1、下载composer
php -r "copy('https://install.phpcomposer.com/installer', 'composer-setup.php');"
2、执行安装
php composer-setup.php
3、将composer放到系统环境变量中
mv composer.phar /usr/local/bin/composer
4、修改镜像为阿里镜像
composer config -g repo.packagist composer https://mirrors.aliyun.com/composer/
注意:第四步不能使用root执行。会报错
Do not run Composer as root/super user! See https://getcomposer.org/root for details