Packt is offering all of its eBooks and Videos at just $10 each for 10 days

Packt is celebrating 10 years anniversary and is celebrating that with offering all of its eBooks and Videos at just $10 each for 10 days.
http://bit.ly/1k5EUYD

How to Send Mail from the Command Line with Telnet

You can easily test your mail configuration from a linux server with telnet.

$ telnet rhel1 25
Trying 172.168.1.1...
Connected to rhel1.
Escape character is '^]'.
220 rhel1.localdomain ESMTP Postfix
<b>HELO rhel1</b>                        # Note that "HELO" is not a misspelled. It is the command for telnet services.
250-rhel1.localdomain
250-PIPELINING
250-SIZE 10240000
250-VRFY
250-ETRN
250-ENHANCEDSTATUSCODES
250-8BITMIME
250 DSN
<b>MAIL FROM: ivan@rhel2</b>
250 2.1.0 Ok
<b>RCPT TO: david@rhel1</b>
250 2.1.5 Ok
<b>DATA</b>
354 End data with <CR><LF>.<CR><LF>
<b>Subject: Subject goes here.</b>
<b>Body goes here.</b>
<b>.</b>                                # End body with '.' and Enter                            
250 2.0.0 Ok: queued as 5C3E5E12EA
                                 # Quite interactive mail session with ctrl + ']'
<b>quit</b>
221 2.0.0 Bye
Connection closed by foreign host.

For a more detail description, please see http://www.ehow.com/how_5209651_use-sendmail-command-line.html.

Server Comaparison between RHEL and Windows

An interesting comparison (in swedish) between RHEL server and Windows server.

Source:http://techworld.idg.se/2.2524/1.498006/windows-vs-linux---nu-avgors-kampen

How to Install KVM on Ubuntu 14.04 LTS (Trusty)

Prerequisite

Verify that you have enabled virtualization in BIOS. For detail see Virtualization with KVM on RHEL 6

Install

Install required packages.

$ sudo apt-get install qemu-kvm libvirt-bin bridge-utils virt-manager

Run

Now you ready to run virt-manager and install new virtual guests.

$ sudo virt-manager

If you are new to kvm, please read Virtualization with KVM on RHEL 6 for a detailed description.

Tweak Unity in Ubuntu 14.04

The preferred way to tweak the user interface (Unity) in Ubuntu 14.04 is via the unity-tweak-tool. You can also use ccsm - CompizConfig Settings Manager, but I would recommend to stick with the recommended unity-tweak-tool, since settings can be messed up, when manipulating settings with different tools.

To install:

$ sudo apt-get install unity-tweak-tool

And if you have got lost when configure, you can always get back to original configuration with:

$ unity-tweak-tool --reset-unity

Static Routes with RHEL 6

The new way to add static routes in RHEL 6 is

$ vi /etc/sysconfig/network-scripts/route-<interface>

ADDRESS0=X.X.X.X
NETMASK0=X.X.X.X
GATEWAY0=X.X.X.X

Or alternative via the old ip command style.

$ vi /etc/sysconfig/network-scripts/route-<interface>

X.X.X.X/Y via X.X.X.X dev <interface>

And to set the default gateway.

$ vi /etc/sysconfig/network
...
GATEWAY=X.X.X.X
...

How to Install Minecraft in Ubuntu 14.04

Kids go crazy over the swedish developed game Minecraft. Below is a link how to install it on Ubuntu 14.04.

http://ubuntuhandbook.org/index.php/2014/04/install-minecraft-in-ubuntu-14-04/

How to Merge Multiple PDF Files in Ubuntu

You can easily merge several pdf files into on file with 'pdftk - A handy tool for manipulating PDF'

Example how to merge file1.pdf and file2.pdf to mergedfile.pdf.

$ pdftk file1.pdf file2.pdf cat output mergedfile.pdf

Convert MP4 to MP3 on Ubuntu 14.04 Trusty

There is a program available on Ubuntu youtube-dl, that can download videos from youtube.com or other video platforms. But it stores the file in mp4, since it contains video. But sometimes you do not want the video and only the audio. To extract only the audio part, you can use the pacpl comamnd line tool.

pacpl --to mp3 -v -r- -bitrate 320 targetfile.mp4

Bash Programming Documentation in RHEL 6

I'm not a bash script guru, so I need documentation. Here I will show you how to get/install that for RHEL 6.

All the BASH documentation is available via the bash-doc RPM, but it is not located in the RHEL base channel (rhel-x86_64-server-6), but in the RHEL Server Optional channel (rhel-x86_64-server-optional-6).

To add or remove channels from the command line you use the rhn-channel.

rhn-channel --channel=rhel-x86_64-server-optional-6 --add --user=<RHNREG_USERNAME> --password=<RHNREG_PASSWORD>

Now you are ready to install the bash-doc package.

yum install bash-doc

And to list the installed files.

$ rpm -ql bash-doc
...
/usr/share/doc/bash-4.1.2/doc/bashref.pdf
...

And the most interesting file is the BASH Reference Manual, as highlighted above.