The usual ps -ef or ps aux commands in Linux show the start time of the processes that have been started today. For the older processes they show the start date or the start year only, but not the start time. Don’t worry! The start time of the long-running processes in Linux is not lost […]
Linux: Compress PDF – Reduce PDF Size
A scanned document saved as PDF can be too large, that is not always good. For example, the large size of a PDF file won’t permit to send it by email because of the probable limitation on the maximum size of attachments. In Linux you can compress a PDF file from the command line without […]
HowTo: Split PDF File – Linux Command Line
Sometimes it is required to extract some pages from a PDF file and save them as another PDF document. In Linux we can easily split PDF documents by pages using the command line utility called pdftk. From this article you will learn how to extract individual pages or a range of pages from a PDF […]
SED – Find and Replace a String in a File
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, […]