2019独角兽企业重金招聘Python工程师标准>>> 
我把它放在系统的PATH目录中，这样就能在全局访问它。
curl -sS https://getcomposer.org/installer | php mv composer.phar /usr/local/bin/composer
注意：如果上诉命令因为权限执行失败， 请使用 sudo 再次尝试运行 mv那行命令。
输入命令：composer -V
Composer version 1.0-dev (feefd51565bb8ead38e355b9e501685b5254d
liuxiaoqiang@liuxiaoqiang /var/www $ sudo curl -sS https://getcomposer.org/installer | php
[sudo] password for liuxiaoqiang:
All settings correct for using Composer
Downloading...
Composer successfully installed to: /var/www/composer.phar
Use it: php composer.phar
liuxiaoqiang@liuxiaoqiang /var/www $ sudo mv composer.phar /usr/local/bin/composer
liuxiaoqiang@liuxiaoqiang /var/www $ composer -V
Composer version 1.0-dev (24f04f7dbfb7321fda1a973cf9af41684322cf01) 2016-03-14 11:34:00
```
官网提供的下载包
下载 Laravel 一键安装包
安装 Composer 或通过 Composer 下载 Laravel 的依赖包时都可能被墙，为了方便大家学习和开发 Laravel 应用，Laravel 中文网已经提供了 Laravel 各个版本的一键安装包。这些一键安装包都已经集成了所有依赖（也就是已经执行过 composer install 了，vendor 目录已经就绪）。
下载地址：http://www.golaravel.com/download/
里面有一个vendor包
在网站目录执行composer install，产生的文件和这个是一个道理，具体代码如下
```
liuxiaoqiang@liuxiaoqiang ~/tfan/jifen/jifen $ composer install
Loading composer repositories with package information
Installing dependencies (including require-dev) from lock file
- Installing jakub-onderka/php-console-color (0.1)
Downloading: 100%
- Installing vlucas/phpdotenv (v2.2.0)
Downloading: 100%
- Installing symfony/polyfill-mbstring (v1.1.0)
Downloading: 100%
- Installing symfony/var-dumper (v3.0.3)
Downloading: 100%
- Installing symfony/translation (v3.0.3)
Downloading: 100%
- Installing symfony/routing (v3.0.3)
Downloading: 100%
- Installing symfony/process (v3.0.3)
Downloading: 100%
- Installing symfony/polyfill-util (v1.1.0)
Downloading: 100%
- Installing symfony/polyfill-php56 (v1.1.0)
Downloading: 100%
- Installing symfony/http-foundation (v3.0.3)
Downloading: 100%
- Installing symfony/event-dispatcher (v3.0.3)
Downloading: 100%
- Installing psr/log (1.0.0)
Downloading: 100%
- Installing symfony/debug (v3.0.3)
Downloading: 100%
- Installing symfony/http-kernel (v3.0.3)
Downloading: 100%
- Installing symfony/finder (v3.0.3)
Downloading: 100%
- Installing symfony/console (v3.0.3)
Downloading: 100%
- Installing swiftmailer/swiftmailer (v5.4.1)
Downloading: 100%
- Installing nikic/php-parser (v2.0.1)
Downloading: 100%
- Installing jakub-onderka/php-console-highlighter (v0.3.2)
Downloading: 100%
- Installing dnoegel/php-xdg-base-dir (0.1)
Downloading: 100%
- Installing psy/psysh (v0.7.1)
Downloading: 100%
- Installing paragonie/random_compat (v1.2.1)
Downloading: 100%
- Installing nesbot/carbon (1.21.0)
Downloading: 100%
- Installing mtdowling/cron-expression (v1.1.0)
Downloading: 100%
- Installing monolog/monolog (1.18.0)
Downloading: 100%
- Installing league/flysystem (1.0.18)
Loading from cache
- Installing jeremeamia/superclosure (2.2.0)
Downloading: 100%
- Installing doctrine/inflector (v1.1.0)
Downloading: 100%
- Installing classpreloader/classpreloader (3.0.0)
Downloading: 100%
- Installing laravel/framework (v5.2.22)
Downloading: 100%
- Installing fzaninotto/faker (v1.5.0)
Downloading: 100%
- Installing hamcrest/hamcrest-php (v1.2.2)
Downloading: 100%
- Installing mockery/mockery (0.9.4)
Downloading: 100%
- Installing phpdocumentor/reflection-docblock (2.0.4)
Downloading: 100%
- Installing phpunit/php-token-stream (1.4.8)
Downloading: 100%
- Installing symfony/yaml (v3.0.3)
Downloading: 100%
- Installing sebastian/version (1.0.6)
Downloading: 100%
- Installing sebastian/global-state (1.1.1)
Downloading: 100%
- Installing sebastian/recursion-context (1.0.2)
Downloading: 100%
- Installing sebastian/exporter (1.2.1)
Downloading: 100%
- Installing sebastian/environment (1.3.5)
Downloading: 100%
- Installing sebastian/diff (1.4.1)
Downloading: 100%
- Installing sebastian/comparator (1.2.0)
Downloading: 100%
- Installing phpunit/php-text-template (1.2.1)
Downloading: 100%
- Installing doctrine/instantiator (1.0.5)
Downloading: 100%
- Installing phpunit/phpunit-mock-objects (2.3.8)
Downloading: 100%
- Installing phpunit/php-timer (1.0.7)
Downloading: 100%
- Installing phpunit/php-file-iterator (1.4.1)
Downloading: 100%
- Installing phpunit/php-code-coverage (2.2.4)
Downloading: 100%
- Installing phpspec/prophecy (v1.6.0)
Downloading: 100%
- Installing phpunit/phpunit (4.8.23)
Downloading: 100%
- Installing symfony/css-selector (v3.0.3)
Downloading: 100%
- Installing symfony/dom-crawler (v3.0.3)
Downloading: 100%
symfony/var-dumper suggests installing ext-symfony_debug ()
symfony/translation suggests installing symfony/config ()
symfony/routing suggests installing doctrine/annotations (For using the annotation loader)
symfony/routing suggests installing symfony/config (For using the all-in-one router or any loader)
symfony/routing suggests installing symfony/dependency-injection (For loading routes from a service)
symfony/routing suggests installing symfony/expression-language (For using expression matching)
symfony/event-dispatcher suggests installing symfony/dependency-injection ()
symfony/http-kernel suggests installing symfony/browser-kit ()
symfony/http-kernel suggests installing symfony/class-loader ()
symfony/http-kernel suggests installing symfony/config ()
symfony/http-kernel suggests installing symfony/dependency-injection ()
psy/psysh suggests installing ext-pdo-sqlite (The doc command requires SQLite to work.)
