How to use SSH and 20 Basic Linux Commands?

man

Man is a built-in manual command that helps users understand the command’s usage with the possible arguments and syntax information. Example: man tar, man mv, etc. To change the page press space bar and to exit from the manual press q.

history

History command helps you to find previously executed commands on the Linux terminal. You can also wipe out the previous history using the clear command.

top

The top command helps you track down all the processes running on the Linux system. This is the most helpful command used while troubleshooting the problems. There are several variations of the top command such as top c, top i, etc.

mv

Mv command works for the two operations, a) To move the files; b) To rename directory/file. If you define the unique destination in the mv command, it will work for moving the files, and if you didn’t mention the unique destination, then the command will help you rename the directory/file.

wget

To download the non-interactive files from the web you can take the help of the wget command. The syntax of the wget command is pretty straightforward wget <URL>. Also, get work with both HTTP and HTTPS.

ping

There are two major reasons to use the ping command. First, Linux/Windows use the ping command to check the latency of the destination server. Second, Linux/Windows uses the ping command to check the availability of the destination server.

kill

If one of the Linux server’s programs is stuck with the process, or you would like to kill all processes running under a Linux user, then you can take the help of the kill command. There are 64 signals which work with the Kill command. The syntax of the kill command is Kill <Signal ID> <PID/User>. The most command signal ID we use to terminate the process is -9 forcefully.

ps

Ps command mostly gets in use while monitoring the Linux server. The primary task of the ps command is to monitor the selection of the active processes running on the Linux server. Administrators commonly use ps ax or ps axu command to check every process running on the linux system.

cd

Cd command gets used while navigating through the files and directories on the Linux server. This is one of the most common commands the Linux users use daily. Suppose you would like to navigate from /home/host/KnownHost directory to /home/best/LinuxHost then you would use the command cd /home/best/LinuxHost.

pwd

On Linux, you don’t want to work on the unwanted directory; to avoid such consequences, you must check the current working directory; to check the present working directory on Linux, use the pwd command.

ls

To view the current working directory’s content, Linux has a command ls. Variation of the command helps you list the present files with their owner, group, permission, size, and date of modification details.

mkdir

To create the directory on the Linux system, use the mkdir command. For example, if you want to create the KnownHost directory, simply run the mkdir KnownHost command. To create multiple directory you can use the syntax: mkdir <directory 1> <directory 2> <directory 3>.

rmdir

Using mkdir, we learned how you could create the directories. To remove the directory use the command rmdir. For example, if you want to remote the KnownHost directory from the current working destination, simply run the rmdir KnownHost command. Note that, you can delete only empty directories using the rmdir command.

rm

You use the rm command to delete every file and directory on the Linux system. Variation of the rm’s commands helps you remove the recursive directories and the files simultaneously. To remove single file or directory use rm <directory/file path>, to recursively delete the directories run the rm -r <directory/file path>, to forcefully and recursively remove the directories/files run the rm -rf <directory/file path> command.

touch

You can use the touch command to create a plain new file on the Linux system. For example, to create a KnownHost.txt file at /home/admin directory, you could run touch /home/admin/KnownHost.txt.

grep

Grep is another most commonly used command by Linux users to search/find through the text file. For example, if you have a KnownHost.txt file on the Linux system and want to search for a word best, then you could use grep best KnownHost.txt, and the result will show up the lines which have the best word in it.

chmod

Another most commonly used command in Linux for changing read, write and execute permission for World, Group, and User. For example, if you would like to change the permission of the KnownHost directory to rwxr-xr-x i.e., 755 then you could use the chmod 755 KnownHost.

chown

You can use it to change the ownership of the file/directory in the Linux chown command. For example, if you want to change the ownership of the KnownHost directory to john user, you could use the command, chown john KnownHost. Another example, suppose if you would like to change the owner of the KnownHost directory to lora and group to USA, then use chown lora:USA KnownHost command.

jobs

This basic command will display all the jobs and their status opened by the shell on the Linux system. To monitor and check the job status, you could use this command.

nano

Nano is a popular and more accessible text editor used on Linux systems. Due to its simple text editor feature and the GUI-like interface enabled beginners to edit the text files the easier—furthermore, many popular command-line text editors such as vi, vim, etc.