composer/doc/03-cli.md

# Command-line interface / Commands

You've already learned how to use the command-line interface to do some
things. This chapter documents all the available commands.

To get help from the command-line, simply call `composer` or `composer list`
to see the complete list of commands, then `--help` combined with any of those
can give you more information.

As Composer uses [symfony/console](https://github.com/symfony/console) you can call commands by short name if it's not ambiguous.
```sh
composer dump
```
calls `composer dump-autoload`.

## Global Options

The following options are available with every command:

* **--verbose (-v):** Increase verbosity of messages.
* **--help (-h):** Display help information.
* **--quiet (-q):** Do not output any message.
* **--no-interaction (-n):** Do not ask any interactive question.
* **--no-plugins:** Disables plugins.
* **--working-dir (-d):** If specified, use the given directory as working directory.
* **--profile:** Display timing and memory usage information
* **--ansi:** Force ANSI output.
* **--no-ansi:** Disable ANSI output.
* **--version (-V):** Display this application version.

## Process Exit Codes

* **0:** OK
* **1:** Generic/unknown error code
* **2:** Dependency solving error code

## init

In the [Libraries](02-libraries.md) chapter we looked at how to create a
`composer.json` by hand. There is also an `init` command available that makes
it a bit easier to do this.

When you run the command it will interactively ask you to fill in the fields,
while using some smart defaults.

```sh
php composer.phar init
```

### Options

* **--name:** Name of the package.
* **--description:** Description of the package.
* **--author:** Author name of the package.
* **--type:** Type of package.
* **--homepage:** Homepage of the package.
* **--require:** Package to require with a version constraint. Should be
  in format `foo/bar:1.0.0`.
* **--require-dev:** Development requirements, see **--require**.
* **--stability (-s):** Value for the `minimum-stability` field.
* **--license (-l):** License of package.
* **--repository:** Provide one (or more) custom repositories. They will be stored
  in the generated composer.json, and used for auto-completion when prompting for
  the list of requires. Every repository can be either an HTTP URL pointing
  to a `composer` repository or a JSON string which similar to what the
  [repositories](04-schema.md#repositories) key accepts.

## install

The `install` command reads the `composer.json` file from the current
directory, resolves the dependencies, and installs them into `vendor`.

```sh
php composer.phar install
```

If there is a `composer.lock` file in the current directory, it will use the
exact versions from there instead of resolving them. This ensures that
everyone using the library will get the same versions of the dependencies.

If there is no `composer.lock` file, Composer will create one after dependency
resolution.

### Options

* **--prefer-source:** There are two ways of downloading a package: `source`
  and `dist`. For stable versions Composer will use the `dist` by default.
  The `source` is a version control repository. If `--prefer-source` is
  enabled, Composer will install from `source` if there is one. This is
  useful if you want to make a bugfix to a project and get a local git
  clone of the dependency directly.
* **--prefer-dist:** Reverse of `--prefer-source`, Composer will install
  from `dist` if possible. This can speed up installs substantially on build
  servers and other use cases where you typically do not run updates of the
  vendors. It is also a way to circumvent problems with git if you do not
  have a proper setup.
* **--dry-run:** If you want to run through an installation without actually
  installing a package, you can use `--dry-run`. This will simulate the
  installation and show you what would happen.
* **--dev:** Install packages listed in `require-dev` (this is the default behavior).
* **--no-dev:** Skip installing packages listed in `require-dev`. The autoloader
  generation skips the `autoload-dev` rules.
* **--no-autoloader:** Skips autoloader generation.
* **--no-scripts:** Skips execution of scripts defined in `composer.json`.
* **--no-progress:** Removes the progress display that can mess with some
  terminals or scripts which don't handle backspace characters.
* **--no-suggest:** Skips suggested packages in the output.
* **--optimize-autoloader (-o):** Convert PSR-0/4 autoloading to classmap to get a faster
  autoloader. This is recommended especially for production, but can take
  a bit of time to run so it is currently not done by default.
* **--classmap-authoritative (-a):** Autoload classes from the classmap only.
  Implicitly enables `--optimize-autoloader`.
* **--apcu-autoloader:** Use APCu to cache found/not-found classes.
* **--ignore-platform-reqs:** ignore `php`, `hhvm`, `lib-*` and `ext-*`
  requirements and force the installation even if the local machine does not
  fulfill these. See also the [`platform`](06-config.md#platform) config option.

## update

In order to get the latest versions of the dependencies and to update the
`composer.lock` file, you should use the `update` command. This command is also
aliased as `upgrade` as it does the same as `upgrade` does if you are thinking
of `apt-get` or similar package managers.

```sh
php composer.phar update
```

This will resolve all dependencies of the project and write the exact versions
into `composer.lock`.

