Setting up a blog using Ghost on Debian

My web hosting’s annual payment date was drawing close, and instead of renewing it, I decided I’d rent a server on Digital Ocean for 10$ a month. It turns out to be a lot more expensive but gives me the option to use the server for something other than just blogging and running PHP application.

After shifting to this new server, the first thing to do was to migrate my blog here. WordPress is an amazing platform, but over the years it has evolved to something a lot more than just a blogging tool. Besides the new kid on the block – Ghost, was creating a lot of buzz for its simplicity. I wanted to give it a try.

I setup my Digital Ocean server with Debian (Jessie 8.2). Node.js is required to run Ghost. Since I wanted to use this server for multiple applications, I decided I’d put nginx as a front facing proxy/compression server.

This blog item is a guide for setting up Ghost on a server running Debian. Let’s start,

Continue reading “Setting up a blog using Ghost on Debian”

My tools on Linux

Update 2016-01-16

Development of Crunchbang has now stopped. There are a few community spin-offs available, Bunsen Labs and Crunchbang++. I’m now using a netinst version of Debian at home with the i3 window manager, and Bunsen Labs on my office laptop. Both are working well. I’m still using the same set of software for my work, in addition to a few more, so this post is still valid.


I’ve been using Linux at home and work for over 5 months now. I’m using a Debian based distribution called Crunchbang. Over these past few months I’ve developed/programmed using multiple technologies and have gathered a collection of tools, that I use on a daily basis.

NameTypeLink
Eclipse with NodeEclipse – Check UpdateIDE for Node.jsLink
NetbeansIDE for PHPLink
DbeaverGUI client for Cassandra and othersLink
MySQL WorkbenchMySQL/MariaDB GUI clientLink
DiaFlowchart and DiagramsLink
SoapUITesting – API and Web ServicesLink
TildaDrop down terminalLink
MeldMergetoolLink
RemminaGTK RDP ClientLink
TomboyNote Taking AppLink
GMTPMTP ClientLink
GIMPImage manipulationLink
Continue reading “My tools on Linux”

Handling JSON request in PHP

I’ve been working with PHP and jQuery AJAX quite a bit lately. Along with sending form data to PHP page through AJAX, I’ve written restful web services in PHP that receive data in JSON format.

In general when you are sending data through jQuery AJAX to PHP, you don’t have to specify a contentType. Depending on your type ‘GET’ or ‘POST’, PHP will nicely wrap your content into either the $_POST or $_GET global arrays. When you don’t specify a contentType the default contentType is taken as application/x-www-form-urlencoded; charset=UTF-8’.

Following is the request headers from an AJAX call without contentType specified,

GET /ajax-php/api.php?firstname=Abijeet&lastname=Patro HTTP/1.1 
Host: localhost:8081 
Connection: keep-alive 
Cache-Control: no-cache Pragma: no-cache 
Accept: */* 
X-Requested-With: XMLHttpRequest 
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Referer:http://localhost:8081/ajax-php/index.php
Accept-Encoding: gzip,deflate,sdch 
Accept-Language: en-US,en;q=0.8,fr;q=0.6

To further test this, I set up the following PHP code on my server,

<?php
$get=$_GET;
$post=$_POST;
$app_json=json_decode(file_get_contents('php://input');
$response=array();
$response['GET']=$get;
$response['POST']=$post;
$response['JSON']=$app_json;
echo json_encode($response);
die();

The response that for the above request case was,

{
  "GET": {
    "firstname": "Abijeet",
    "lastname": "Patro"
  },
  "POST": [],
  "JSON": null
}

If we put the jQuery AJAX type property as ‘POST’ we will have the following request header,

POST /ajax-php/api.php HTTP/1.1 
Host: localhost:8081 
Connection: keep-alive 
Content-Length: 32 
Cache-Control: no-cache 
Pragma: no-cache 
Origin: http://localhost:8081
X-Requested-With: XMLHttpRequest 
Content-Type: application/x-www-form-urlencoded; 
charset=UTF-8 
Accept: */* 
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36 
Referer: http://localhost:8081/ajax-php/index.php
Accept-Encoding: gzip,deflate,sdch 
Accept-Language: en-US,en;q=0.8,fr;q=0.6

Nothing much changes. The action is specified as POST and the data is no longer a part of the request header. The response from the server is following,

{
  "GET": [],
  "POST": {
    "firstname": "Abijeet",
    "lastname": "Patro"
  },
  "JSON": null
}

Obviously, PHP has no issues parsing content of type – application/x-www-form-urlencoded; charset=UTF-8. As soon as it sees that contentType, it checks the action and packs the data nicely into either $_GET or $_POST.

