15 Essential Linux Commands which the new Linux user Should know
Open a Terminal, give the key combination
Ctrl + Alt + F1
or in Linux Mint Applications + System Tools + Terminal click
1. pwd - Whre I am
pwd is the abrevation of print working directory .You can read more information about it information about it, here. The command pwd print the full filename of the current working directory.
2. cd - Changing Directories with cd
To change directories from the terminal, use the change directory command, cd. Here an example of how to switch to /Pictures directory.
3. ls - List directory contents
To see the contents of a directory (the files and subdirectories), we can use the ls (list) Command. That is very similar to the dir command in Windows.
4. ls -l - Search to the permission of owner, size and when they were modified
5. locate - Searching with locate , this command will go through your entire filesystem and locate every occurrence of that word.
which - Searching with which. The which command is even more specific: it only returns the location of the binaries in the PATH variable in Linux.
6. find - The find command is the most powerful and flexible of the searching utilities. It is capable of beginning your search in any designated directory and looking for a number of different parameters, including, of course, the filename but also the date of creation or modification, the owner, the group, permissions, and size.
Syntax for find:
find directory options expresion
linux@linuxusers:~$ find /¹ -type f² -name firefox³
1- First, I state the directory in which to start the search, in this case /.
2- Then I specify which type of file to search for, in this case f for an ordinary file .
3- Last, I give the name of the file I’m searching for, in this case, Firefox.
7. whatis - The whatis command provides very brief descriptions of a Programm, it to say what does it, more info whatis what does, here.
8. ps aux - The ps aux command Display the processes/programs on the Computer. That provides yours a listing of all the processes running in this system.
9. ps aux | grep Programm/Process - The ps aux | grep Programm/process command display Information about this Programm/Process. When you to wand to see if a Process is running. I can do this by piping the output from ps to grep and searching for a keyword. For example, to find out whether the Firefox service is running, I would enter the following command, linux@linuxusers:~$ ps aux | grep firefox .
10. kill - The kill command is used to terminate a processes manuality.
How to kill a Process:
An example: You Firefox is crash, and you will kill it.
Step 1 - Find out the PID of the Firefox. With linux@linuxusers:~$ ps aux | grep firefox you find the PID number,
Step 2 - Kill the process using the PID number from Firefox, it is 1590 , With Root kill it.
linux@linuxusers:~$ sudo kill 1590
11. whoami - With the command whoami display my username, linux@linuxusers:~$ whoami .
12. passwd - With the command passwd can Password from username change , with Root + passwd + my usarname, linux@linuxusers:~$ sudo passwd linux
1. - Give you current usarname Password
2. - Give you New Password
3. - repeat it
13. lsblk - The lsblk command reads all or the specified Block devices. The lsblk command reads the sysfs filesystem to gather information , more Information lsblk about Options, here
14. df - The df command display how many places have on my Partitions and Hard Disk.
because sometimes indication of size is difficult to see how many places have, with df -lh making it easy to show....
15. shutdown - The shutdown command bring the system down in a secure method .
- shutdown now - put down the system immediately .
- linux@linuxusers:~$ shutdown now
- shutdown -h 30 - put down your computer on 30 minutes .
- linux@linuxusers:~$ shutdown -h 30
- reboot - reboot you Computer immediately .
- linux@linuxusers:~$ reboot