Search by keyword or category to quickly find command usage and examples.
ls -lah /var/log
List files in human-readable format with details.
find /var/log -type f -name "*.log"
Recursively find files by name pattern.
grep -rin "error" /var/log
Search keyword in file contents with line numbers.
tar -czf logs.tar.gz /var/log/nginx
Archive and compress a directory into tar.gz.
unzip archive.zip -d output/
Extract a zip file to a target folder.
chmod +x run.sh
Change file mode, add execute permission.
sudo chown -R www-data:www-data /var/www/app
Recursively change file owner and group.
sudo systemctl status nginx
Check status of a systemd service.
sudo journalctl -u nginx -n 50
View recent logs for a specific service.
ps aux | grep nginx
List processes and filter by keyword.
kill -9 $(pgrep nginx)
Force kill processes matching the keyword.
df -h
Show disk usage by filesystem (human-readable).
du -sh *
Summarize size of items in the current directory.
ping -c 4 example.com
Test network connectivity and latency.
curl -I https://example.com
Fetch only HTTP response headers to check availability.
scp ./file.txt user@server:/home/user/
Securely copy files to a remote host over SSH.
ssh user@server
Log in to a remote host via SSH.
sudo useradd -m deploy && sudo passwd deploy
Create a new user and set password; -m creates the home directory.
A quick Linux command dictionary with keyword/category search, short descriptions, and ready-to-copy examples.