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dcblogdev/gist:6174117

Created August 7, 2013 13:38
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  1. David Carr created this gist Aug 7, 2013.
    34 changes: 34 additions & 0 deletions gistfile1.php
    View file
    Original file line number Diff line number Diff line change
    @@ -0,0 +1,34 @@
    <?php
    session_start();
    header("Expires: Mon, 26 Jul 1997 05:00:00 GMT");
    header("Last-Modified: " . gmdate("D, d M Y H:i:s") . " GMT");
    header("Cache-Control: no-store, no-cache, must-revalidate");
    header("Cache-Control: post-check=0, pre-check=0", false);
    header("Pragma: no-cache");

    function _generateRandom($length=6)
    {
    $_rand_src = array(
    array(48,57) //digits
    , array(97,122) //lowercase chars
    // , array(65,90) //uppercase chars
    );
    srand ((double) microtime() * 1000000);
    $random_string = "";
    for($i=0;$i<$length;$i++){
    $i1=rand(0,sizeof($_rand_src)-1);
    $random_string .= chr(rand($_rand_src[$i1][0],$_rand_src[$i1][1]));
    }
    return $random_string;
    }

    $im = @imagecreatefromjpeg("captcha.jpg");
    $rand = _generateRandom(3);
    $_SESSION['captcha'] = $rand;
    ImageString($im, 5, 2, 2, $rand[0]." ".$rand[1]." ".$rand[2]." ", ImageColorAllocate ($im, 0, 0, 0));
    $rand = _generateRandom(3);
    ImageString($im, 5, 2, 2, " ".$rand[0]." ".$rand[1]." ".$rand[2], ImageColorAllocate ($im, 255, 0, 0));
    Header ('Content-type: image/jpeg');
    imagejpeg($im,NULL,100);
    ImageDestroy($im);
    ?>