Setting Up Home Internet in Thailand: What to Do First

Fixing “sudo: command not found” on Linux

Seeing sudo: command not found doesn’t necessarily mean you need to install anything. You might already be root, your shell might not be able to find the sudo program, or you may be working in a…

• "sudo: command not found" errors may not always require sudo installation.
• Check user identity with whoami or id -u; examine /usr/bin/sudo and PATH.
• Install sudo as root using distribution-specific package manager, then add user to sudo group.

2h ago ·dev.to

Find the Right IP Address on Linux (Without Guessing)

If hostname -I prints three addresses and you’re not sure which one to use, the problem isn’t finding an IP—it’s identifying what each address is for.

• Use hostname -I for quick IP overview
• Employ ip -br addr show for interface-specific details
• Check public IP with curl ifconfig.me

2h ago ·dev.to

TCP Port 8009: Identify the Listener Before You Secure It

An open TCP port 8009 is a clue, not an answer. It is commonly used by Apache Tomcat’s AJP connector, but the port number alone cannot tell you what service is running—or whether it is exposed in a…

2h ago ·dev.to

Copying Directories in Linux: Choose Between cp -r, cp -a, and rsync

Copying a directory in Linux is easy; copying it to the right shape is where mistakes happen. The destination may end up with an unexpected nested folder, hidden files may be skipped by a wildcard, or…

• Use cp -r for basic directory copy, preserving directory tree structure
• Include dot for hidden files in source path when copying with cp -r
• Use cp -a for metadata preservation, symbolic link handling in cp

2h ago ·dev.to

What Nginx Does in a Web App: Static Server, Reverse Proxy, and More

When a browser requests your app, which process actually handles the request? In many deployments, it’s Nginx at the public edge—and an application process behind it doing the app-specific work.

• Nginx serves as a static server, delivering HTML, JavaScript, CSS, and images directly from disk.
• Handles TLS encryption, routing, and static file delivery, complementing application server's role.

2h ago ·dev.to