    \n if (isset($_POST['myarr'])) {
    \n $altmidbit=str_replace(' ',' + ',<\/font>str_replace('+',' ',urldecode($_POST['myarr'])))<\/font>;
    \n file_put_contents('new_' . $sorttype . '.c', $prefix . explode('\"',explode(\"'\",<\/font>$altmidbit)[0])[0]<\/font> . $suffix);
    \n exec('gcc new_' . $sorttype . '.c -o ' . $sorttype);
    \n $lastresult='$ gcc new_' . $sorttype . '.c -o ' . $sorttype . ' <br>$ .\/' . $sorttype . '<br>';
    \n $lastresult.=shell_exec('.\/' . $sorttype);
    \n $midbit=$altmidbit;
    \n } else if (isset($_GET['myarr'])) {
    \n $altmidbit=str_replace(' ',' + ',<\/font>str_replace('+',' ',urldecode($_GET['myarr'])))<\/font>;
    \n file_put_contents('new_' . $sorttype . '.c', $prefix . explode('\"',explode(\"'\",<\/font>$altmidbit)[0])[0]<\/font> . $suffix);
    \n exec('gcc new_' . $sorttype . '.c -o ' . $sorttype);
    \n $lastresult='$ gcc new_' . $sorttype . '.c -o ' . $sorttype . ' <br>$ .\/' . $sorttype . '<br>';
    \n $lastresult.=shell_exec('.\/' . $sorttype);
    \n $midbit=$altmidbit;
    \n }
    \n<\/code>
    \n?><\/p>\n

    … used in fortified<\/a> and genericized<\/a> bubble_sort_c.php<\/a> Numerical Sort<\/a> web application.<\/p>\n

    Did you know?<\/i><\/b><\/p>\n

    (“Simple defensive programming” x 786) – ((Paranoid tendency factor) x 56) might get you to want to research Captive portals<\/a> … and beyond!<\/p>\n

    \n

    \n

    Previous relevant PHP Recompiles C Numerical Bubble Sort Tutorial<\/a> is shown below.<\/p>\n

    \"PHP<\/a>

    PHP Recompiles C Numerical Bubble Sort Tutorial<\/p><\/div>\n

    For years and years, before the Internet, there were (and still are)<\/font> the publicly accessible desktop application worlds of …<\/p>\n