The substitution option is one of the most useful options of a sed command. In particular, it allows to search a text file for lines that contain particular string (SEARCH_STRING), word or match some regular expression and replace all occurrences of such lines with some REPLACEMENT_LINE. To replace the whole line using sed, it is […]
MySQL: Database Size
It is often required to get the size of a database in MySQL to understand how much disk space does it need. It is especially useful to check the size of a database if you prepare to migrate it somewhere or going to setup database backup and it needs to choose the storage capacity. In […]
Tor Browser for Linux – How To Download and Install
Tor Browser is widely used for anonymous web-surfing and protection against traffic analysis. It is also can help to bypass Internet filters and access blocked websites. This is a simple step by step guide that covers the installation process of the Tor Browser on such Linux systems as Ubuntu, Kali Linux, Debian, Linux Mint, Fedora […]
MySQL: Count Rows in Table – The Fastest Way
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 […]