Linux Internal Variables

What are they? They are builtin variables which hold information about the environment, the users and the system. There are two main types; shell (bash) and environmental. The scope of each is different. Shell variables are specific to the running shell and are not shared within other shells. On the

git 1.8.x on CentOS

At the moment this is not on EPEL & CentOS repo, you'll have to compile from source. Get the desired version: http://code.google.com/p/git-core/downloads/list tar -xzvf ./git-1.8.x.tar.gz cd ./git-1.8.x ./configure make && make install

chmod directories and files separately

If you are looking to chmod directories and files separately, the find command can be of great help. Take a look at these examples: For Directories: find . -type d -exec chmod -v 775 {} \; For Files: find . -type f -exec chmod -v 664 {} \;

MySQL High Load / Other Issues - Leap second bug

After struggling with a sever that was acting up, i did some investigating and found it to be related to a recent leap second that was added on June 30th. On Saturday midnight Greenwich Mean Time (GMT), an extra second was added to the Universal Coordinated Time (UTC). According to

Delete a single iptables rule

This will list all of your rules, plus their chain name and number: iptables -vnL --line-numbers Example: 10 14 898 ACCEPT tcp -- * * 0.0.0.0/0 0.0.0.0/0 state NEW tcp dpt:139 11 54 3200 ACCEPT tcp -- * * 0.0.0.0/0 0.