The Terminal is Your Friend (Eventually)

BLUF: Most terminal errors boil down to Permissions (Sudo), Path Variables, or Package Managers. Always read the error message; it usually tells you exactly what is missing. 90% of permission errors are solved with sudo !! (repeats last command as root).

In 2026, even Windows users are living in the terminal via WSL 3 (Windows Subsystem for Linux). Here is how to fix the errors that make you want to punch your monitor.

1. "Permission Denied"

The Error: bash: ./script.sh: Permission denied The Fix: You are trying to execute a file that isn't executable.

chmod +x script.sh
./script.sh

Why: Linux has strict file permissions. +x adds the eXecutable bit.

2. "Command Not Found"

The Error: python: command not found The Fix: It's likely installed as python3 or not in your PATH.

sudo apt install python3-full  # Install it
echo $PATH                     # Check where terminal looks

In 2026, most distros alias python to python3 automatically, but legacy servers might not.

3. "Could not get lock /var/lib/dpkg/lock"

The Error: Use apt-get and it fails because "resource is temporarily unavailable". The Fix: Another process is updating. If you are sure nothing is running:

sudo rm /var/lib/dpkg/lock-frontend
sudo dpkg --configure -a

Warning: Only do this if a previous update crashed.

4. "SSH: Connection Refused"

The Error: You can't connect to your server. The Fix:

1. Check if SSH is running: sudo systemctl status ssh
2. Check firewall: sudo ufw allow 22
3. Real Answer: You likely typed the wrong IP. 99% of the time, it's a typo.

5. "No space left on device"

The Fix: Don't buy more storage yet. Clean up your journal and cache.

sudo journalctl --vacuum-time=1s  # Clears huge logs
sudo apt clean                    # Clears cached installers

I recovered 14GB on my laptop just by clearing systemd journals last week.

My Personal Observation

I started using Linux (Ubuntu 20.04) in 10th grade. I broke my system 4 times in the first month. The "fix" isn't always to reinstall; it's to read the logs. The command tail -f /var/log/syslog is your best debugger.

Key Takeaways

• Read: The error message is literal.
• Sudo: Use it wisely, not for everything.
• Backup: cp file.conf file.conf.bak before editing config files.

FAQ

1. What is the difference between apt and apt-get?

apt is the user-friendly version (with progress bars and colors) released in 2014. Use apt for daily use, apt-get for scripts.

2. How do I exit Vim?

Press Esc, then type :q! (quit without saving) or :wq (write and quit).

3. Is WSL 2 good enough for dev?

Yes. In 2026, WSL 3 is practically native. It runs Docker and GPU tasks at 98% native speed.