Mastering Linux: Essential Commands for Operating System Management
The Basics of the Linux Operating System
Linux is an operating system that runs on computers and laptops. It offers a text interface called the terminal or command line.
Using these commands lets you manage the computer and troubleshoot software issues. Some examples are ls – displays folder and file contents; du – reports disk usage; top – shows running processes; ps – prints information about a process; and chmod – changes access permissions for files and directories.
When you work with Linux on a regular basis it’s helpful to have some basic commands memorized. These can be very useful whether you’re a fresh newbie or an old salty system administrator from the dark days of DOS and UNIX.
Some of the basics commands include pwd (print working directory) which shows you the path to your current working directories. ls (list directory contents) lists the content of a folder and usually displays it in color coded format where plain text is data files or text documents, blue entries are directories, and green entries are executable programs.
cat (concatenate) is a handy command that can be used to display file contents or adjoin content from multiple files into one output file. tar (compress) is useful for creating archive files, or “tarballs”, that contain several files packaged together for portability and storage. Finally, the man command provides quick help for any command. It is similar to the HELP command found in most software.
The lsof command shows all the files that are currently open on the system. It can be used to check which processes are using a particular file. It also offers other options like -c, which separates lines based on delimiters, and -u, which makes it case insensitive.
Other advanced Linux commands include the ifconfig command, which displays information about network interfaces on a system. It is often used by system administrators to troubleshoot issues and set up network interfaces for optimal performance. It can also help with the configuration of DHCP servers.
The uname and whoami commands display detailed information about the Linux operating system. They can be used to identify the machine name, kernel, and other information. These commands are useful for Oracle users, particularly DBAs and developers. They can also be used to check the ORACLE_SID. The cd and mv commands are helpful for moving between directories. They can also be used to create a new directory.
Linux is a popular choice for developers and system administrators because of its superior security, open-source software, and command line capabilities. Knowing a few basic commands like uname, wget, and htop can help you make the most of your VPS and manage your system efficiently.
Linux has a number of package management tools that allow users to install, upgrade, and remove applications without manual intervention. These programs, called packages, are stored in central repositories that are designed for a specific Linux distribution and version. They can also be distributed as source code that can be manually compiled and installed by the user.
A package manager can often detect that a piece of software requires other software, libraries, or configuration files to run. These additional requirements are known as dependencies. Typically, a dependency resolution process is used to ensure that when a package is upgraded, all of its dependencies are updated as well.
Whether Linux is used on desktops, servers, or smartphones, the system offers many tools for network management. These commands are executed via a text interface known as a terminal, command line, or console. They are a vital tool for sysadmins, who use them to set up, troubleshoot, and manage Linux systems’ network connections.
Among the most useful networking tools in Linux are ifconfig, ip, ethtool, netstat, traceroute, and nslookup. ifconfig shows the system’s network interface configurations, including IP addresses, netmasks, and up and down controls. It also lets sysadmins change an interface’s IP address or disable it entirely.
Other useful network management commands include uname, which displays the system’s current user and id, and whoami, which provides information about a Linux account’s ownership. The exit command allows you to leave the shell, and ctrl+C clears the terminal screen.