Let’s now talk about JSON data. In general, restful web services accept data of type JSON. When sending data via JSON the contentType for jQuery AJAX is application/json; charset=UTF-8

This is the request header,

POST /ajax-php/api.php HTTP/1.1 
Host: localhost:8081 
Connection: keep-alive 
Content-Length: 42 
Cache-Control: no-cache 
Pragma: no-cache 
Origin: http://localhost:8081
X-Requested-With: XMLHttpRequest 
Content-Type: application/json; charset=UTF-8
Accept: */* 
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/36.0.1985.143 Safari/537.36 
Referer: http://localhost:8081/ajax-php/index.php
Accept-Encoding: gzip,deflate,sdch 
Accept-Language: en-US,en;q=0.8,fr;q=0.6

When PHP receives this data and looks at the content type, it’s not quite sure how to process it, so it leaves it alone. In this case the action – ‘POST’ or ‘GET’ doesn’t matter. You’ll notice that $_POST or $_GET both, are empty arrays. Now, it’s up to you to read this data and parse it.

<?php
$app_json=json_decode(file_get_contents('php://input'));

The code above, reads the data from PHP’s input stream. Since we have passed a JSON string, we decode it, which converts it to a PHP array and stores it in $app_json. If the data you send is not in a correct JSON format, $app_json will have false.

When we echo our response, we get the following on the client side,

{
  "GET": [],
  "POST": [],
  "JSON": {
    "firstname": "Abijeet",
    "lastname": "Patro"
  }
}

I set up a small project to illustrate what has been written here. You can find it over on my GitHub page

Continue reading “Handling JSON request in PHP”

get_results PHP function not working on CentOS

There are instances where the PHP function – get_results will not work on CentOS (this maybe the case with other Linux based operating systems as well). I faced this issue while deploying a project on CentOS which was originally developed on Windows. All my INSERT, UPDATE and DELETE database statements were working properly, but bulk SELECTstatements had issues. Closer inspection narrowed down the problem to the get_results function.

I came across this on the get_results PHP documentation page –

MySQL Native Driver Only
Available only with mysqlnd.

I was able to determine if mysqlnd driver was installed using this post on StackOverflow as reference. As expected, it wasn’t.

Here’s the relevant php code from the StackOverflow post –

<?php
$mysqlnd=function_exists('mysqli_fetch_all');
if($mysqlnd) {
   echo 'mysqlnd enabled!';
}

Now that I new that we needed to install the mysqlnd driver, here are the steps that I followed to get the mysqlnd driver working on CentOS,

// First remove the existing MySQL driver
yum --enablerepo=remi,remi-test remove php-mysql

// Then go ahead and install mysqlnd
yum --enablerepo=remi,remi-test install php-mysqlnd

// Restart httpd
/sbin/service httpd restart

// If you have phpMyAdmin, re-install it so that it uses the new MySQL driver
yum remove phpMyAdmin
yum install phpMyAdmin

After installing the mysqlnd driver the get_results function worked just fine.

Tree view based file explorer for the web using jQuery.

This post assumes that the reader has a basic understanding of PHP, jQuery and jQuery $.post

Recently I had to implement a windows-esque tree view based file explorer for one of my projects at work. I ended up using this wonderful jQuery plugin to help me. In this blog I’ll be going through some basic code to get it working using PHP on the server side.

To whet your appetite, here’s what we’ll be achieving in this blog post – A complete tree view based file explorer that feeds from a folder on the server’s file system.

File tree view

So let’s get started!

