Linux commands that every DevOps engineer should know

Here are some essential Linux commands that every DevOps engineer should know. These commands cover a range of functionalities including file and directory management, process management, system monitoring, networking, and package management

File and Directory Management

• ls: List directory contents.
• cd: Change the current directory.
• pwd: Print the current working directory.
• mkdir: Create a new directory.
• rm: Remove files or directories.
• cp: Copy files or directories.
• mv: Move or rename files or directories.
• touch: Create an empty file or update the timestamp of a file.
• find: Search for files and directories.
• grep: Search for patterns within files.

File Viewing and Editing

• cat: Concatenate and display file content.
• less: View file content one page at a time.
• head: Display the first few lines of a file.
• tail: Display the last few lines of a file.
• nano / vi / vim: Text editors for file editing.

Process Management

• ps: Display currently running processes.
• top: Display real-time system statistics and running processes.
• htop: An improved, interactive process viewer (needs to be installed separately).
• kill: Terminate processes by PID.
• killall: Terminate processes by name.
• systemctl: Manage systemd services.

System Monitoring

• df: Display disk space usage.
• du: Display disk usage of files and directories.
• free: Display memory usage.
• uptime: Display how long the system has been running.
• iostat: Display CPU and I/O statistics (requires sysstat package).
• vmstat: Display virtual memory statistics.

Networking

• ifconfig: Display or configure network interfaces (deprecated in favor of ip command).
• ip: Display or configure IP addresses, routes, and devices.
• ping: Check connectivity to a host.
• netstat: Network statistics (deprecated in favor of ss).
• ss: Display socket statistics.
• traceroute: Display the route packets take to a network host.
• curl: Transfer data from or to a server.
• wget: Download files from the web.

Package Management

Debian-based distributions (e.g., Ubuntu):

• apt-get / apt: Package management commands.
  • sudo apt-get update
  • sudo apt-get install package_name
  • sudo apt-get upgrade
  • sudo apt-get remove package_name
  • sudo apt-cache search package_name

Red Hat-based distributions (e.g., CentOS, Fedora):

• yum / dnf: Package management commands.
  • sudo yum install package_name
  • sudo yum update
  • sudo yum remove package_name
  • sudo yum search package_name
  • sudo dnf install package_name
  • sudo dnf update
  • sudo dnf remove package_name
  • sudo dnf search package_name

User and Permission Management

• chmod: Change file permissions.
• chown: Change file owner and group.
• usermod: Modify user accounts.
• passwd: Change user password.

Miscellaneous

• alias: Create command shortcuts.
• crontab: Schedule periodic tasks.
• tar: Archive files.
• ssh: Securely connect to remote servers.
• scp: Securely copy files between hosts.