Mohsin Sumar

PHP / MySQL eCards tutorial

Mohsin Sumar — Thu, 22 Jul 2010 23:04:46 +0000

In 2003, I wrote a tutorial on how to build your own eCards service using PHP/MySQL. It was written and published on Flash-dB Forum. If you have any queries, please direct them to Flash dB - Flash eCards Forum.

The bad news is that the tutorial went off-air and I am unable to find it. If you happen to have a copy, please email it to me and if I do manage to find it, I will make a point to update this post.

However, the good news is that I have the zip archive with the scripts. Click on the link below to download.

Download PHP / MySQL eCards Tutorial

You do not get great handwriting if you do not start scribbling

Mohsin Sumar — Tue, 01 Jun 2010 21:02:22 +0000

I came up with my first original quote in one of my email correspondences today, and I would like to share it with you.

"You do not get great handwriting if you do not start scribbling"
- By Mohsin Sumar

Sponsors of Veterani Sports Club – Gezaulole

Mohsin Sumar — Sun, 30 May 2010 10:51:01 +0000

Mohsin handing T-Shirt of "Extreme #1" to the Goalkeeper of Veterani Sports Club - Gezaulole, Kigamboni, Dar es Salaam on 21st May 2010.

Earlier this month, on the 21st May 2010 - Extreme Web Technologies sponsored a local football club called Veterani Sports Club in Gezaulole, Kigamboni, Dar es Salaam.

We sponsored new jerseys, shirts, shorts, socks, goalkeepers gloves, referee uniforms, accessories and most important of all - footballs.

You can see me handing over T-Shirt of "EXTREME #1" in the photo on the right.

Click here to see more photos of this event in Extreme Web Technologies Facebook Page.

Hibernate does not work anymore in Microsoft Vista

Mohsin Sumar — Sun, 14 Mar 2010 23:19:05 +0000

It's been a while since I blogged last, and even longer since I cleaned and free up some disk space on my laptop. While moving and deleting data last week, I used disk cleanup utility. I cleared couple of GBs using this utility, including Hibernation File Cleaner. Obviously, I had no idea what this would do to my laptops' power settings and realized it after a few days that my laptop doesn't hibernate any more and goes to sleep.

After quite sometime trying to fix this, I stumbled across the following knowledge base article on Microsoft Support site: http://support.microsoft.com/kb/929658

The fix is really simple; all you need to do is log in as Administrator and run the following command:-

powercfg /hibernate on

You'll now be able to hibernate again. I'm going to do just that right now!

Securing PHP application from malicious scripts

Mohsin Sumar — Thu, 26 Nov 2009 22:35:48 +0000

If you've stumbled across this post, then you've recently become a victim of the most famous way of uploading a malicious script to a website - PHP file uploads.

Many websites and web applications that are developed using PHP & MySQL allow users to upload files, photos and documents to the server. Normally, the upload script receives the files and moves (or writes) it to a directory (folder) with write permissions. If you are on Linux, then this would mean that your folder CHMOD value is 0777.

The Problem
The changing of CHMOD value to 0777 practically allows anyone in the WORLD to write to your folder and is therefore not recommended. However, many a times we are left with no option but to do so - depending on the servers' environment.

How can this be a problem?
This allows attackers to upload upload a malicious PHP script to your directory, which they will then execute by accessing it. This script could either be a mass-mailing script or a malicious script to gain access to your account (or web server).

The Solution
It is said that prevention is better than cure - and therefore, it is important to prevent these scripts from being executed by the server. This can very simply be done by adding a few lines of code to your .htaccess file. If your directory is supposed to hold photo files only, then the following code is recommended to prevent scripts from being executed.

It is also important to disable directory listing on these folders.

# Disable Directory Listing
Options All -Indexes

# Allow access to these file extensions only

 Order Allow,Deny
 Deny from all

The above will add an extra layer of security to your web application.

How do I extract a tar file?

Mohsin Sumar — Mon, 23 Nov 2009 21:31:47 +0000

Using the following command in SSH, you will be able to extract files from your tar file.

tar -xf file.tar

How to tar a file using SSH?

Mohsin Sumar — Sun, 22 Nov 2009 17:23:13 +0000

Use the following command if you want to create a tar and compress a file (or folder).

tar -czf /path/to/save/file.tar folder_or_file_name

The options used in the above command are outlined below for your understanding.

-c = create
-z = compress a file
-f = use the file mentioned instead of tape drive

A man should look for what is, and not for what he thinks should be.

Mohsin Sumar — Sun, 15 Nov 2009 21:32:44 +0000

"A man should look for what is, and not for what he thinks should be."
- Albert Einstein

SSH ls pagewise or limit long output

Mohsin Sumar — Sat, 14 Nov 2009 12:26:31 +0000

If your SSH ls command output is really long, and cannot be viewed on screen - you can use the following command to part of it with a more command to continue down the list.

ls [options here] | more

Example:-

ls -l | more

My 22nd Birthday

Mohsin Sumar — Sun, 08 Nov 2009 07:00:18 +0000

I was born around this time around 22 years ago.

Thank you to everybody for your thoughtful birthday wishes via phone call, text message, email and facebook!