To be able to render a proper tree using the aciTree plugin, we’ll need to send JSON from server in the following format –

[
  {
    "id": "folder_1",
    "label": "ThisisFolder1",
    "inode": true,
    "open": false,
    "icon": "folder",
    "branch": [
      {
        "id": "sub-item_x",
        "label": "ThisisFileX",
        "inode": false,
        "icon": "file"
      },
      {
        "...": "..."
      },
      {
        "...": "..."
      }
    ]
  },
  {
    "id": "file_1",
    "label": "ThisisFile1",
    "inode": false,
    "icon": "file"
  },
  {
    "...": "..."
  },
  {
    "...": "..."
  }
]

Here’s the list of things that we’ll be doing –

  1. Server Side Code
  2. HTML
  3. JavaScript/jQuery code to communicate with the server.
  4. Basic event handling for the aciTree plugin.

1. Server side code

Let’s move onto the PHP code. Our job is to read the files from the specified folder and return a JSON structure that resembles what’s shown above. If you look closely you’ll observe that the JSON above is basically an array of objects of with properties as – id, label, inode, icon, open

The following class is exactly similar to that of the class received via JSON. We’ll be returning an array of NodeList objects from the server.

<?php
/**
 * Represents each node in the aci tree jquery plugin
 * 
 * @author abijeet
 */
class NodeList {
    public $id, $label, $inode, $open, $icon, $branch;
    private $openIfBranch;

    /**
     * Constructor for NodeList
     *
     * @param string $label
     *          Label of the node
     * @param boolean $open
     *          If this is a branch, should it be open
     * @param string $icon
     *          Icon for the node
     */
    public function __construct($label, $open, $id, $icon = '') {
        if ($id) {
            $this->id = $id;
        }
        $this->label = basename($label);
        $this->open = false;
        $this->openIfBranch = $open;
        $this->icon = $icon;
        $this->inode = false;
    }

    public function setBranch($branch) {
        $this->branch = $branch;
        $cntBranch = count($branch);
        if ($cntBranch > 0) {
            $this->inode = true;
            $this->label .= ' [' . $cntBranch . ']';
        }
        $this->open = $this->openIfBranch;
    }
}

Now to read the list of files and folders from a location on the server –

<?php
/**
 * Function that given a path, returns an array of nodeList
 * This can then be converted to a json format.
 * 
 * @param $path Path
 *          of the folder from which to retrieve
 * @return multitype:NodeList Returns the json tree
 */
function jsonForResTree($path) {
    $dirArray = getAllFilesAndFolders($path);
    $nodeArray = array ();
    $node = '';
    $cnt = count($dirArray);
    for($i = 0; $i < $cnt; ++ $i) {
        $node = new NodeList($dirArray[$i], false);
        if (is_dir($dirArray[$i])) {
            // Recursion - It's a folder, get the array of nodeList for it.
            $nodeList = jsonForResTree($dirArray[$i]);
            // Add it as branch
            $node->setBranch($nodeList);
        }
        $nodeArray[] = $node;
    }
    return $nodeArray;
}

/**
 * Gets all files and folders from the specified path
 * 
 * @param unknown $path
 *          Path of the folder from where files and folders are to be retrieved
 * @return multitype:
 */
function getAllFilesAndFolders($path) {
    if (! is_dir($path)) {
        return array ();
    }
    $path = $path . DIRECTORY_SEPARATOR . '*';
    return glob($path, GLOB_NOSORT);
}

Some code to handle the request that we will be making from the client side and then echoing the output in JSON format –

<?php
if (! empty($_POST['method'])) {
    // Do some check before handling the POST data.
    $methodToCall = $_POST['method'];
    ob_clean();
    // Call the method requested from the client side.
    $result = call_user_func($methodToCall);
    die(json_encode($result));
}

/**
 * Function that is call by the JQUERY post.
 * 
 * @return multitype:NodeList
 */
function getJsonTree() {
    // Folder Path from where we are going to show the tree view.
    $pathToGetAciTree = './cakephp';
    $jsonTree = jsonForResTree($pathToGetAciTree);
    return $jsonTree;
}

Okay so we have the PHP code in place. Next order of things –

  1. Server Side Code
  2. HTML
  3. JavaScript/jQuery code to communicate with the server.
  4. Basic event handling for the aciTree plugin.

