php -r "copy('https://install.phpcomposer.com/installer', 'composer-setup.php');"
php composer-setup.php # 安装完成后,小黑框会给出安装路径
php -r "unlink('composer-setup.php');"
将它复制或者剪切到php根目录下,也即是与php.exe平级的目录
# 内容 @php "%~dp0composer.phar" %*