Managing a Linux server is built on being comfortable with the command line. Without a graphical interface, you can manage the entire system with a few dozen commands. This guide offers a practical reference of the most-used Linux server commands, grouped by function.
Related reading: Connecting to a server with SSH · KEYDAL hosting · Linux Server Administration Basics: SSH, Firewall, Cron, and Service Management
Viewing File Content and Searching
Reading configuration files, inspecting logs and searching text is an important part of daily administration.
cat file- prints the entire content of short files.less file- shows long files page by page, scrollable.tail -f /var/log/...- follows a log file live.grep "text" file- searches for text within a file.find /path -name "*.log"- finds files matching a pattern.
System and Resource Monitoring
To understand your server's health you need to monitor CPU, memory and disk usage. These commands are the starting point for troubleshooting.
| Command | Function |
|---|---|
top / htop | Live CPU, memory and process monitoring |
df -h | Fill level of disk partitions |
du -sh * | Folder sizes in the current directory |
free -h | RAM and swap usage |
uptime | Uptime and load average |
Process Management
You use these commands to see running programs, terminate a stuck process or check a service's status: ps aux lists all processes, kill PID terminates a process, and systemctl status service shows a service's state. We will cover service management in depth in a separate guide.
Networking and Connection Commands
ip a- shows network interfaces and IP addresses.ping domain- tests reachability of a target.curl -I https://site- fetches a URL's HTTP response headers.ss -tulpn- lists listening ports and services.
Permission and Package Commands
System-level operations require administrator privileges; you prefix the command with sudo. To install software you use your distribution's package manager: apt on Debian/Ubuntu, dnf on RHEL/Rocky. We will examine file permissions and package management in detail in later articles of this series.
Frequently Asked Questions
Do I need to memorize all these commands?
No. For daily use 15-20 commands are enough; you learn the rest from man pages as needed. They become permanent with practice.
How do I view command history?
The history command lists previous commands. You can scroll recent commands with the up arrow and search history with Ctrl+R.