2. HTML

The following HTML goes inside the body tag-

<!-- Scripts and CSS to be loaded. This will be avaliable when you download aciTree plugin --> 
<link href="css/aciTree.css" rel="stylesheet" type="text/css" /> 
<link href="css/demo.css" rel="stylesheet" type="text/css" /> 

<!-- Loading jQuery --> 
<script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script> 
<!-- Loading the aciTree plugin --> 
<script type="text/javascript" src="js/jquery.aciPlugin.min.js"></script> 
<!-- Loading the aciTree core--> 
<script type="text/javascript" src="js/jquery.aciTree.core.js"></script> 
<!-- Loading the aciTree selectable plugin --> 
<script type="text/javascript" src="js/jquery.aciTree.selectable.js"></script> <!-- The div that will contain the ACI Tree --> 
<div id="fsTree"></div> 
<button id="btnGetTreeView">Get Tree View</button> 
<button id="btnRefreshTreeView">Refresh Tree View</button> 
<div id="currStatus"></div>

Next, the JavaScript/jQuery to get the aciTree plugin working. This should be put inside the document’s ready handler –

3. jQuery code to communicate with the server

$currStatus = $('#currStatus');
// Makes the ajax call and fetches the json for the resource tree.
$('#btnGetTreeView').click(function() {
  $("#fsTree").aciTree({
    ajax: {
      type: 'POST',
      url: 'index.php',
      data: {
        // Notice that this is the method name that
        // we wish to call on the server side.
        'method': 'getJsonTree'
      }
    }
  });
});

// Refreshing the tree view - Destroy and recreate
$('#btnRefreshTreeView').click(function() {
  var api = $('#fsTree').aciTree('api');
  api.unload(null, {
    success: function() {
      this.ajaxLoad(null);
      // Triggering the click handler of the Get Tree View button.
      // This will make the ajax call again and bind the tree...
      $('#btnGetTreeView').trigger('click');
      $currStatus.text('');
    }
  });
});

4. Event handling for the aciTree plugin

And finally a simple event handler for the aciTree that is triggered whenever a node in the tree is selected –

// ACI Tree - event handler.
$('#fsTree').on('acitree', function(event, aciApi, item, eventName, opt) {
  switch (eventName) {
    case 'focused':
    case 'selected':
      // Fired when an item in the tree is selected.
      if (item) {
        $currStatus.text('Selected - ' + item.context.innerText);
      }
  }
});

You can find the whole code here and a working copy of the project here.

Setting up my fresh Crunchbang installation

Update 2016-01-16

Development of Crunchbang has now stopped. There are a few community spin-offs available, Bunsen Labs and Crunchbang++. Although most of what’s been written here should be applicable to these distributions, it hasn’t been tested. I’m now using a netinst version of Debian at home with the i3 window manager, and Bunsen Labs on my office laptop. Both are working well.


For the past year and a half, I’ve been working primarily on Microsoft’s stack – C#.NET, ASP.NET Web Forms, HTML, CSS, JavaScript (jQuery primarily). My company recently started taking up projects on open source software such as PHP, WordPress and Android. This gave me an opportunity to shift to Linux again. I’ve always been fond of Linux. The ability to customize and fine tune your system to just the way you like it gives me a sense of freedom and power.

Last Friday, I installed Crunchbang. It is a Linux distribution derived from Debian. The purpose of this post is to outline the various steps I followed to get Crunchbang ready for use. I can then refer to this post whenever I’m setting up my system again, or helping someone else set up theirs.

Hardware Configuration

I’ll start of with my computer specifications first. This might help people with similar hardware configuration to find a solution to their problems.

NameConfiguration
ProcessorIntel i5-4570 CPU @ 3.20GHz
MotherboardGigabyte H87M-D3H
RAM6.00 GB RAM
Video CardMSI HD 7850 Hawk
Monitor(s)Philips 190VW (1440 X 900) Dell S2240L (1920 x 1080)

System Update

Once Crunchbang is installed and you boot up for the first time a handy script starts up that allows you to update your system and installed software. This script can be invoked later on as well by running cb-welcome command on the terminal.

