Are you interested in mastering the Linux command line for DevOps purposes? Learn the essential Basic Linux Commands for DevOps in this comprehensive beginner’s guide.
Master the fundamental commands to enhance your DevOps skills
This comprehensive beginner’s guide will walk you through 20 basic Linux commands that every DevOps enthusiast should know.
Whether you’re a beginner or have some experience with Linux, this guide will help you enhance your skills and improve your efficiency.
So, let’s dive into the world of Linux command line!
- 1 Introduction
- 1.1 1.To Know the OS Type
- 1.2 2.To Know the CPU Architecture
- 1.3 3.To Check the Kernel Version
- 1.4 4.To Get the OS Name, Release, Version
- 1.5 5.To List the System Hardware
- 1.6 6.To Get the CPU Details
- 1.7 7.To Check System Memory
- 1.8 8.To Check Virtual Memory Stats
- 1.9 9.Free Memory Cache, Dentries, and Inodes (with Root Access)
- 1.10 10.To Print Process-Specific Memory Utilizations
- 1.11 11.To Search Packages for Installation
- 1.12 12.To Install a Package
- 1.13 13.To Uninstall a Package
- 1.14 14.To List the Mounted Disk Drives
- 1.15 15.To Mount a Volume
- 1.16 16.To List the Biggest Files from a Directory
- 1.17 17. To Find a File in a Directory
- 1.18 18. To Search for a Text String in a Directory
- 1.19 19. To Find Text String from a Given Directory
- 1.20 20. To Remove a Directory
Linux commands play a vital role in the DevOps ecosystem.
They allow developers and system administrators to interact with the operating system efficiently and perform a variety of tasks.
Whether you’re managing servers, deploying applications, or automating processes, having a solid understanding of basic Linux commands is essential.
In this guide, we will cover 20 fundamental Linux commands for DevOps beginners.
1.To Know the OS Type
To determine the type of operating system you are using, use the following command in your terminal:
$ uname -o
This command displays the type of your operating system. For example, if you’re using a Linux-based operating system, it will show “GNU/Linux.“
2.To Know the CPU Architecture
If you want to find out the CPU architecture of your system, use the following command:
$ uname -m
Executing this command will reveal the CPU architecture, such as “x86_64” for 64-bit systems or “armv7l” for ARM-based systems.
3.To Check the Kernel Version
To check the version of the Linux kernel running on your system, enter the following command:
$ uname -r
Running this command will provide you with the kernel version number, which is crucial for understanding the features and compatibility of your Linux system.
4.To Get the OS Name, Release, Version
To retrieve detailed information about the OS name, release, and version, execute the following command:
$ cat /etc/os-release
This command retrieves the contents of the “/etc/os-release” file, which contains details about your operating system,
such as the name (e.g., “Ubuntu”), release version (e.g., “20.04”), and other pertinent information.
NAME="Ubuntu" VERSION="18.04.1 LTS (Bionic Beaver)" ID=ubuntu ID_LIKE=debian PRETTY_NAME="Ubuntu 18.04.1 LTS" VERSION_ID="18.04"
5.To List the System Hardware
If you want to obtain a comprehensive list of the hardware components in your system, use the following command:
Running this command provides a detailed summary of your system’s hardware configuration, including information about the CPU, memory, storage devices, network adapters, and more.
*-cpu description: CPU product: Intel(R) Core(TM) i7-8700K CPU @ 3.70GHz vendor: Intel Corp. ...
6.To Get the CPU Details
To retrieve detailed information about your system’s CPU, enter the following command:
Executing this command will display comprehensive information about your CPU, such as the number of cores, CPU speed, cache sizes, architecture, and other relevant details.
Architecture: x86_64 CPU op-mode(s): 32-bit, 64-bit Byte Order: Little Endian ...
7.To Check System Memory
To check the memory usage on your system, you can use the
free command with the
-h - Displays memory in human-readable format (e.g., GB, MB)
-m - Displays memory in megabytes
$ free -hor
$ free -m
Both of these commands provide information about your system’s memory usage, including the total memory, used memory, free memory, and memory used by buffers and cache.
total used free shared buff/cache available Mem: 7.7G 2.9G 3.5G 257M 1.2G 4.0G Swap: 2.0G 0B 2.0G
8.To Check Virtual Memory Stats
To obtain statistics about the virtual memory usage, you can use the
vmstat command with the
-S m option:
$ vmstat -S m
This command provides a snapshot of your system’s virtual memory usage, including information about active, inactive, and free memory, as well as swap usage.
