Useful Yum commands

Few useful yum commands

1. yum list installed - Gives a list of already installed packages
2. yum history list   - Gives a list yum installs. Note that one can install multiple packages and their dependencies in a single invocation. Example, yum install docker-ce, docker-ce-cli
3. yum history info   - Gives the details of yum invocation for each of the historical entry above.
4. /var/log/yum.log - also contains log of yum installs
5. yum list docker-ce --showduplicates | sort -r  - Shows all the versions that are present for docker and sorts them.

To find difference in packages between installs -

• Before installation - 

rpm -qa --qf '%{NAME}.%{ARCH}\n' | sort > old-installed-rpms.txt

• After installation - 

rpm -qa --qf '%{NAME}.%{ARCH}\n' | sort > new-installed-rpms.txt

• Diff - 

diff old-installed-rpms.txt new-installed-rpms.txt | grep '^<'

Remote Interview Tools, Online Java Compilers & Cloud hosted IDE

Very good for Interviews (Basic stuff available for free, advanced features on purchase)

• CoderPad
• CodePad 

Basic Online Compilers (Free or Ad-supported)

• IdeOne
• Browxy 
• RexTester 

Cloud Hosted IDE (Paid services only)

• Cloud9 - Supported Languages
• Nitrous - Java on Nitrous
• Koding - Features
• Sourcelair - Supported Languages
• Bonus - Crisp comparison of Cloud hosted IDE (Published Date : Aug 2014. So, it may not cover any recent updates)

Modify Windows Control Panel Settings from command-line

I recently discovered that many Control Panel settings in windows can be opened from command-line. The article from Microsoft How to run Control Panel tools by typing a command explains.

Windows Command line shortcut to set Environment Variables

In order to invoke the System window and later set the Environment variables, the below command-line could be handy. It will avoid some mouse-clicks :)

C:\windows\system32>control.exe sysdm.cpl,System,3

The above command can also be saved into a bat file and placed conveniently on Windows Desktop.

Useful websites

25 Lifehack websites

101 Useful websites

e-Learning related websites (MOOC or similar)

Coursera
Khan Academy
Udacity
edX
Academic Earth
Duo Lingo - Learn languages
MIT Open Courseware
codecademy - coding languages
Learn Street - coding languages
Udemy - Coding, Design etc

New Think Tank - Excellent collection of video tutorials for Java, OOPS, Algorithms, UML etc

MOOC List - A collection of MOOC (Massive Open Online Course) -
piazza - Learning University collaboration -
Cosmo Learning - Online Videos -
Learn Now Online - Online Videos for Developer, Manager etc (MS .Net, Java, PMP, MS Office etc)

tar destination directory

tar by default extract's to the current directory, if that needs to be changed, it can be done by using below -

[rakesh@host2] tar zxvf source.tar -C /your/dest/dir/to/extract