Webkoof

Highlight terms while tailing a log

Vikash — Thu, 05 Jan 2012 05:54:14 +0000

Sometimes I want to keep tailing a log and look for a term – for example if you are an e-commerce platform then you may like to keep a running tail somewhere while keeping en eye on “checkout” page. Following code snippet will highlight the term: tail -f /var/log/apache2/access.log | perl -p -e 's/(checkout)/\033[46;1m$1\033[0m/g;' You [...]

Setup IP to city/country detection using geoIP in php

Vikash — Mon, 07 Nov 2011 11:58:11 +0000

Following instructions are for apache on ubuntu. # Install GeoIP module for php5 sudo apt-get install php5-geoip # Restart Apache sudo /etc/init.d/apache2 restart # Now, the country wide data is automatically installed with geoIP module. # But, if we want to have it at city level - we need to download the data. [...]

My Experiments with AWS – 3 : lamp server, Elastic IP, DNS for ec2

Vikash — Mon, 01 Aug 2011 18:04:14 +0000

Now that we can connect to the ec2 instance – we want to setup a basic website. I use ubuntu AMI – so, following instructions are for ubuntu. Similar instructions for other platforms can be ported as well. Installing LAMP Server # install Apache , PHP and MySql as a package sudo tasksel install lamp-server [...]

My Experiments with AWS – 2 : Connect to EC2 instance

Vikash — Mon, 01 Aug 2011 10:42:49 +0000

In order to connect with an ec2 instance there are three prime prerequisites: The key file (.pem extension) created while launching an EC2 instance in AWS. Port 22 of the instance is open while launching the instance. Know the public DNS of your EC2 instance. Key File: Read Basics of AWS and how to launch [...]

My Experiments with AWS – 1 : Basics of Amazon Web Services

Vikash — Sun, 31 Jul 2011 18:21:01 +0000

I have been with dreamhost for 1400 days before I opted to move everything to AWS. I did not had any particular problem with dreamhost. They are good and their support is even better but I wanted to explore AWS, move away from my comfort zone of hosted services, get my hands dirty and learn [...]

Basic regex reference

Vikash — Thu, 21 Jul 2011 15:47:16 +0000

Operator Purpose . (period) Match any single character ^ (caret) Match the empty string that occurs at the beginning of a line or string $ (dollar sign) Match the empty string that occurs at the end of a line A Match an uppercase letter A a Match a lowercase letter a \d Match any single [...]

To be a good web developer

Vikash — Wed, 20 Jul 2011 13:14:49 +0000

Be a good programmer first. (Point 2 to 14) Understand the pointers, memory allocation and all those low level ‘outdated’ things. (Yes, even when you program in Java) Learn the sorting alogrithms – You probably never going to write one, as your language has a built-in function for the job. But, Do it and understand [...]

How to write a tiny URL service using Redis, PHP and Apache

Vikash — Wed, 22 Dec 2010 18:25:00 +0000

There are so many tiny URL services out there. But, sometimes using those may not be suitable for your particular purpose for some reason. I faced a similar situation and came out with a decent solution using Redis (Thanks to @antirez for this brilliant key-value store), PHP and Apache. I used Predis, PHP client library [...]

Deny directory listing using .htaccess

Vikash — Wed, 16 Dec 2009 07:45:08 +0000

When you do not have an index.html (or index.php) in your folder, then people can see the listing of all the files by typing the URL of that folder. So, if the server does not deny it by default, an user can see the content of the folder. We can use htaccess file to prevent [...]

Color image on mouseover of a gray one

Vikash — Mon, 05 Oct 2009 07:55:57 +0000

The idea of this approach is following 1. Take two identical images: one colored and one grayscale. 2. Position them on exact same position. Grayscale image on top using CSS positioning and z-index. <img src="gray.png" id="gray" style=" position: absolute; top: 20px; left: 20px; z-index: 100"> <img src="color.png" id="color" style=" position: absolute; top: 20px; left: 20px; [...]