Composer安装

最近想学习一下yii2，但是composer一直安装失败，php -r "readfile('https://getcomposer.org/installer');" | php 执行会出现报错：

Warning: readfile(): SSL operation failed with code 1. OpenSSL Error messages:
error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify faile
d in Command line code on line 1

Warning: readfile(): Failed to enable crypto in Command line code on line 1

Warning: readfile(https://getcomposer.org/installer): failed to open stream: ope
ration failed in Command line code on line 1

而下载composer-setup.exe进行安装又会出现报错：

Connection Error [ERR_CONNECTION]: Unable to connect to getcomposer.org

Request to https://getcomposer.org/installer failed with errors:
SSL: Handshake timed out. Failed to enable crypto. Failed to open stream: operation failed

非常纠结。。

最终的方案：先在官网下载composer.phar（我也上传分享了一个，下载链接http://download.youkuaiyun.com/detail/st091zsc/9380118）

将composer.phar粘贴到php.exe的同级文件夹下（比如：D:\xampp\php），

新建composer.bat，内容是 

@ECHO OFF
php "%~dp0composer.phar" %*，

然后将php放到环境变量中，具体操作是右键点击“计算机”，选“属性”->“高级系统设置”->“环境变量”，可在用户变量中新建“path”，值为php.exe的路径，

即以上例子中的“D:\xampp\php”。

到此，安装已经完成，再打开cmd，输入“composer -v”，出现

则已经安装完成。