🐧 Daily Linux Commands

Frequently used Linux commands for daily operations

📂 File and Directory Commands

pwd - Print current working directory
ls -l - List files with permissions and sizes, detailed info
cd /path/to/dir - Change directory
mkdir dirname - Create a new directory
rmdir dirname - Remove empty directory
rm -rf dirname - Remove directory and contents (⚠️ caution!)
cp file1 file2 - Copy files
mv file1 file2 - Move or rename files
touch filename - Create empty file

📑 Viewing and Editing Files

cat filename - Show file content
head -n 10 filename - Show first 10 lines
tail -n 10 filename - Show last 10 lines
less filename - View file one page at a time
nano filename - Simple terminal text editor
vi filename or vim filename - Advanced text editor

🔍 Searching & Filtering

grep "text" filename - Search for text in file
grep -r "text" /path - Recursive search in directories
find /path -name "file.txt" - Find files by name
find /path -type f -size +10M - Find large files
sort filename - Sort file content
uniq filename - Remove duplicate lines

📊 Disk and System Info

df -h - Disk space usage
du -sh * - Size of each file/folder
free -h - Memory usage
uptime - System load and uptime
uname -a - Kernel and system info
top or htop - Running processes
who / w - Logged-in users

🛠️ Permissions & Ownership

chmod +x script.sh - Make a script executable
chown user:group file - Change file owner
chmod 755 file - Set permissions (rwxr-xr-x)
umask - View default permissions mask

🌐 Network Commands

ping google.com - Test connectivity
curl -I http://example.com - Fetch HTTP headers
wget http://example.com/file - Download file
ss -tuln or netstat -tuln - Show listening ports
ip a - Show network interfaces

📦 Package Management

Debian / Ubuntu (APT)

sudo apt update - Refresh package database
sudo apt upgrade - Install available updates
sudo apt install pkg - Install a package
sudo apt remove pkg - Remove package
dpkg -l - List all installed packages
sudo dpkg -i file.deb - Install a downloaded .deb package

RHEL / CentOS / Fedora (YUM / DNF)

sudo yum update - Update packages
sudo yum install pkg or sudo dnf install pkg - Install
sudo yum remove pkg - Remove package
sudo rpm -ivh file.rpm - Install a local .rpm file
rpm -qa - List installed packages
rpm -ql packagename - Show installed files of a package

⚙️ Process Management

ps aux - List all running processes
kill PID - Kill process by PID
kill -9 PID - Force kill a process by PID
jobs / bg / fg - Manage background jobs
htop - Interactive process viewer (if installed)

⏲️ Scheduling Jobs

crontab -e - Edit scheduled tasks
crontab -l - List user cron jobs
at 10:00 - Run command at specific time

💡 Tips

Use man command to get help on any command.
Use --help with most commands for quick reference.
Always double-check before using rm -rf or sudo.