fsck Messages, Meaning and Solutions

fsck message can be cryptic and many times it is difficult to understand it is great challenge to decide about the response to provide for fsck prompts.

This article describes  the fsck error messages and possible action that can be performed  during each phase of fsck.  If you are looking for fsck and related information, you can find it in this article fsck – Check & Repair Unix and Linux File Systems

These are the phases and detailed errors, messages  with their meaning

Top 10 Bash Programming Guides, Reference & Tools

Bash is a Unix/Linux  command interpreter (shell). Bash is the Bourne Again SHell created as part of  GNU Project.  Bash is an Bourne  shell compatible shell that incorporates useful features from the Korn shell (ksh) and C shell (csh). It offers functional improvements over Bourne shell  for both programming and interactive use. In addition, most Bourne shell scripts can be run by Bash without modification. Bash  is intended to conform to the IEEE POSIX P1003.2/ISO 9945.2 Shell and Tools standard.

Bash was originally written by Brian Fox of the Free Software Foundation. The current developer and maintainer is Chet Ramey of Case Western Reserve University.

The improvements offered by Bash include:

  • Command line editing
  • Unlimited size command history
  • Job Control
  • Shell Functions and Aliases
  • Indexed arrays of unlimited size
  • Integer arithmetic in any base from two to sixty-four

Here are the top 10 Bash Programming Guides, Reference  & Tools

Agile and Manual Testing in 2018 and Beyond


The year 2017 was an exciting one for the software industry wherein many companies embraced Agile, DevOps, Scrum, and Continuous delivery models. With these approaches, software is now being rapidly developed and is released in the market a lot quicker than before. Most importantly, the quality of released software is more sustained and gaining the approval of both the stakeholder and the consumer. In fact, research by Technavio expects the global software testing market to grow steadily to around 14% in the coming years. The same study also reports that agile testing services are primarily responsible for the software growth in the market.

However, will these trends continue in 2018? What about the role of manual testers? We all know that software developers prefer software automation testing more because of its reliability, cost-effectiveness, and its ability to save time. But how will manual testers adopt to the growing changes in the future? 

How to Remove ^M in Linux & Unix

Control M ( ^M)  characters are introduced when you use  lines of text from a windows computer to  Linux or Unix machine.  Most common reasons are when you directly copy a file from a windows system or submit form data copied and pasted from a windows machine.

Detecting ^M characters

^M is non printable character and often becomes difficult to find, in order to see if your file contains any non printable character use the cat command with -v option

$cat -v filename

Methods to remove ^M

In all these method , real secret is not to type ^M using keyboard but rather typing in control key sequence to get the ^M control character.

Bash Positional Parameters

Shell has several special positional parameters which can be referenced but can not be assigned. These are used to process command line arguments in a shell script, to get process status, exit status and options flag.

These positional parameters can be assigned to a variable and values can be used for further processing.

 $0 , $1 $2 $3 … parameters

These are special parameters and and has specific meaning according to the number.  These parameters are useful if you want to validate executing file name and do the processing based on the arguments.

$0 : Shell argument 0, It expands into bash script file name or bash shell.

$1 $2 $3 …   : Shell argument number : Used to get the specific argument from the script.

for example let’s create & execute the test script with some parameters :

‘Amazon go’ – No Checkout Store Opens in Seattle

Amazon Go is a new kind of store with no checkout required,amazon go store

Use app to enter the store, and after that you don’t need it to shop. Browse and shop like you would at any other store and once you’re done you can simply walk out without having to stand in a checkout line.

Amazon Go store opening on Monday in Seattle is about 1,800 square feet store, located at 2131 7th Ave, Seattle, WA, opening from 7AM—9PM open Monday through Friday. The store will offer ready-to-eat breakfast, lunch, dinner, and snack options made by chefs and favorite local kitchens and bakeries. Grocery essentials ranges from bread and milk to artisan cheeses and locally made chocolates. There are Amazon Meal Kits to get the meal ready in 30 minutes!

Although there is no human involvement in checkout a lot of technology in use at the backend, the same types of technologies used in self-driving cars like computer vision, sensor fusion, and deep learning.

Here is a video to explain shopping experience at amazon go store.

DNS Sinkhole Setup : Your defense against Bot net controllers

According to statistics published in csoonline.com cyber crimes damages will hit 6 trillion by 2021 and 6 billion people target ( 75% of projected 8 billion population).  As the access to network is increasing,  hacking and committing cyber crime has become as easy as sending an email with malware link and its clicking by unsuspecting victims.

