PHP7 : install ext-dom issue

For CentOS, RHEL, Fedora:

$ yum search php-xml
============================================================================================================ N/S matched: php-xml ============================================================================================================
php-xml.x86_64 : A module for PHP applications which use XML
php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php-xmlseclibs.noarch : PHP library for XML Security
php54-php-xml.x86_64 : A module for PHP applications which use XML
php54-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php55-php-xml.x86_64 : A module for PHP applications which use XML
php55-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php56-php-xml.x86_64 : A module for PHP applications which use XML
php56-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php70-php-xml.x86_64 : A module for PHP applications which use XML
php70-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php71-php-xml.x86_64 : A module for PHP applications which use XML
php71-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php72-php-xml.x86_64 : A module for PHP applications which use XML
php72-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol
php73-php-xml.x86_64 : A module for PHP applications which use XML
php73-php-xmlrpc.x86_64 : A module for PHP applications which use the XML-RPC protocol

Then select the php-xml version matching your php version:

# php -v
PHP 7.2.11 (cli) (built: Oct 10 2018 10:00:29) ( NTS )
Copyright (c) 1997-2018 The PHP Group
Zend Engine v3.2.0, Copyright (c) 1998-2018 Zend Technologies

# sudo yum install -y php72-php-xml.x86_64

First of all, read the warning! It says do not run composer as root! Secondly, you're probably using Xammp on your local which has the required php libraries as default.

But in your server you're missing ext-dom. php-xml has all the related packages you need. So, you can simply install it by running:

sudo apt-get update
sudo apt install php-xml

Most likely you are missing mbstring too. If you get the error, install this package as well with:

sudo apt-get install php-mbstring

Then run:

composer update
composer require cviebrock/eloquent-sluggable

sudo apt install php-xml will work but the thing is it will download the plugin for the latest PHP version.

If your PHP version is not the latest, then you can add version in it:

# PHP 7.1
sudo apt install php7.1-xml

# PHP 7.2:
sudo apt install php7.2-xml

# PHP 7.3
sudo apt install php7.3-xml


# PHP 7.4
sudo apt install php7.4-xml

# PHP 8
sudo apt install php-xml