A Tip A Day

• ATAD #24 – Conflicker is out there and rampant
  Malicious code that was recently classified as a worm, surfaced in October 2008 and exploits  MS08-067 vulnerability in the Microsoft Windows family Operating System (surprise surprise !!). The worm is known by various names Downup, Downadup,  Kido, and the most popular being Conficker. Conflicker has gone through various stages of development that make it h […]
  vinaydeep
• ATAD #23 – Pinhole camera
  A pinhole camera works on a simple principle where light enters a small hole to produce an image on the film/sensor. This image is usually sharp, but since only a small amount of light is entering the pinhole, longer exposure times would be required. A pinhole can never replace your camera lens, but such a [...]
  vinaydeep
• ATAD #22 – File Archives on Linux
  The two main formats for file archiving are tar and cpio. Both a used in tandem with compression utilities like the gzip and bzip. The archive formats were initially used for tape and other sequential access devices for backup purposes, it is now commonly used to collate collections of files into one larger file, for [...]
  vinaydeep
• ATAD #21 – Linux process priority range
  The Linux kernel implements two separate priority ranges. The first is the nice value, a number from –20 to 19 with a default of zero. Larger nice values correspond to a lower priority (you are being nice to the other processes on the system). Processes with a lower nice value (higher priority) run before processes with [...]
  vinaydeep
• ATAD #20 – Adding a linebreak in a wordpress post
  The wordpress wysiwug editor seems to remove the tag from the posts and prevents me from adding line breaks to format posts better. I found this piece of code that can be used to induce a linebreak in the wordpress post. . . Source [ via xarj ] __tipped__
  vinaydeep
• ATAD #19 – Linux login program
  The login program is used when signing onto a system. It can also be used to switch from one user to another at any time (most modern shells have support for this feature built into them, however). If an argument is not given, login prompts for the username. If the user is not root, and if /etc/nologin [...]
  vinaydeep
• ATAD #18 – Unix Standardization
  Software is probably the fastest thing that undergoes change, and its standardization is an important method for both software development and maintenance. Since its development in 1969, Unix has undergone a lot of changes and has evolved over the years. Here are a few of the efforts towards standardizing Unix. Probably the first step was in 1980 [...]
  vinaydeep
• ATAD #17 – I/O interface
  Communication between the processor and other devices are enabled by an I/O interface, and the Front Side Bus (FSB) is the data transfer bus that carries information between the CPU and the Northbridge (memory controller hub) of the Motherboard. The I/O interface must have atleast the following features Have necessary logic to interpret the device address […]
  vinaydeep
• ATAD #16 – escape sequence in bash
  Certain characters are processed by the shell, and can be escaped (\) to tell the shell to interpret that literally. Of note are the characters '$', '`', '\', and '"' echo "Hello Word"          #output: Hello Word echo "\"Hello World\""     #output: "Hello World" With certa […]
  vinaydeep
• ATAD #15 – Beyond the CPU clock speed
  In completing a task the computer splits each instruction into a series of independent steps. The computer that driven by a clock will process an instruction at a time and proceed to the next one in the instruction pipeline when the next clock signal arrives. So naturally, faster the clock speed, the instructions waiting in [...]
  vinaydeep