[Seld \ JsonLint \ ParsingException]

Question

我试图在laravel项目中安装dompdf，但出现以下错误。请帮我。 在cmd中运行的代码，给出了laravel项目

  

撰写者需要barryvdh / laravel-dompdf    错误在这里给出。请帮助我，错误在哪里。我的json有效，我已经在jsonlint.com上进行了检查

C:\xampp\htdocs\prolearning>composer require barryvdh/laravel-dompdf
The "https://packagist.org/packages.json" file could not be downloaded: php_netw
ork_getaddresses: getaddrinfo failed: No such host is known.
failed to open stream: php_network_getaddresses: getaddrinfo failed: No such hos
t is known.
https://packagist.org could not be fully loaded, package information was loaded
from the local cache and may be out of date



  [Seld\JsonLint\ParsingException]

  "C:/Users/ISRP/AppData/Local/Composer/repo/https---packagist.org/packages.json
" does not contain valid JSON
  Parse error on line 1:

  \\\\\\\\\\\\\\\\\\\\

  ^

  Expected one of: 'STRING', 'NUMBER', 'NULL', 'TRUE', 'FALSE', '{', '['




require [--dev] [--prefer-source] [--prefer-dist] [--no-progress] [--no-suggest]
 [--no-update] [--no-scripts] [--update-no-dev] [--update-with-dependencies] [--
update-with-all-dependencies] [--ignore-platform-reqs] [--prefer-stable] [--pref
er-lowest] [--sort-packages] [-o|--optimize-autoloader] [-a|--classmap-authorita
tive] [--apcu-autoloader] [--] [<packages>]...