<p>If you’re a DevOps engineer, <strong>Linux is your playground</strong>. From managing servers to debugging containers, the command line is where most of the action happens. While there are hundreds of Linux commands, a handful of them form the backbone of daily DevOps tasks.</p><p>Here’s a curated list of the <strong>Top 20 Linux commands every DevOps engineer should master</strong>, along with why they matter and examples.</p><h2>1. <code>pwd</code> – Print Working Directory</h2><p>Quickly shows where you are in the filesystem.</p><pre><code class="language-bash">pwd
# Output: /home/ubuntu
</code></pre><p>🔹 Useful for navigating large infrastructure scripts or container directories.</p><h2>2. <code>ls</code> – List Files</h2><p>Displays files and directories with details.</p><pre><code class="language-bash">ls -l
ls -la
</code></pre><p>🔹 Helps inspect deployment directories, logs, or mounted volumes.</p><h2>3. <code>cd</code> – Change Directory</h2><p>Move around the filesystem.</p><pre><code class="language-bash">cd /var/log
</code></pre><p>🔹 Essential when exploring logs or configuration folders.</p><h2>4. <code>cat</code> – View File Contents</h2><p>Quickly dump file content to the terminal.</p><pre><code class="language-bash">cat /etc/os-release
</code></pre><p>🔹 Handy for checking configs without opening an editor.</p><h2>5. <code>less</code> – Scroll Through Files</h2><p>View long files with scroll/navigation support.</p><pre><code class="language-bash">less /var/log/syslog
</code></pre><p>🔹 Great for investigating server or CI/CD pipeline logs.</p><h2>6. <code>tail</code> – Stream Logs</h2><p>View the last lines of a file; <code>-f</code> follows changes.</p><pre><code class="language-bash">tail -f /var/log/nginx/access.log
</code></pre><p>🔹 Critical for live log monitoring in production.</p><h2>7. <code>head</code> – View File Start</h2><p>Shows the first few lines of a file.</p><pre><code class="language-bash">head -n 20 /etc/passwd
</code></pre><p>🔹 Useful for checking headers of config/data files.</p><h2>8. <code>grep</code> – Search Text</h2><p>Search patterns inside files or streams.</p><pre><code class="language-bash">grep "ERROR" /var/log/syslog
</code></pre><p>🔹 Used daily for debugging logs or scanning configs.</p><h2>9. <code>find</code> – Search Files</h2><p>Locate files by name, type, or time.</p><pre><code class="language-bash">find /var/www -name "*.log"
</code></pre><p>🔹 Saves time when tracking down config or log files.</p><h2>10. <code>chmod</code> &amp; <code>chown</code> – Permissions</h2><p>Change file permissions and ownership.</p><pre><code class="language-bash">chmod 644 config.yaml
chown ubuntu:ubuntu config.yaml
</code></pre><p>🔹 Critical for fixing permission issues in deployments.</p><h2>11. <code>df</code> – Disk Usage</h2><p>Check available disk space.</p><pre><code class="language-bash">df -h
</code></pre><p>🔹 Helps prevent outages caused by full disks.</p><h2>12. <code>du</code> – Directory Size</h2><p>Measure size of files/directories.</p><pre><code class="language-bash">du -sh /var/log/*
</code></pre><p>🔹 Great for tracking large log files eating up storage.</p><h2>13. <code>ps</code> – Process Status</h2><p>Check running processes.</p><pre><code class="language-bash">ps aux | grep nginx
</code></pre><p>🔹 Useful for debugging stuck services or containers.</p><h2>14. <code>top</code> / <code>htop</code> – Resource Usage</h2><p>Monitor CPU, memory, and process usage.</p><pre><code class="language-bash">top
</code></pre><p>🔹 Vital for identifying high-resource processes during incidents.</p><h2>15. <code>kill</code> – Terminate Processes</h2><p>Stop processes by PID.</p><pre><code class="language-bash">kill -9 12345
</code></pre><p>🔹 Important for quickly killing hung or runaway processes.</p><h2>16. <code>systemctl</code> – Service Control</h2><p>Manage systemd services.</p><pre><code class="language-bash">systemctl status nginx
systemctl restart docker
</code></pre><p>🔹 Core to managing production services.</p><h2>17. <code>journalctl</code> – View Service Logs</h2><p>Inspect logs from systemd-managed services.</p><pre><code class="language-bash">journalctl -u nginx --since "10 min ago"
</code></pre><p>🔹 Easier than digging into log files manually.</p><h2>18. <code>scp</code> – Secure Copy</h2><p>Copy files between local and remote servers.</p><pre><code class="language-bash">scp file.txt user@server:/home/user/
</code></pre><p>🔹 Everyday DevOps need for moving configs, scripts, or backups.</p><h2>19. <code>ssh</code> – Remote Access</h2><p>Log in to remote servers.</p><pre><code class="language-bash">ssh ubuntu@server-ip
</code></pre><p>🔹 The lifeline for DevOps engineers working on cloud instances.</p><h2>20. <code>tar</code> &amp; <code>gzip</code> – File Archiving</h2><p>Compress and extract files.</p><pre><code class="language-bash">tar -czvf backup.tar.gz /etc/nginx/
tar -xzvf backup.tar.gz
</code></pre><p>🔹 Essential for backups, deployments, and moving code artifacts.</p><h1>Bonus Commands</h1><ul><li><p><code>wget</code> / <code>curl</code> → Download files or test APIs.</p></li><li><p><code>alias</code> → Shortcuts for repetitive commands.</p></li><li><p><code>history</code> → Check previous commands (super useful for CI/CD debugging).</p></li></ul><h2>Final Thoughts</h2><p>Mastering Linux commands is non-negotiable for DevOps engineers. These 20 commands are the <strong>Swiss Army knife of daily operations</strong> — whether you’re managing cloud servers, troubleshooting Kubernetes nodes, or debugging pipelines.</p><p>👉 Pro tip: build your own <code>.bashrc</code> or <code>.zshrc</code> with <strong>aliases</strong> for these commands to save time and reduce typos.</p><p></p>

Linux & Bash

Top 20 Linux Commands Every DevOps Engineer Should Know