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 3612 282 1289 0 0 4 13 22 13 0 0 100 0 0
9.Free Memory Cache, Dentries, and Inodes (with Root Access)
To free up memory cache, dentries, and inodes, you can use the following command:
$ echo 3 > /proc/sys/vm/drop_caches
Executing this command clears the memory cache, dentries, and inodes, which can help improve system performance and free up memory resources.
Note: This command requires root access.
10.To Print Process-Specific Memory Utilizations
If you want to view the memory usage of processes running on your system, use the following command:
$ ps aux --sort=-%mem
This command lists all running processes along with their memory utilization, sorted in descending order. It provides insights into which processes consume the most memory resources.
USER PID %CPU %MEM VSZ RSS TTY STAT START TIME COMMAND john 1672 0.0 5.3 2213304 87620 tty2 Sl+ Jun23 0:19 chrome ...
Must Read: Top 50 Linux Commands Basic To Advance
11.To Search Packages for Installation
To search for packages available for installation, you can use the
apt search command followed by the package name:
$ apt search <package name>
This command searches the package repository for packages matching the specified keyword. It helps you find relevant packages that can be installed on your Linux system.
$ apt search python-boto
12.To Install a Package
To install a package using
apt-get, run the following command:
$ sudo apt-get install <package name>
Running this command installs the specified package on your system. Make sure to replace <package name> with the actual name of the package you want to install.
$ sudo apt-get install python-boto
13.To Uninstall a Package
If you want to remove a previously installed package, use the following command:
$ sudo apt-get remove <package name>
Executing this command removes the specified package from your system, freeing up disk space and ensuring that any associated configurations are also removed.
$ sudo apt-get remove python-boto
14.To List the Mounted Disk Drives
To view a list of currently mounted disk drives on your system, enter the following command:
$ df -kh
This command displays information about the disk space usage of all mounted file systems, including details such as the total size, used space, available space, and mount point.
Filesystem Size Used Avail Use% Mounted on /dev/sda1 20G 4.5G 15G 24% / tmpfs 3.9G 0 3.9G 0% /dev/shm ...
15.To Mount a Volume
To mount a volume, you need to create a directory first and then use the
$ mkdir -p <directory path> #Create the DIR to mount the volume
$ sudo mount <src path> <above created dir path>
This command creates a directory to serve as the mount point and then mounts the specified volume or device to that directory.
$ mkdir -p /mount-vol $ sudo mount /dev/sdb1 /mount-vol
16.To List the Biggest Files from a Directory
To list the biggest files in a directory, you can use the
head commands together:
$ sudo du -a /dir/ | sort -n -r | head -n 5
Running this command calculates the disk usage of each file in the specified directory, sorts them in descending order, and shows the top 5 files with the largest sizes.
56360116 /dir/large_file1.txt 32490343 /dir/large_file2.txt 21785075 /dir/large_file3.txt ...
17. To Find a File in a Directory
If you need to search for a specific file in a directory, use the
$ find <dir path> -name <filename> -print
This command searches the specified directory and its subdirectories for a file with the specified name and displays its path if found.
$ find /var -name app.log -print
18. To Search for a Text String in a Directory
To search for a specific text string within files in a directory and print the filenames containing that string, use the following command:
$ find /var -type f -print | xargs grep <search text>
Executing this command searches all files in the specified directory and its subdirectories for occurrences of the specified text string and displays the filenames along with the matching lines.
$ find /var -type f -print | xargs grep "error"
19. To Find Text String from a Given Directory
To find a text string within files from a given directory, you can use the
$ grep -rIn <search text> <directory path>
This command recursively searches for the specified text string in all files within the specified directory, displaying the filenames and line numbers of the matching lines.
$ grep -rIn "Hello, World!" /home/user
20. To Remove a Directory
If you want to delete a directory and its contents, use the following command:
$ rm -r <directory path>
This command recursively searches for the specified text string in all files within the specified directory and its subdirectories, displaying the filenames and line numbers of the matching lines.
$ rm -r /home/user/mydirectory
With these 20 basic Linux commands, you are equipped with essential tools for navigating and managing your Linux system. Experiment with them, and you’ll become more comfortable and proficient in the world of Linux and DevOps!
Remember, practice makes perfect, and mastering these commands will enhance your productivity as a developer or system administrator. Enjoy your Linux journey!