Introduction to Composer

For programming beginners, you may have heard of composer, but you may not know what it is? how to install? The following PHP Chinese website composer tutorial column will explain in detail what composer is and the installation steps.

Introduction to Composer

Composer is a tool for PHP dependency management. It allows you to declare the libraries your project depends on and helps you complete the installation/update process.

Recommended: [composer tutorial]

Dependency Management

Composer is not a package manager like Yum or Apt. Although it will handle "packages" or libraries, its management of these packages and libraries is project-based. It will install these packages and libraries to a directory in your project (usually in the vendor folder). By default, it will not Will be installed globally. As a package manager, it also supports a global command called "global", which we can use to install global packages.

This way of managing extension packages is not the first or exclusive patent of Composer. In fact, Composer is largely inspired by node’s npm and ruby’s bundler.

Imagine:

You have a project that depends on several libraries;

Some libraries depend on other libraries.

Composer:

enables you to declare the libraries you depend on;

Find the versions provided by these libraries and need to be installed, and install them them (that is, downloaded into your project).

See the Basic Usage chapter for more information about "Dependency Declaration".

System Requirements

Composer requires PHP version 5.3.2 or above to run. You also need to make some settings and compilation flags for PHP, and you will receive all incompatibility warnings during installation.

To install the software from source instead of simply unzipping the zip file, you will need git, svn, fossil or hg depending on the version control tool used for the software.

Composer is multi-platform and runs well on Windows, Linux and OSX.

Installation - Linux / Unix /macOS

Download the Composer executable file

Composer provides a convenient installer, You can execute it directly from the command line. Free download address Or if you want to know more about this installer, here is the source code address GitHub.

These are two simple ways to install Composer, local installation (single project) and global installation (providing global system commands).

Local installation

In your project folder, run the installer. Check out the instructions on the installation page .

The installer will check the PHP configuration and download composer.phar to your (working directory) project folder. composer.phar is the Composer binary. It is a PHAR (PHP Archive) and can be run on the command line.

Now run php composer.phar to start Composer.

You can also add the option --install-dir to install Composer to the specified directory and add --filename to rename the downloaded file. When running the downloader with the following command:

php composer-setup.php --install-dir=bin --filename=composer

Then you can run php bin/composer to start Composer.

Global installation

You can place the composer.phar file anywhere. If you put it in your system's PATH, you can access it globally. On Unix-like systems, you can even use it without the php prefix.

After downloading and running the installer, you can move the composer.phar file to your command directory by running the following command:

mv composer.phar /usr/local/bin/composer

If you only want to install it for your user and avoid needing root privileges, you can use ~/local/bin instead of the default directory on some Linux distributions.

Note: If the above command fails due to permissions, you need to run it again using sudo.

Note: In some versions of OSX the /usr directory does not exist by default. If you receive the /usr/local/bin/composer: No such file or directory error, you must create the directory manually before running the mkdir -p /usr/local/bin command.

Note: For more information about changing the PATH environment variable, read the Wikipedia or use Google Search.

Now you only need to run the composer command to use Composer without entering php composer.phar.

Installation - Windows

Use the installer

This is the easiest way to install Composer on your machine .

Download and run Composer-Setup.exe, which will install the latest version of Composer and set the system environment variables, so you can use the composer command directly in any directory.

Note: Please close the current terminal window. Reopen a new terminal window for testing use: this is important because the path will only be loaded when the terminal is started.

Manual installation

Set the system environment variable PATH and run the installation command to download the composer.phar file:

Create a new file composer.bat in the same directory as composer.phar:

C:\bin>echo @php "%~dp0composer.phar" %*>composer.bat

If the path has not been set, add the directory to the PATH environment variable.

Close the current command line window and open a new command line window for testing:

C:\Users\username>composer -V Composer version 1.0.0 2016-01-10 20:34:53

Using Composer

Now that you have Composer installed, You're ready to use it! Continue below with a short presentation of the next chapter.

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