誤差與作曲家在Ubuntu安裝laravel V 5.4

Question

哎安裝時出現錯誤laravel V-5.4

一個得到錯誤的：

的 「http://packagist.org/p/provider-2016%24e217873bdc8408956b33b1eb317ad1182d3a82fde9a746cc5e7def6135696f96.json」 文件無法下載（HTTP /1.1 500內部服務器錯誤） http://packagist.org無法完全加載，軟件包信息已從本地緩存中加載並可能已過期 安裝laravel/laravel（v5.5.0） - 安裝laravel/laravel（v5.5.0） ：從緩存中加載 在博客中創建項目 @php -r「file_exists（'。env'）||拷貝（ 'env.example'， '.ENV'）;」 加載作曲家庫與包信息 更新的依賴關係（包括需要-DEV）

無法解碼響應：zlib_decode（）：數據錯誤 重試與降級模式，檢查https://getcomposer.org/doc/articles/troubleshooting. MD＃降級模式的更多信息 你的要求不能被解析到一個安裝包集合。

Problem 1 
- phpunit/phpunit 6.4.1 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.4.0 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.3.1 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.3.0 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.2.4 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.2.3 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.2.2 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.2.1 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.2.0 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.1.4 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.1.3 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.1.2 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.1.1 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.1.0 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.9 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.8 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.7 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.6 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.5 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.4 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.3 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.2 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.13 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.12 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.11 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.10 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.1 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- phpunit/phpunit 6.0.0 requires ext-dom * -> the requested PHP extension dom is missing from your system. 
- Installation request for phpunit/phpunit ~6.0 -> satisfiable by phpunit/phpunit[6.0.0, 6.0.1, 6.0.10, 6.0.11, 6.0.12, 6.0.13, 6.0.2, 6.0.3, 6.0.4, 6.0.5, 6.0.6, 6.0.7, 6.0.8, 6.0.9, 6.1.0, 6.1.1, 6.1.2, 6.1.3, 6.1.4, 6.2.0, 6.2.1, 6.2.2, 6.2.3, 6.2.4, 6.3.0, 6.3.1, 6.4.0, 6.4.1]. 

請幫我完成了這個問題。我試過，但卻沒結果。

Answer 1

如果您使用的是PHP 7或更高版本，可以通過運行以下命令來安裝ext-dom：

sudo apt-get install php7.0-xml // for PHP 7 
sudo apt-get install php7.1-xml // for PHP 7