【注释：】本人原创，如需转载请注明来源链接！
通过安装Composer方式安装Yii
如果还没有安装 Composer，你可以按 getcomposer.org 中的方法安装。 在 Linux 和 Mac OS X 中，你可以运行如下命令：
curl -sS https://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer
步骤：
一、打开终端
二、安装composer：
1、终端输入：curl -sS https://getcomposer.org/installer | php
composer安装成功
2、终端输入：mv composer.phar /usr/local/bin/composer
将composer.phar移动到 /usr/local/bin/composer支持全局访问composer命令
3、验证方法：(注意：需要有访问权限，否则会提示没有权限访问)
输入：composer -v
三、安装Yii2
Composer 安装后，切换到一个可通过 Web 访问的目录，执行如下命令即可安装 Yii ：
composer global require "fxp/composer-asset-plugin:^1.2.0"
composer create-project --prefer-dist yiisoft/yii2-app-basic basic
第一条命令安装 Composer asset plugin， 它是通过 Composer 管理 bower 和 npm 包所必须的，此命令全局生效，一劳永逸。
第二条命令会将 Yii 安装在名为 basic 的目录中。如果你想使用其它目录名称，你可以选择其他目录名称。
1、终端输入：composer global require "fxp/composer-asset-plugin:^1.2.0"
如果你没有安装Gii该过程会提示你是否安装，安装即可（以下个人项目名称cqy，当然也可以修改成自己想要的项目名称）
2、终端输入：composer create-project --prefer-dist yiisoft/yii2-app-basic cqy
如果出现以下提示：
说明你权限不够，输入：sudo -s，提供root权限
有了权限之后重新输入命令，当进行到一半的时候发现需要token
token命令的话需要Github账号来获取
3、获取token
在使用github获取数据的时候，需要注册一个github账户
在账户 Account -->Setting 点击后页面刷新后， 点击 Personal access tokens， 点击Generate new Token按钮 生成token
获取到token后输入即可继续安装，如下：
Token (hidden):
Token stored successfully.
Package operations: 59 installs, 0 updates, 0 removals
- Installing yiisoft/yii2-composer (2.0.5): Downloading (100%)
- Installing swiftmailer/swiftmailer (v5.4.7): Downloading (100%)
- Installing bower-asset/jquery (2.2.4): Downloading (100%)
- Installing bower-asset/yii2-pjax (v2.0.6): Downloading (100%)
- Installing bower-asset/punycode (v1.3.2): Downloading (100%)
- Installing cebe/markdown (1.1.1): Downloading (100%)
- Installing ezyang/htmlpurifier (v4.9.2): Downloading (100%)
- Installing bower-asset/jquery.inputmask (3.3.5):Downloading (100%) )
- Installing yiisoft/yii2 (2.0.11.2): Downloading (100%)
- Installing yiisoft/yii2-swiftmailer (2.0.6): Downloading (100%)
- Installing bower-asset/bootstrap (v3.3.7): Downloading (100%)
- Installing yiisoft/yii2-bootstrap (2.0.6): Downloading (100%)
- Installing yiisoft/yii2-debug (2.0.9): Downloading (100%)
- Installing bower-asset/typeahead.js (v0.11.1): Downloading (100%)
- Installing phpspec/php-diff (v1.1.0): Downloading (100%)
- Installing yiisoft/yii2-gii (2.0.5): Downloading (100%)
- Installing fzaninotto/faker (v1.6.0): Downloading (100%)
- Installing yiisoft/yii2-faker (2.0.3): Downloading (100%)
- Installing psr/log (1.0.2): Downloading (100%)
- Installing symfony/debug (v3.2.7): Downloading (100%)
- Installing symfony/polyfill-mbstring (v1.3.0): Downloading (100%)
- Installing symfony/console (v3.2.7): Downloading (100%)
- Installing stecman/symfony-console-completion (0.7.0): Downloading (100%) - Installing sebastian/diff (1.4.1): Downloading (100%)
- Installing sebastian/recursion-context (2.0.0): Downloading (100%)
- Installing sebastian/exporter (2.0.0): Downloading (100%)
- Installing sebastian/comparator (1.2.4): Downloading (100%)
- Installing behat/gherkin (v4.4.5): Downloading (100%)
- Installing symfony/dom-crawler (v3.2.7): Downloading (100%)