Installing LAMP and Java

Follow the script and install Java and the LAMP stack. It is also possible to install – Git, SVN and drivers for printer.

Installing AMD Proprietary Driver

After the script has finished, it’s time to install the graphics driver.

I followed the manual method outlined in this post on the Crunchbang forums. I tried using smxi to do it for me, but I think it was having trouble disabling the default Radeon drivers. Follow the exact steps, and reboot whenever advised.

Setup dual monitors in AMD CCC

Okay, so driver installation is over. It’s time to set up dual monitors. By default, after you’ve installed Crunchbang on a system that has dual monitors and an AMD graphics card, the monitors will duplicate each other. Once you’ve installed the driver you can change that setting. Fire up the AMD Catalyst Control Center by running amdcccle command on the terminal.

Change the mode to extend the display to two monitors rather than duplicate the display –

Multiple Monitors in AMD CCC

Placing monitors in the correct order (left or right of each other) is as simple as dragging them into place. You can also change the resolution from this screen.

Another problem that people with DELL S2240L and AMD cards will have that the display on the monitor won’t re-size to fit the entire screen. The fix for that is available through CCC –

Dell S2240L Overscan Correction

Note that the CCC makes changes to the xorg.conf file in /etc/X11. If you don’t want to make these changes everytime you reinstall Crunchbang, just backup that file.

Installing Logitech Wireless Driver

I have a wireless Logitech keyboard. With the new motherboard the keyboard is not auto detected by Crunchbang. Installing the driver found here and then restarting resolves the issue.

Boot Error : platform-microcode : intel-ucode … (not found?)

If you are running new Intel hardware, the following error –

platform microcode: firmware: agent aborted loading intel-ucode/06-1a-05 (not found?)

seems to pop up during boot. It’s basically harmless, but can be fixed by installing intel-microcode using APT.

Un-install Software

gFTP
Transmission
Gnumeric
VLC Media Player
Abiword

Install Software

Following is a list of software I install after installing #!

Deluge

Torrent client

sudo apt-get install deluge

Clementine

Music player

sudo apt-get install clementine

Dropbox

Use existing #! script, under the Openbox menu, Networking tab.

MPlayer

Video player

sudo apt-get install mplayer

Then change add the following to the ~/.mplayer/config

#Volume softvol=1 softvol-max=400

This raises the max volume to 400%.

Artha

Dictionary

sudo apt-get install artha

Google Chrome

Use existing #! script, under the Openbox menu, Networking tab.

Flux

Monitor screen color manager

I know the above line, doesn’t make it sound very exciting, but you really should give flux a go.

  • Grab the binary from here. That’s the xflux daemon (command line, but for X-Windows).
  • Add the following line to Openbox autostart file to start xflux daemon on system startup.
# l – latitude, g - longitude
xflux -l 17.4 -g 78.5

Netbeans

Development IDE for PHP

Grab the installer from here

Code::Blocks

C / C++ Editor

Grab the .deb from here

OpenOffice

Grab the .deb installation files from here
Run the following commands one after the other –

sudo dpkg -i *.deb 
cd desktop-integration 
sudo dpkg -i *.deb``

Customize Startup and Openbox Menu

autostart.sh determines the applications to be run at start-up and menu.xml defines the layout of the Openbox menu.

Here is my current autostart.sh file and here is my menu.xml.

Customize Conky and Tint2

Conky is basically a system monitor software for the X Window System. It can be extend via plugins and can be customized to show things such as weather.

Tint2 is a task-bar designed to be simple and lightweight. Here’s my tint2 config file.

My Conky configuration can be found here. The result –

Conky Screenshot

That’s it. That’s all I do once Crunchbang has been installed. It took me about four hours hours, but with this post as a reference, next time I should be able to reduce that time to about an hour.

Crunchbang is wonderful distribution that is minimalist, fast, stable and extremely customizable. It runs very well on old and new hardware. They have a helpful and friendly community. So, if you are looking for a new Linux distribution to try out, do give Crunchbang a test drive.

  1. List of software that can be installed using APT on !#.