100+ Linux Commands Cheat Sheet (With Practical Examples)

Shell variables are local to the process that creates them. Export a variable when child shells or commands started from this session must inherit it. The table lists the usual commands to display, set, export, or unset environment variables.

The commands under this section are very basic commands and must be known to every system administrator. This is definitely not the complete list of Linux commands for file management but can give you a kickstart and can cover most of the basic to complex scenarios.

For ordering lines in files or pipeline output, see the sort command.

Most of the time we will end up using find command to find files and directories. But I also like which command as it gives is the path of the binary which is required at multiple events when we are required to execute a binary with complete PATH.

These are some of the commands which we use to check the last logged in user information and some other commands to get more details on existing user.

As a sytem and Linux administrator you must be familiar with these commands. These will help you determine the type of server you are working on, such as load, cpu model, hardware model, hardware type etc. Some of the commands may be distribution specific such as hwinfo is only available in SuSE Linux while others are expected to be found on almost all distros.

These Linux commands will help you manage the Linux processes, and will help you troubleshoot any server resource related issues. You can use these commands to monitor your server's resource such as Memory, CPU, disk IO etc.

Process snapshots start with ps aux or ps -ef; see the ps command for column selection and sorting. To send SIGTERM or SIGKILL by PID or process name, see kill and pkill.

These are some of the basic Linux commands to perform user management such as create, modify, delete user or groups.

Linux permission is a very vast topic and here I have only covered the basic commands which we use to assign/modify/remove permissions to files and directories.

This section will help Network engineers who are new to Linux environment. I have tried to place the most used commands for network troubleshooting, we also have tcpdump, iperf, netperf and many other networking tools which are used for troubleshooting network related issues but they can get complicated hence those are not mentioned in this list.

ICMP reachability checks use ping; see the ping command for -c, deadlines, and reading packet loss.

One of the primary roles of system administrator would be to configure partitions, storage layouts in the Linux server. Here you can get the list of most used Linux commands for managing partitions and file systems.

With package manager such as yum, dnf, apt-get, the life of a system administrator becomes very easy. You can easily install, update, remove packages, upgrade server operating system and much more using these commands.

Low-level .rpm work uses rpm -ivh and rpm -qa; see the rpm command before reaching for dnf or yum.

Now you know about most of the Linux commands to manager different areas of Linux server but you must be familiar of how logging works in Linux? This may vary based on different distribution, with old distros we used syslog-ng for logging but now almost all major distros have moved to rsyslog solution.