# Your Go-To Linux Commands Cheat Sheet > Speed up your workflow with this Linux commands cheat sheet—practical, easy to follow, and packed with real-world use cases. Source: https://last9.io/blog/linux-commands-cheat-sheet/ If you work with Linux, the terminal is either your best friend or your worst enemy—sometimes both on the same day. If you're just starting out or managing servers, a solid Linux commands cheat sheet can save you time and frustration. ## Essential Linux Directory Navigation Commands ### 1\. Navigating and Managing Directories Effectively - `pwd` – Prints the absolute path of the current working directory, so you always know where you are. - `ls` – Lists files and directories in the current directory. Use `ls -l` for detailed info and `ls -a` to see hidden files. - `cd ` – Changes the current directory to the specified directory. Example: `cd /home/user/docs`. - `cd ..` – Moves up one level in the directory tree. - `cd -` – Switches back to the previous directory you were in. - `mkdir ` – Creates a new directory. Example: `mkdir new_folder`. - `rmdir ` – Removes an empty directory. For non-empty directories, use `rm -r `. - `rm -r ` – Deletes a directory and all its contents. Use with caution! If you find this Linux cheat sheet helpful, check out our [**Git Commands Cheat Sheet**](https://last9.io/blog/your-go-to-git-commands-cheatsheet/) to level up your version control game. ### 2\. File Creation, Management, and Manipulation - `touch ` – Creates an empty file or updates the timestamp if the file exists. - `cp ` – Copies files or directories. Example: `cp file1.txt /backup/`. - `mv ` – Moves or renames files. Example: `mv oldname.txt newname.txt`. - `rm ` – Deletes a file permanently. - `cat ` – Displays the content of a file. Combine with `| more` to paginate. - `less ` – Opens a file for reading, allowing scrolling up and down. - `head ` – Shows the first 10 lines of a file. Example: `head -20 file.txt` for 20 lines. - `tail ` – Shows the last 10 lines of a file. Use `tail -f file.log` to monitor a log file in real time. ## Managing Users and Permissions in Linux ### 3\. User and Group Management - `whoami` – Displays the currently logged-in user. - `who` – Lists all users currently logged in. - `id` – Shows the user ID (UID) and group ID (GID). - `adduser ` – Creates a new user and sets up a home directory. - `passwd ` – Changes the password for a user. - `usermod -aG ` – Adds a user to an existing group. - `deluser ` – Deletes a user account. ### 4\. Managing File Permissions and Ownership - `ls -l` – Lists files with detailed permission settings. - `chmod ` – Changes file permissions. Example: `chmod 755 script.sh` (rwx for owner, rx for others). - `chown : ` – Changes file owner and group. - `chgrp ` – Changes the group ownership of a file. - `umask ` – Sets default file permissions for newly created files. If you're working with Kubernetes, our [**kubectl Commands Cheat Sheet**](https://last9.io/blog/kubectl-commands-cheatsheet/) will make your life easier. ## Monitoring and Managing System Processes ### 5\. Process Management and Monitoring Tools - `ps aux` – Lists all running processes with details. - `top` – Shows real-time system processes and resource usage. - `htop` – Interactive version of `top`, requires installation. - `kill ` – Terminates a process by ID. Example: `kill 1234`. - `pkill ` – Kills a process by its name. Example: `pkill firefox`. - `jobs` – Lists background processes. - `fg %` – Brings a background job to the foreground. - `nohup &` – Runs a command immune to logout. ## Networking and Connectivity in Linux ### 6\. Essential Networking Commands for Troubleshooting - `ip a` – Displays IP addresses of network interfaces. - `ping ` – Tests connectivity to a host. - `curl ` – Fetches a webpage or API response. - `wget ` – Downloads a file from the internet. - `netstat -tulnp` – Shows active network connections. - `ss -tulnp` – Modern alternative to netstat. - `nslookup ` – Queries DNS records. - `dig ` – Retrieves detailed DNS info. - `traceroute ` – Shows the route packets take. If you often run commands inside Kubernetes pods, check out our [**kubectl exec guide**](https://last9.io/blog/kubectl-exec-commands-examples-and-best-practices/) for examples and best practices. ## Disk Usage, Storage, and File System Management ### 7\. Analyzing and Managing Disk Usage - `df -h` – Displays available disk space. - `du -sh ` – Shows the size of a directory. - `mount` – Lists mounted filesystems. - `umount ` – Unmounts a filesystem. - `fsck ` – Checks and repairs filesystems. ## Managing Software and Packages ### 8\. Handling Software Packages Efficiently #### Debian-based (Ubuntu, Debian) - `apt update` – Refreshes package lists. - `apt upgrade` – Upgrades installed packages. - `apt install ` – Installs a package. - `apt remove ` – Uninstalls a package. - `dpkg -i ` – Installs a `.deb` package. #### RHEL-based (CentOS, Fedora) - `yum update` – Updates all packages (CentOS 7). - `dnf update` – Updates all packages (Fedora, CentOS 8+). - `yum install ` – Installs a package. - `dnf install ` – Installs a package (Fedora, CentOS 8+). - `rpm -i ` – Installs an `.rpm` package. ## System Performance and Monitoring ### 9\. Checking System Health and Performance - `uptime` – Shows system uptime. - `free -h` – Displays memory usage. - `vmstat` – Reports system performance. - `iostat` – Displays CPU and disk usage stats. - `sar` – Collects system activity data. - `mpstat` – Displays per-core CPU usage. - `iotop` – Monitors disk I/O in real-time. If you've ever wondered why Linux kills processes under memory pressure, our [**OOM Killer guide**](https://last9.io/blog/understanding-the-linux-oom-killer/) breaks it down. ## Handling Logs and Troubleshooting ### 10\. Managing and Analyzing Logs - `dmesg` – Views system boot logs. - `journalctl` – Views system logs. - `tail -f /var/log/syslog` – Monitors system logs live. - `tail -f /var/log/auth.log` – Monitors authentication logs. ## Automating Tasks and Scheduling ### 11\. Setting Up Cron Jobs and Scheduled Tasks - `crontab -l` – Lists scheduled cron jobs. - `crontab -e` – Edits cron jobs. - `crontab -r` – Removes all cron jobs. - `systemctl list-timers` – Displays systemd timers. - `at