- Installing symfony/css-selector (v3.2.7): Downloading (100%)
- Installing symfony/browser-kit (v3.2.7): Downloading (100%)
- Installing symfony/yaml (v3.2.7): Downloading (100%)
- Installing symfony/event-dispatcher (v3.2.7): Downloading (100%)
- Installing symfony/finder (v3.2.7): Downloading (100%)
- Installing psr/http-message (1.0.1): Downloading (100%)
- Installing guzzlehttp/psr7 (1.4.2): Downloading (100%)
- Installing sebastian/version (2.0.1): Downloading (100%)
- Installing sebastian/environment (2.0.0): Downloading (100%)
- Installing sebastian/code-unit-reverse-lookup (1.0.1): Downloading (100%) - Installing phpunit/php-token-stream (1.4.11): Downloading (100%)
- Installing phpunit/php-text-template (1.2.1): Downloading (100%)
- Installing phpunit/php-file-iterator (1.4.2): Downloading (100%)
- Installing phpunit/php-code-coverage (4.0.8): Downloading (100%)
- Installing sebastian/resource-operations (1.0.0): Downloading (100%) - Installing sebastian/object-enumerator (2.0.1): Downloading (100%)
- Installing sebastian/global-state (1.1.1): Downloading (100%)
- Installing doctrine/instantiator (1.0.5): Downloading (100%)
- Installing phpunit/phpunit-mock-objects (3.4.3):Downloading (100%) )
- Installing phpunit/php-timer (1.0.9): Downloading (100%)
- Installing webmozart/assert (1.2.0): Downloading (100%)
- Installing phpdocumentor/reflection-common (1.0): Downloading (100%) - Installing phpdocumentor/type-resolver (0.2.1): Downloading (100%)
- Installing phpdocumentor/reflection-docblock (3.1.1): Downloading (100%) - Installing phpspec/prophecy (v1.7.0): Downloading (100%)
- Installing myclabs/deep-copy (1.6.1): Downloading (100%)
- Installing phpunit/phpunit (5.7.19): Downloading (100%)
- Installing codeception/base (2.2.10): Downloading (100%)
- Installing codeception/verify (0.3.3): Downloading (100%)
- Installing codeception/specify (0.4.6): Downloading (100%)
symfony/console suggests installing symfony/filesystem ()
symfony/console suggests installing symfony/process ()
symfony/browser-kit suggests installing symfony/process ()
symfony/event-dispatcher suggests installing symfony/dependency-injection ()
symfony/event-dispatcher suggests installing symfony/http-kernel ()
phpunit/php-code-coverage suggests installing ext-xdebug (^2.5.1)
sebastian/global-state suggests installing ext-uopz (*)
phpunit/phpunit suggests installing phpunit/php-invoker (~1.1)
phpunit/phpunit suggests installing ext-xdebug (*)
codeception/base suggests installing flow/jsonpath (For using JSONPath in REST module)
codeception/base suggests installing phpseclib/phpseclib (for SFTP option in FTP Module)
codeception/base suggests installing league/factory-muffin (For DataFactory module)
codeception/base suggests installing league/factory-muffin-faker (For Faker support in DataFactory module)
codeception/base suggests installing symfony/phpunit-bridge (For phpunit-bridge support)
Writing lock file
Generating autoload files
> yii\composer\Installer::postCreateProject
chmod('runtime', 0777)...done.
chmod('web/assets', 0777)...done.
chmod('yii', 0755)...done.
安装成功！