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Hotlinking is the use of a linked object, often an image, from one site into a web page belonging to a second site. The second site is said to have an inline link to the site where the object is located.
It is always recommended to enable hotlinking of images, else others use just links to [...]

Kernel 
 It makes sure that all processes in the system works fine
Rebuilding

It is done to optimize the kernel to suit our requirements as well as make it more secure from internet attacks
 Steps

1. Determining the current hardware 
 This is required during configuration process to enable hardwares that our new kernel has to support.
Commands used for the same are:
 
 

/sbin/lspci 
cat [...]

To find the processor type and details
Get the Processor details:

cat /proc/cpuinfo

Find whether the processor is 32 or 64 bit:

 getconf LONG_BIT

Find the architecture:

uname -i

 Ping Requests use ICMP protocols. This is enabled/disabled using sysctl values.
To Disable Ping:
 
echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all
 
To Enable Ping:
 
echo 0 > /proc/sys/net/ipv4/icmp_echo_ignore_all

 Scenario
To log into “Server A” from “Server B” without using passwords. Users for both the server will be “root”
Process

 Login to “Server B” as root user and generate key for the root user. No need to enter any passphrase while generating this key.

ssh-keygen -t rsa
 
Once the key is generated, copy the contents of “Server B” /root/.ssh/id_rsa.pub [...]

“find” is a versatile tool which can be used to locate files and directories satisfying different user criteria. But the sheer number of options for this command line tool makes it at the same time both powerful and encumbering for the user. 
Here are a few combinations which one can use to get useful results using find [...]

You can disable/enable safe_mode either using .htaccess, php.ini or httpd.conf file. Selecting the right way depends on your php-apache configuration.
If php is compiled as a dso module for apache, you will have to use .htaccess method
If php-apache relationship is CGI, then php.ini file is used to disable safe_mode value
 If none of the above works, contact [...]

Purpose
Unless the ftp users are limited to their home directories, they will able to access all files & folders on the server .
How to
Below you may see how this can done to 3 of the ftp servers used in common.
Pro-ftpd
vsftpd
pure-ftpd
Pure-ftpd
vi  /etc/pure-ftpd.conf
And change the following line
ChrootEveryone=YES
pro-ftpd
vi /etc/proftpd.conf
DefaultRoot ~
Vsftpd
vi /etc/vsftpd.conf
chroot_local_user=YES

ImageMagick® is a software suite to create, edit, and compose bitmap images. It can read, convert and write images in a variety of formats (over 100) including DPX, EXR, GIF, JPEG, JPEG-2000, PDF, PhotoCD, PNG, Postscript, SVG, and TIFF. Use ImageMagick to translate, flip, mirror, rotate, scale, shear and transform images, adjust image colors, apply various special effects, [...]

This is an awasome feature of hylafax. User can send fax using email applications. Ex: riyesh@23656237.fax
We need to add some simple scipts to activate this feature.By defult hylafax will not decode the attachments.So you need to edit /etc/hylafax/hyla.conf.
specify mime type directory location in /etc/hylafax/hyla.conf
add the following line
MIMEConverters: /var/spool/hylafax/mimetype
Then create the converting scripts under /var/spool/hylafax/mimetype
mkdir /var/spool/hylafax/mimetype
you [...]