This issue can be solved by following simple commands. All you need is editor and sudo permission(usually your same password as user).
Open the file /etc/gdm3/custom.conf is this does not exist in your machine open /etc/gdm3/daemon.conf.
Then uncomment the line WaylandEnable=false that is remove the # at the start of the line, save it and then do a reboot.
This is one of the most common problems that one might encounter these days. This can be due to hardware of software.
If the issue is because of software we can fix it using below mentioned ways..
First print out the output of the command dmesg and see if there are any errors printed in red color which does symbolize that you have a file system error.
Note: sda5 means the disk that you want to check for errors. You can see the name of your disk by using the command df -h
Install smartctl a tool to check your hard disk for errors.
After installing smartctl run the following command.
smartctl -t long /dev/sda5
Then carefully see the output of above command it displays the time it will take to complete the test you have just started. To view the test run the below command.
smartctl -l selftest /dev/sda5
Now run below commands to check the health of your hard disk.
smartctl -a /dev/sda5
smartctl -H /dev/sda5
You can also add a line to your grub file located at /etc/default/grub or modify the line if it already exists.
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash libata.force=noncq"This will make sure that while rebooting you run a force check for errors in your file system. Be careful because you might need to back up your data as you may lose some of it.
Another way to go into recovery mode is to press ESC while rebooting and choose recovery mode. This will make sure to fix file system errors also you can choose to run fsck/resume normal boot in the options provided.
The command CD stands for change directory. CD can be used in many ways to navigate between multiple directories just like we traverse in GUI.
cd <filename>
The above command will move to the directory specified in the angular brackets. But you have to make sure that the name given here is present in the current directory. You can see what are the folders/files in the current directory using the command LS. Also you can check your current working directory using the command PWD.
cd /path/to/another/folder
The above command will take to another folder that is far away from the current working directory. Make sure that the specified path exists. You can check the path of the current structure using the command TREE.
cd ..The above command will move the current working directory to one level back.
cd
The above command without any arguments will take you to the home directory no matter where your current working directory is.
There is a video example for the same, watch it below
How to use vim in Linux.
Vim has two modes. Command mode and insert mode. In command mode we can tell the editor to substitue, edit, insert, append, save, quit etc. By default vim opens in command mode. To switch to insert mode press “i” in command mode without quotes. Here you can edit the file with whatever content you want to.
To switch to command mode press “Esc” key. Here we can give commands to save and quit. To save press :w then the file will be saved and to save and quit press :wq.
Here is a video enplaning the same.
There are terminal utilities like ‘diff’ and ‘vimdiff’ in Linux to visualise the differences in two files. But sometimes this visual presentation can be difficult to be viewed and understanding it might take some time as it can be confusing to analyse.
Using meld we can visually the differences in a less confusing way and understand it more easily. Here is a screenshot of the same.
Bonus advantage is that we can view the graphical difference of two folders also.
To install Meld you can install from command line using the following command
sudo apt install meld