Search Results for: Linux

Every bot on the internet knows that SSH lives on port 22. It’s the first door they knock on. Within minutes of spinning up a fresh Linux server, you’ll see login attempts from IPs you’ve never heard of, hammering away at the default SSH port number with dictionary attacks. The logs fill up fast. Changing

Every Linux process inherits a set of environment variables from its parent. These key-value pairs control how shells behave, where programs look for executables, and which configuration a running application picks up. Get them wrong and your deployment breaks at 2 AM. Get them right and you’ve got a clean, portable system config that travels

You’ve got a backup script. It works when you run it by hand. Now you need it to run at 2 AM every night without you babysitting the terminal. That’s where cron comes in, and getting the crontab syntax right is the difference between a script that fires on schedule and one that silently does

You’ve downloaded a .zip file to your server. Now what? On most Linux systems, double-clicking isn’t an option. The unzip command is how you crack open zip archives from the terminal, and unlike tar or gzip, it doesn’t come pre-installed on every distro. That distinction matters. Plenty of sysadmins SSH into a fresh VPS, type

Every sysadmin hits the same wall eventually: you’ve got 400 config files, one wrong IP address in all of them, and exactly zero interest in opening each one by hand. That’s where the sed command earns its keep. The Linux sed command (short for stream editor) lets you find, replace, insert, and delete text in

Master the Linux dig command for DNS lookups. Learn syntax, options, and examples to query DNS records and troubleshoot network issues.

Learn how to use the Linux grep command to search text patterns in files. Tutorial covers syntax, options, regex, and practical examples.

Master Linux process management. Learn to find PIDs and use kill, pkill, and killall commands with SIGTERM or SIGKILL to safely terminate unresponsive tasks.

Master the Linux time command to measure process duration and CPU usage. Compare Bash built-ins vs. /usr/bin/time sys metrics.