Debian 8 does not execute /etc/rc.local

I have just installed a fresh Debian 8 Jessie and then I put something in /etc/rc.local.
To my suprise, after the reboot, the command did not execute.
Log investigation showed:

Failed to start /etc/rc.local Compatibility.
Failed at step EXEC spawning /etc/rc.local: Exec format error

So I simply added "#!/bin/sh -e" in the first line of rc.local and then it worked well.

Youtube mp3 extract in Debian Linux

youtube-dl --extract-audio --audio-format mp3 [URL]

HITACHi Air Conditioner green light turn off

Since last year I have a HITACHI Air Conditioner and the technician told me to clean the filters every two weeks, but he didn't mention anything about the green led. So after a while, this green light turned on, I noticed it has something to do with the filters so I have cleaned them hoping it has some sensor and will turn off automatically. But it didn't. Later I found you have to press the AUTO SWING from the remote while the unit is off. And after 200 hours of functioning it will turn on again to remind you about cleaning the filters.

Pasting source code in friendly format

Here are three tools you can use to paste source codes:

http://codeformatter.blogspot.de
http://hilite.me/
http://markup.su/highlighter/

Mass kill processes in MySQL "show processlist"

So your server load is high you did "SHOW PROCESSLIST;" and you noticed many slow queries and you want to kill them.
If the list is too long to do it manually, you may want to try this way:

<?php

include("mySqlClass.inc.php");

$serv="localhost";
$user="root";
$pass="YOUR_PASS";
$database="SOME_DB";


$link = new mySqlClass();
$link->Connect($serv,$user,$pass,$database);
$result=$link->SqlQuery("SHOW FULL PROCESSLIST");
while ($result->NextRow()) {
    $process_id=$result->field["Id"];
    if ($result->field["Time"]>200) $link->SqlQuery("KILL $process_id");
}   

?>

and the mySqlClass.inc.php:

<?php

class mySqlClass {

  public $query_count;
  public $query_time;

  private $database;
  public $link;
  private $db_connected;

  function __construct()
  {
    $this->query_count = 0;
    $this->query_time = 0;
  }

  public function Connect($host, $user, $password, $database)
  {
    $this->database = $database;

    $this->link = @mysql_connect($host, $user, $password, true);

    if ($this->link)
    {
      if (@mysql_select_db($database, $this->link))
      {
        $this->db_connected = true;
        return true;
      }
    }

    $this->_error(mysql_errno(), mysql_error());
    return false;
  }

  public function SqlQuery($sql)
  {
    $time_start = explode(' ', microtime());

    if (!$this->db_connected) $this->_error(0, 'Error: MySQL DB Not Connected');

    $result_resource = @mysql_query($sql, $this->link);

    if (!$result_resource) $this->_error(@mysql_errno($this->link), @mysql_error($this->link));

    $obj = new SqlQueryResult($result_resource);

    if ($obj->RowCount() > 0)
    {
      // Return the first row of data results
      $result_array = @mysql_fetch_array($result_resource, MYSQL_ASSOC);

      if ($result_array)
      {
        while (list($key, $value) = each($result_array))
        {
          $obj->field[$key] = $value;
        }
      }
    }

    $time_end = explode (' ', microtime());
    $query_time = $time_end[1]+$time_end[0]-$time_start[1]-$time_start[0];
    $this->query_time += $time_end[1] + $time_end[0] - $time_start[1] - $time_start[0];
    $this->query_count++;

    return($obj);
  }

  public function QueryCount()
  {
    return $this->query_count;
  }

  public function QueryTime()
  {
    return $this->query_time;
  }

  private function _error($error_number, $error_text)
  {
    if ($error_number != 1141)
    {
      echo "Error #$error_number: $error_text";
      die();
    }
  }
}


class SqlQueryResult {

  public $field;

  private $result_resource;
  private $num_rows;
  private $current_row;

  function  __construct($result_resource)
  {
    $this->result_resource = $result_resource;
    $this->current_row = 0;
    $this->num_rows = @mysql_num_rows($this->result_resource);
    $this->field = array();
  }

  public function NextRow()
  {
    if ($this->current_row === 0)
    {
      // Row already fetched from SqlQuery() function
      // Do nothing
    }
    else if ($this->num_rows > 0 AND $result_array = @mysql_fetch_array($this->result_resource, MYSQL_ASSOC))
    {
      // This is the next iteration and there is a counted row returned
      // Grab data array
      if ($result_array)
      {
        while (list($key, $value) = each($result_array))
        {
          $this->field[$key] = $value;
        }
      }
    }
    else
    {
      // No more rows, end of data iteration
      // End result
      return false;
    }

    $this->current_row++;

    return true;
  }

  public function RowCount()
  {
    return $this->num_rows;
  }
}

Anagram and Rhyme Generator

I had some fun today with Anagram Generator and Rhyme Generator. For those who are unfamiliar with these, anagrams are rearrangements of the letters in a word. And of course, the rhyme tool is very useful if you want to do poetry.

Allow PHP in Posts and preg_match

Allow PHP in Posts is a very cool plugin when you need to execute PHP in your posts, but you need a little time to get used to it, because it is kind of tricky. For instance I did not manage to use the preg_match function with square brackets. It simply replaces [a-z] with <a-z>. The only fix I could find is to use Code Snippets and add all the preg_match parts there, then use Shortcodes like [php function=5].

Also don't forget about [PHP debug=1] option which can be really useful.