centos7安装composer

1. 下载composer.phar

// 如果是网络原因失败，多试几次
curl -sS https://getcomposer.org/installer | php

2. 把composer.phar移动到环境下让其变成可执行

mv composer.phar /usr/local/bin/composer

3. 测试

composer -v

4. 修改镜像地址

composer config -g repo.packagist composer https://packagist.phpcomposer.com