📁📂 File and Directory Management
- 🗂️ ls – List directory contents
- 🕵️♂️ ls -la – List all files with permissions
- 📂 cd /path – Change directory
- 📌 pwd – Print working directory
- 📁 mkdir dir – Create a new directory
- 🗑️ rmdir dir – Remove empty directory
- ❌ rm file – Remove file
- 💣 rm -r dir – Remove directory and its contents
- 📄➡️📄 cp src dest – Copy file or directory
- 🔀 mv old new – Move or rename file/directory
- 🔎 find / -name file – Find file by name
📄📝 File Viewing and Editing
- 👀 cat file – View file content
- 📜 less file – Scroll through file
- 🔝 head file – Show first 10 lines
- 🔚 tail file – Show last 10 lines
- 📡 tail -f file – Monitor file in real-time
- 🧑💻 nano file – Edit file in Nano editor
- 🧙♂️ vim file – Edit file in Vim editor
- 🆕 touch file – Create an empty file
- 📘 file name – Show file type
🔍📊 Search and Filter
- 🧐 grep ‘text’ file – Search for text in file
- 🔁 grep -r ‘text’ dir – Recursive grep in directory
- 📏 awk ‘{print $1}’ – Print the first column
- ✂️ cut -d’:’ -f1 file – Cut by delimiter
- 📊 sort file – Sort file contents
- 🧹 uniq file – Remove duplicate lines
🔐🔧 Permissions and Ownership
- 🔐 chmod 755 file – Set file permissions
- 👤 chown user file – Change file owner
- 👥 chgrp group file – Change group ownership
- 📋 umask – Show default permission mask
💻📈 System Info & Monitoring
- 📊 top – Display running processes
- 🎛️ htop – Interactive process viewer (if installed)
- 🧾 ps aux – List all processes
- 💽 df -h – Show disk usage in human-readable format
- 📦 du -sh dir – Show size of a directory
- 🧠 free -h – Show memory usage
- ⏱️ uptime – Show system uptime
- 🔧 uname -a – Show kernel and system info
- 🏷️ hostname – Display system hostname
- 🙋 whoami – Show current logged-in user
🌐📡 Networking
- 📡 ip a – Show IP addresses
- 📟 ifconfig – (Older) show IP config
- 📶 ping host – Ping a remote host
- 🛠️ netstat -tuln – Show open ports (if installed)
- 📈 ss -tuln – List sockets (faster replacement for netstat)
- 🌐 curl url – Make HTTP request
- 📥 wget url – Download from web
- 🚚 scp file user@host:/path – Copy file over SSH
- 🔐 ssh user@host – SSH into a remote host
📦📤 Package Management
Debian/Ubuntu (APT-based)
- 🔄 apt update – Refresh package lists
- ⬆️ apt upgrade – Upgrade all packages
- 📥 apt install pkg – Install a package
- 🗑️ apt remove pkg – Remove a package
RHEL/CentOS (YUM/DNF-based)
- 📥 yum install pkg – Install a package
- 🗑️ yum remove pkg – Remove a package
- 📥 dnf install pkg – (Fedora/CentOS 8+) install package
🔁🧩 Miscellaneous
- 🕰️ history – Show command history
- 🧩 alias ll=‘ls -la’ – Create alias
- 🔄 reboot – Reboot system
- ⛔ shutdown -h now – Shutdown immediately
- 📖 man command – View manual for a command