While working with MySQL databases, it is often required to find out the total number of rows in some table. There are many different ways to count the table rows in MySQL, but as the performance always matters, the fastest way is the most preferable. Below you will find the best and the fastest way […]
MySQL: Table Size
Sometimes it is required to find out the size of a table in MySQL database. For example, if it is needed to perform an optimization and you analyze if some tables have become too large and it is time to tweak them somehow. In this short note i will show the SQL query that gets […]
MySQL: Checksum Table
Sometimes it is required to compare two tables to check if they are the same or not. For this you can calculate and compare the checksums of each table, using the CHECKSUM TABLE command in MySQL. This command is especially useful if you’re using MySQL replication and want to ensure that master and slave are […]
Show Git Branch In Terminal – Command Prompt
When you are working inside a Git repository it is important to realize what is the currently checked out Git branch. You can make it easier to track where you are, by showing the name of the current Git branch in the terminal (command prompt). In the almost any Linux distribution, including Ubuntu and CentOS, […]
MySQL: Show Users, Privileges and Passwords
In this article i will show how to list MySQL users, their passwords and granted privileges from the command-line prompt. MySQL account consists of two components: user and host. This allows the same user to use different MySQL accounts with different privileges, depending on which host they are connecting from. In the Host field, besides […]
/etc/shadow – HowTo: Generate Password Hash in Linux
Linux stores users’ encrypted passwords, as well as other security information, such as account or password expiration values, in the /etc/shadow file. Someday you may need to edit the /etc/shadow file manually to set or change ones password.
HowTo: Upgrade Salt-Minions and Don’t Lose Them
If you try to upgrade salt-minions from the salt-master, in most cases salt-master would probably lose access to the minions. If the access is lost, you would have to log in to each host and restart the salt-minion service manually to make it communicate back with the salt-master. This problem is caused by the salt-minion […]
Salt – Download a File With Unknown Source_Hash
In salt, there is a useful file.managed state that can download files over HTTP/HTTPS and save them on the target system. Unfortunately for the moment it is not possible to download a file using salt in an normal way without knowing the file’s hash. If you try to download a file using salt state without […]
Git – The Basic Workflow
Git is a version control system (VCS) that allows to keep track of the changes made to a project over time. Git records the changes you make to a project, stores those changes and then allows you to reference them as needed. From the following article you will learn what does the basic Git workflow […]
HowTo: Merge PDF Files – Linux Command Line
Sometimes it is required to merge several PDF files into a one PDF file. In Linux we can easily join multiple PDF files using the command line utility called convert that is a part of ImageMagick software suite. From this article you will learn how to merge entire PDF files into one PDF file or […]