composer download and install

linux/mac os

curl -sS https://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer

windows

• 1, php set global command (Advanced System Settings php.exe path Add folder path)
• 2, php.ini

extension=php_openssl.dll    // 去点前面的;

• 3 download

https://getcomposer.org/download/   
进入页面自己下载

• 4 Double-composer-setup.exe (installation fool)