A botnet consists of a  number of  compromised hosts  controlled by botnet controller managed by third parties .  Bot net constitutes a major security threat and used to deploy malware, steal sensitive data, orchestrate DDoS attack.  Once systems inside a network are compromised by installing malware it becomes very difficult to detect as the theft of data and sources of DDoS is orchestrated from within the network.

DNS sink hole is a process to identify the bot net master hosting malware software servers and assign the dns record of these hosts to localhost, non-existing or unused ip address . A  valid ip is not returned for these host resolution and the infected host never connects to the bot net master server.

In order to understand how DNS Sink hole work we need to understand the bot net structure and its organization.

 How a bot network is organized and activated ?

The initial part involves getting access to inside corporate network.  This can be achieved in many ways like using brute force method to crack the passwords and encrypted data and other approach is rather simple, involving sending a link in email and betting on the chances that some users will click the link and deploy malware on their computers.

Global Enterprise Mobility Trends

The landscape of enterprise mobility has seen numerous exciting developments that continue to shape the industry towards sustainable growth on a global scale. More and more organizations are viewing enterprise mobility as a priority rather than a mere project. In fact, recent statistics indicate that 71% of enterprise across the world regard mobility as a top priority and the market is anticipated to reach a valuation of US$510.39 billion by the end of 2022.

find command : 14 Ways to find files in Unix and Linux

find command is one of the important command in Unix and Linux used to locate the program, text,  data , log config files for execution, viewing ,  editing  renaming deleting etc. etc.

find command can find files based on many file attributes besides just the file name and here are the fifteen file  attributes which you can use to find a file or files and here are 14 ways to find files in your unix and linux system.

KRACK – Key Reinstallation Attacks on WPA2 Protocol


KRACK is a security flaw with WPA2  security and it allows to  compromise wireless WPA security  by forcing nonce reuse .

This is not an issue related to passwords but the protocol used by WPA and impacts pretty much all devices which uses wi-fi connection like phone, computers, wi-fi routers are impacted.

Red Hat 7.x Installation : Step by Step Guide

Installation and Configuration of RHEL 7.x
Learn about Installation and initial configuration of Red Hat Enterprise Linux, RHEL 7.3
For this Linux step by step installation guide we will use RHEL 7.3  64Bit iso image, the installation procedure is same for all RHEL 7.x releases in case you want to use a different RHEL version to install.

Here are the 10 Steps to Install RHEL 7.x distribution.

Linux PIE/stack corruption (CVE-2017-1000253) Bug and Security Vulnerability

About CVE-2017-1000253 Bug:

This issue is related to the Linux kernel loaded Executable and Linkable Format (ELF) executables. If an ELF application was built as Position Independent Executable (PIE), the loader can allow part of that application’s data segment to map over the memory area reserved for its stack.
It  can cause memory corruption and may allow an unprivileged local user to gain privileged access using Set owner User ID (SUID) or privileged flawed PIE binary.

Ideas for Choosing the Perfect Writer’s Laptop

In the modern era, a computer – especially laptop – is the essential tool for aspiring writers. Indeed,writer with pen you probably don’t lay your hands on a typewriter anymore unless you are a very old school person. The modern laptops are much better tools for those who have something to say and want to put in on paper or Internet. Me, being some kind of a writer as well, have been using ASUS ZenBook for a couple of years. It is a good writer’s notebook however not the only successful choice. In this article, I will point out some things important for a writer on a laptop hunt.

netstat – 10 Most common usage with examples

netstat is a command line utility in Unix, Linux and Unix like systems to show information about

  • network connections,
  • routing tables,
  • interface statistics,
  • mas-querade connections
  • multicast memberships

By default, netstat displays a list of open sockets of all configured address families , tcp , udp etc.
netstat provide very extensive network details and here are the top netstat usage with different options to get you the just the information you need.

How to Build a Winning Business Model in Enterprise Mobility

Strategy, business models, and tactics are often used interchangeably but they differ slightly in their actual meaning. Business model is the means of identifying a solution’s key offerings that will make customers pay for the product/service.

Business model is defined at the outset, when the enterprise mobility solutions are discussing a potential application idea. It is crucial to get all aspects of the business model right, and the ambiguities (if any) listed and categorized as ‘needed to be addressed before development’ or ‘can be expounded on later’.