paragonie/random_compat suggests installing ext-libsodium (Provides a modern crypto API that can be used to generate random bytes.)
monolog/monolog suggests installing aws/aws-sdk-php (Allow sending log messages to AWS services like DynamoDB)
monolog/monolog suggests installing doctrine/couchdb (Allow sending log messages to a CouchDB server)
monolog/monolog suggests installing ext-amqp (Allow sending log messages to an AMQP server (1.0+ required))
monolog/monolog suggests installing ext-mongo (Allow sending log messages to a MongoDB server)
monolog/monolog suggests installing graylog2/gelf-php (Allow sending log messages to a GrayLog2 server)
monolog/monolog suggests installing mongodb/mongodb (Allow sending log messages to a MongoDB server via PHP Driver)
monolog/monolog suggests installing php-console/php-console (Allow sending log messages to Google Chrome)
monolog/monolog suggests installing raven/raven (Allow sending log messages to a Sentry server)
monolog/monolog suggests installing rollbar/rollbar (Allow sending log messages to Rollbar)
monolog/monolog suggests installing ruflin/elastica (Allow sending log messages to an Elastic Search server)
monolog/monolog suggests installing videlalvaro/php-amqplib (Allow sending log messages to an AMQP server using php-amqplib)
league/flysystem suggests installing league/flysystem-aws-s3-v2 (Allows you to use S3 storage with AWS SDK v2)
league/flysystem suggests installing league/flysystem-aws-s3-v3 (Allows you to use S3 storage with AWS SDK v3)
league/flysystem suggests installing league/flysystem-azure (Allows you to use Windows Azure Blob storage)
league/flysystem suggests installing league/flysystem-cached-adapter (Flysystem adapter decorator for metadata caching)
league/flysystem suggests installing league/flysystem-copy (Allows you to use Copy.com storage)
league/flysystem suggests installing league/flysystem-dropbox (Allows you to use Dropbox storage)
league/flysystem suggests installing league/flysystem-eventable-filesystem (Allows you to use EventableFilesystem)
league/flysystem suggests installing league/flysystem-rackspace (Allows you to use Rackspace Cloud Files)
league/flysystem suggests installing league/flysystem-sftp (Allows you to use SFTP server storage via phpseclib)
league/flysystem suggests installing league/flysystem-webdav (Allows you to use WebDAV storage)
league/flysystem suggests installing league/flysystem-ziparchive (Allows you to use ZipArchive adapter)
laravel/framework suggests installing aws/aws-sdk-php (Required to use the SQS queue driver and SES mail driver (~3.0).)
laravel/framework suggests installing doctrine/dbal (Required to rename columns and drop SQLite columns (~2.4).)
laravel/framework suggests installing guzzlehttp/guzzle (Required to use the Mailgun and Mandrill mail drivers and the ping methods on schedules (~5.3|~6.0).)
laravel/framework suggests installing league/flysystem-aws-s3-v3 (Required to use the Flysystem S3 driver (~1.0).)
laravel/framework suggests installing league/flysystem-rackspace (Required to use the Flysystem Rackspace driver (~1.0).)
laravel/framework suggests installing pda/pheanstalk (Required to use the beanstalk queue driver (~3.0).)
laravel/framework suggests installing predis/predis (Required to use the redis cache and queue drivers (~1.0).)
laravel/framework suggests installing pusher/pusher-php-server (Required to use the Pusher broadcast driver (~2.0).)
fzaninotto/faker suggests installing ext-intl (*)
phpdocumentor/reflection-docblock suggests installing dflydev/markdown (~1.0)
phpdocumentor/reflection-docblock suggests installing erusev/parsedown (~1.0)
sebastian/global-state suggests installing ext-uopz (*)
phpunit/php-code-coverage suggests installing ext-xdebug (>=2.2.1)
phpunit/phpunit suggests installing phpunit/php-invoker (~1.1)
Generating autoload files
> php artisan clear-compiled
> php artisan optimize
Generating optimized class loader
Compiling common classes
liuxiaoqiang@liuxiaoqiang ~/tfan/jifen/jifen $
```