Tag: bash

Get your update against GNU Bash “SHELLSHOCK” vulnerability

Anoop C SLeave a comment

attackers-exploit-shellshock-bug-showcase_image-2-a-7361

This is a very important announcement from FSF [Free Software Foundation]. I would like to share with you, readers, about the unnoticed vulnerability inside Bash [Bourne Again SHell]. Let’s have a look at FSF’s statement on this particular issue.

“A major security vulnerability has been discovered in the free software shell GNU Bash. The most serious issues have already been fixed, and a complete fix is well underway. GNU/Linux distributions are working quickly to release updated packages for their users. All Bash users should upgrade immediately, and audit the list of remote network services running on their systems.”

The vulnerability affects from version 1.14 through 4.3 of GNU Bash. This particular issue is named as Bash Bug.

What if I don’t update?
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[Bash Script -1] For rotating two-dimensional matrix

Anoop C SLeave a comment

Image

#!/bin/bash

#Here we use the row major representation of a two-dimensional matrix.
#Array ‘x’ is the original matrix and  ‘r’ is the matrix after rotation.
#Matrix rotations in multiples of 90 degrees can be done by calling the rotate function repeatedly.

#perform clockwise-rotation by 90 degrees
rotate () {
t=(“$@”)
let i=0
while [ $i -lt $n ]
do
let j=0
while [ $j -lt $n ]
do
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Some useful tips while working under GNU Bash – part 2

Anoop C SLeave a comment

terminal-icon-512x512[1] Efficient use of command line history using !! and !
Double exclamation i.e, ‘!!’ represents the last run command on the bash. Here is an example :
$ uname -r
3.2.0-55-generic
$ !!
uname -r
3.2.0-55-generic

Now, let’s come to single exclamation i.e, ‘!’ . Unlike ‘!!’, through single exclamation ‘!’, we can access any previously run command that exists in
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