Installing Yii
==============
You can install Yii in two ways, using [Composer](http://getcomposer.org/) or downloading an archive file.
The former is the preferred way as it allows you to install new [extensions](structure-extensions.md)
or update Yii by running a single command.
Installing via Composer
-----------------------
If you do not already have Composer installed, you may get it by following the instructions at
[getcomposer.org](https://getcomposer.org/download/), or simply
* on Linux or Mac, run the following commands:
```
curl -s http://getcomposer.org/installer | php
mv composer.phar /usr/local/bin/composer
```
* on Windows, download and run [Composer-Setup.exe](https://getcomposer.org/Composer-Setup.exe).
Please refer to the [Composer Documentation](https://getcomposer.org/doc/) if you encounter any
problems or want to learn more about the Composer usage.
With Composer installed, you can install Yii by running the following command under a Web accessible folder:
```
composer create-project --prefer-dist yiisoft/yii2-app-basic basic
```
The above command installs Yii as a directory named `basic`.
> Tip: If you want to install the latest development version of Yii, you may use the following command
which adds a `stability` option:
```
composer create-project --prefer-dist --stability=dev yiisoft/yii2-app-basic basic
```
Note that the development version of Yii should not be used for production as it may break your running code.
Installing from an Archive File
-------------------------------
Installing Yii from an archive file involves two steps:
1. Download the archive file from [yiiframework.com](http://www.yiiframework.com/download/yii2-basic);
2. Unpack the downloaded file to a Web accessible folder.
Other Installation Options
--------------------------
The above installation instructions show how to install Yii in terms of a basic Web application that works out of box.
It is a good start for small projects or if you just start learning Yii.
There are other installation options available:
* If you only want to install the core framework and would like to build an application from scratch,
you may follow the instructions as explained in [Building Application from Scratch](tutorial-start-from-scratch.md).
* If you want to start with a more sophisticated application that supports team development environment,
you may consider [Advanced Application Template](tutorial-advanced-app.md).
Verifying Installation
----------------------
After installation, you can use your browser to access the installed Yii application with the following URL,
assuming you have installed Yii in a directory named `basic` that is under the document root of your Web server
and the server name is `hostname`,
```
http://hostname/basic/web/index.php
```
You should see the above "Congratulations!" page in your browser. If not, please check if your PHP installation satisfies
Yii's requirements by using one of the following approaches:
* Use a browser to access the URL `http://hostname/basic/requirements.php`
* Run the following commands:
```
cd basic
php requirements.php
```
You should configure your PHP installation so that it meets the minimum requirement of Yii.
In general, you should have PHP 5.4 or above. And you should install
the [PDO PHP Extension](http://www.php.net/manual/en/pdo.installation.php) and a corresponding database driver
(such as `pdo_mysql` for MySQL databases), if your application needs a database.
Configuring Web Servers
-----------------------
> Info: You may skip this sub-section for now if you are just testing driving Yii with no intention
of deploying it to a production server.
The application installed according to the above instructions should work out of box with either
an [Apache HTTP server](http://httpd.apache.org/) or an [Nginx HTTP server](http://nginx.org/), on
either Windows or Linux.
On a production server, you may want to configure your Web server so that the application can be accessed
via the URL `http://hostname/index.php` instead of `http://hostname/basic/web/index.php`. This
requires pointing the document root of your Web server to the `basic/web` folder. And you may also
want to hide `index.php` from the URL, as described in the [URL Parsing and Generation](runtime-url-handling.md) section.
In this subsection, we will show how to configure your Apache or Nginx server to achieve these goals.
> Info: By setting `basic/web` as the document root, you also prevent end users from accessing
your private application code and sensitive data files that are stored in the sibling directories
of `basic/web`. This makes your application more secure.
> Info: If your application will run in a shared hosting environment where you do not have the permission
to modify its Web server setting, you may adjust the structure of your application. Please refer to
the [Shared Hosting Environment](tutorial-shared-hosting.md) section for more details.
### Recommended Apache Configuration
Use the following configuration in Apache's `httpd.conf` file or within a virtual host configuration. Note that you
should replace `path/to/basic/web` with the actual path of `basic/web`.
```
# Set document root to be "basic/web"
DocumentRoot "path/to/basic/web"
RewriteEngine on
# If a directory or a file exists, use the request directly
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
# Otherwise forward the request to index.php
RewriteRule . index.php
# ...other settings...
```
### Recommended Nginx Configuration
You should have installed PHP as an [FPM SAPI](http://php.net/install.fpm) for [Nginx](http://wiki.nginx.org/).
Use the following Nginx configuration and replace `path/to/basic/web` with the actual path of `basic/web`.
```
server {
charset utf-8;
client_max_body_size 128M;
listen 80; ## listen for ipv4
#listen [::]:80 default_server ipv6only=on; ## listen for ipv6
server_name mysite.local;
root /path/to/basic/web;
index index.php;
access_log /path/to/project/log/access.log main;
error_log /path/to/project/log/error.log;
location / {
# Redirect everything that isn't a real file to index.php
try_files $uri $uri/ /index.php?$args;
}
# uncomment to avoid processing of calls to non-existing static files by Yii
#location ~ \.(js|css|png|jpg|gif|swf|ico|pdf|mov|fla|zip|rar)$ {
# try_files $uri =404;
#}
#error_page 404 /404.html;
location ~ \.php$ {
include fastcgi.conf;
fastcgi_pass 127.0.0.1:9000;
#fastcgi_pass unix:/var/run/php5-fpm.sock;
}
location ~ /\.(ht|svn|git) {
deny all;
}
}
```
When using this configuration, you should set `cgi.fix_pathinfo=0` in the `php.ini` file
in order to avoid many unnecessary system `stat()` calls.
Also note that when running an HTTPS server you need to add `fastcgi_param HTTPS on;` so that Yii
can properly detect if a connection is secure.