Huy Note:
Cần dùng lệnh khởi tạo nhóm mysql vào hệ thống linux trước khi cài xampp.
addgroup mysql
Lệnh gán quyền cho thư mục.
chown -R root:mysql /opt/lampp/var/mysql/
cấp quyền cho thu mục
chown -R root:mysql /opt/lampp/var/mysql/
chmod 755 /opt/lampp/var/mysql/
thêm tài khoản mysql vào hệ thống
adduser mysql

Step 1: Download the installation package

The first step is to download the XAMPP package for Linux from the official Apache Friends website:

https://www.apachefriends.org/index.html

There was a SourceForge page that offer XAMPP 5.6.20 compiled for Linux 32-bit architecture, in which XAMPP 5.6.20 is compatible for 16.04 Ubuntu version.

wget "https://downloads.sourceforge.net/project/xampp/XAMPP%20Linux/5.6.20/xampp-linux-5.6.20-0-installer.run"
sudo su
chmod +x xampp-linux-5.6.20-0-installer.run
./xampp-linux-5.6.20-0-installer.run

Step 2: Make the installation package executable

We will install the package through the Ubuntu command line, The Terminal. In order to open the Terminal, either use the Dash or the Ctrl+Alt+T shortcut. After the Terminal is open, you need to move to your Downloads folder to access the file.

Move to the Downloads folder by using the following command:

$ cd /home/[username]/Downloads

The installation package you downloaded needs to be made executable before it can be used further. Run the following command for this purpose:

$ chmod 755 [package name]

Example:

$ chmod 755 xampp-linux-x64-7.2.10-0-installer.run

Now the install package is in an executable form.

Step 3: Confirm execute permission

It is important to verify if the package can be executed by the current user. The execute permission can be checked through the following command:

$ ls -l [package name]

Example:

$ ls -l xampp-linux-x64-7.2.10-0-installer.run

The -rwxr output shows that the file can be executed by the user whose name is also mentioned in the output.

Step 4: Launch the Setup Wizard

As a privileged root user, run the following command in order to launch the graphical setup wizard.

$ sudo ./[package name]

Example:

sudo ./xampp-linux-7.2.10-0-installer.run

mysql in not starting in XAMPP UBUNTU

1. backup your htdocs folder
2. backup your database folder '/opt/lampp/var/mysql'
3. check user on /opt/lampp/var/mysql $ ls -la
4. reinstall xampp full with delete data
5. copy paste your database folder to /opt/lampp/var/mysql
6. change user access after paste on /opt/lampp/var/mysql all file and folder

to check user on folder

$ cd /opt/lampp/var/mysql
$ ls -la

to change user on folder for all files and folder

$ sudo chown -R mysql:mysql *

and 1 file based on your computer ex:

$ sudo chown -R mysql:root emild-desktop.err

emild-desktop.err is log error of my pc

7. Copy Paste your htdocs folder on /opt/lampp

8. Restart lampp service.

   $ sudo /opt/lampp/lampp start

Chi tiết
https://vitux.com/how-to-install-xampp-on-your-ubuntu-18-04-lts-system/

xampp for puppylinux
( Chi tiết tham khảo tại đây )
 
I know it's a bit late answer but you could try any of these:
xampp-linux-x86_7.0.8-0_160628.squashfs https://1fichier.com/?1a6cja940l41fmehgwpd
xampp-linux-x64-7.3.3-1_190331a.squashfs https://1fichier.com/?mk31y4af6aqe0te3hilw
Just rename them to .SFS and mount them.

OR
xampp-linux-x86_7.0.8-0_160628.squashfs tại đây
xampp-linux-x64-7.3.3-1_190331a.squashfs tại đây
Just rename them to .SFS and mount them.

Đổi pas của root xong mà ko vào được thì dùng cách sau
https://www.youtube.com/watch?v=kea-2yFFrl0
Cac ung dung cua puppy
https://distro.ibiblio.org/puppylinux/pet_packages-3/
http://distro.ibiblio.org/puppylinux/pet_packages-4/
Tham khao them
https://community.vpssim.vn/viewtopic.php?t=59

LỆNH CẤU HÌNH BẢO MẬT CHO XAMPP

sudo /opt/lampp/lampp security