Linux & Web Development Geek - Tips & Tricks

How to export all mysql databases at once:

mysqldump -u root -p --all-databases > alldb.sql

mysql -u root -p < alldb.sql

How to fix Too many redirects occurred Error in Joomla!

Too many redirects occurred trying to open http://mywebsite.com/Joomla_3/index.php " how do I fix this?

How to echo or print PHP script while its still executing?

ob_start();

/*
 * Generate your output here
 */ 

// Ignore connection-closing by the client/user
ignore_user_abort(true);

// Set your timelimit to a length long enough for your script to run, 
// but not so long it will bog down your server in case multiple versions run 
// or this script get's in an endless loop.
if ( 
     !ini_get('safe_mode') 
     && strpos(ini_get('disable_functions'), 'set_time_limit') === FALSE 
){
    set_time_limit(60);
}

// Get your output and send it to the client
$content = ob_get_contents();         // Get the content of the output buffer
ob_end_clean();                      // Close current output buffer
$len = strlen($content);             // Get the length
header('Connection: close');         // Tell the client to close connection
header("Content-Length: $len");     // Close connection after $len characters
echo $content;                       // Output content
flush();                             // Force php-output-cache to flush to browser.
                                     // See caveats below.

// Optional: kill all other output buffering
while (ob_get_level() > 0) {
    ob_end_clean();
}

SQL Injections are Common nowadays!

• When you are going to embed strings in HTML for example when you "print" or when you "echo"  you should default to escape the string using htmlspecialchars(); .
• Never trust user's input, always sanitize the user input by first sanitizing it properly and before performing any SQL query, this can be achieved by mysql_real_escape_string($parameter).Where $parameter is the input you are about to filter.
• Disable Magic Quotes.
• Use prepared statements and parameterized queries, always filter the user inputs properly,thoroughly and strictly.
• Don't through mysql_error() to the user,don't even let them know something happened out there,most of the people use it like, die(mysql_error()); . Instead of just throwing this error straight away to the user you can write your custom messages, prepare some log files or even create a mail() function so you get notified whenever someone tries to pull something off the routine.
• Log,Log,Log, always log the errors and warning messages, turn off error reporting on live websites and enable only when debugging or during development process or testing phases.
• Be Self-Aware, never give up, always try up-to-date security precautions, create difficult random passwords for database, encrypt all the user's information in the database and set a value of 666 to the files which contains configuration for mySQL access.
• Keep your server patched and updated, use only latest software's, if you are on a shared hosting server, and find something which is not fine, notify the Administrator.
• If you are using some software's like WordPress,Joomla,Drupal or any other free and open-source or even other software's,keep them updates, most of these products have built-in update notifiers in the Admin panel's and most of the time they update themselves with a single click.

1. Using PDO:

   $stmt = $pdo->prepare('SELECT * FROM employees WHERE name = :name');
   
   $stmt->execute(array(':name' => $name));
   foreach ($stmt as $row) {
       // do something with $row
   }
   

2. Using mysqli:

   $stmt = $dbConnection->prepare('SELECT * FROM employees WHERE name = ?');
   $stmt->bind_param('s', $name);
   
   $stmt->execute();
   
   $result = $stmt->get_result();
   while ($row = $result->fetch_assoc()) {
       // do something with $row
   }
   

PDO

$dbConnection = new PDO('mysql:dbname=dbtest;host=127.0.0.1;charset=utf8', 'user', 'pass');

$dbConnection->setAttribute(PDO::ATTR_EMULATE_PREPARES, false);
$dbConnection->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);

Explanation

$preparedStatement = $db->prepare('INSERT INTO table (column) VALUES (:column)');

$preparedStatement->execute(array(':column' => $unsafeValue));

function checkurl($url)
  return filter_var($url, FILTER_VALIDATE_URL);
}​

$today = new DateTime(date('y-m-d h:m:s'));

echo $pastDate->y; //return the difference in Year(s).
echo $pastDate->m; //return the difference in Month(s).
echo $pastDate->d; //return the difference in Day(s).
echo $pastDate->h; //return the difference in Hour(s).
echo $pastDate->i; //return the difference in Minute(s)
echo $pastDate->s; //return the difference in Second(s). ​​​

$pid = "9252";$wmi = new COM('winmgmts://'); $process = $wmi->ExecQuery("SELECT * FROM Win32_Process WHERE ProcessId ='".$pid."'"); $pDate = floor($process->CreationDate);    $formatDate = date_parse($pDate);$time = $formatDate['hour'].':'.$formatDate['minute'].':'.$formatDate['second'];print $time;​