If you just want to update a few packages and not all, you can list them as such:

```sh
php composer.phar update vendor/package vendor/package2
```

You can also use wildcards to update a bunch of packages at once:

```sh
php composer.phar update vendor/*
```

### Options

* **--prefer-source:** Install packages from `source` when available.
* **--prefer-dist:** Install packages from `dist` when available.
* **--dry-run:** Simulate the command without actually doing anything.
* **--dev:** Install packages listed in `require-dev` (this is the default behavior).
* **--no-dev:** Skip installing packages listed in `require-dev`. The autoloader generation skips the `autoload-dev` rules.
* **--lock:** Only updates the lock file hash to suppress warning about the
  lock file being out of date.
* **--no-autoloader:** Skips autoloader generation.
* **--no-scripts:** Skips execution of scripts defined in `composer.json`.
* **--no-progress:** Removes the progress display that can mess with some
  terminals or scripts which don't handle backspace characters.
* **--no-suggest:** Skips suggested packages in the output.
* **--with-dependencies:** Add also dependencies of whitelisted packages to the whitelist, except those that are root requirements.
* **--with-all-dependencies:** Add also all dependencies of whitelisted packages to the whitelist, including those that are root requirements.
* **--optimize-autoloader (-o):** Convert PSR-0/4 autoloading to classmap to get a faster
  autoloader. This is recommended especially for production, but can take
  a bit of time to run so it is currently not done by default.
* **--classmap-authoritative (-a):** Autoload classes from the classmap only.
  Implicitly enables `--optimize-autoloader`.
* **--apcu-autoloader:** Use APCu to cache found/not-found classes.
* **--ignore-platform-reqs:** ignore `php`, `hhvm`, `lib-*` and `ext-*`
  requirements and force the installation even if the local machine does not
  fulfill these. See also the [`platform`](06-config.md#platform) config option.
* **--prefer-stable:** Prefer stable versions of dependencies.
* **--prefer-lowest:** Prefer lowest versions of dependencies. Useful for testing minimal
  versions of requirements, generally used with `--prefer-stable`.
* **--interactive:** Interactive interface with autocompletion to select the packages to update.
* **--root-reqs:** Restricts the update to your first degree dependencies.

## require

The `require` command adds new packages to the `composer.json` file from
the current directory. If no file exists one will be created on the fly.

```sh
php composer.phar require
```

After adding/changing the requirements, the modified requirements will be
installed or updated.

If you do not want to choose requirements interactively, you can just pass them
to the command.

```sh
php composer.phar require vendor/package:2.* vendor/package2:dev-master
```

### Options

* **--dev:** Add packages to `require-dev`.
* **--prefer-source:** Install packages from `source` when available.
* **--prefer-dist:** Install packages from `dist` when available.
* **--no-progress:** Removes the progress display that can mess with some
  terminals or scripts which don't handle backspace characters.
* **--no-suggest:** Skips suggested packages in the output.
* **--no-update:** Disables the automatic update of the dependencies.
* **--no-scripts:** Skips execution of scripts defined in `composer.json`.
* **--update-no-dev:** Run the dependency update with the `--no-dev` option.
* **--update-with-dependencies:** Also update dependencies of the newly required packages, except those that are root requirements.
* **--update-with-all-dependencies:** Also update dependencies of the newly required packages, including those that are root requirements.
* **--ignore-platform-reqs:** ignore `php`, `hhvm`, `lib-*` and `ext-*`
  requirements and force the installation even if the local machine does not
  fulfill these. See also the [`platform`](06-config.md#platform) config option.
* **--prefer-stable:** Prefer stable versions of dependencies.
* **--prefer-lowest:** Prefer lowest versions of dependencies. Useful for testing minimal
  versions of requirements, generally used with `--prefer-stable`.
* **--sort-packages:** Keep packages sorted in `composer.json`.
* **--optimize-autoloader (-o):** Convert PSR-0/4 autoloading to classmap to
  get a faster autoloader. This is recommended especially for production, but
  can take a bit of time to run so it is currently not done by default.
* **--classmap-authoritative (-a):** Autoload classes from the classmap only.
  Implicitly enables `--optimize-autoloader`.
* **--apcu-autoloader:** Use APCu to cache found/not-found classes.


## remove

The `remove` command removes packages from the `composer.json` file from
the current directory.

```sh
php composer.phar remove vendor/package vendor/package2
```

After removing the requirements, the modified requirements will be
uninstalled.

### Options
* **--dev:** Remove packages from `require-dev`.
* **--no-progress:** Removes the progress display that can mess with some
  terminals or scripts which don't handle backspace characters.
* **--no-update:** Disables the automatic update of the dependencies.
* **--no-scripts:** Skips execution of scripts defined in `composer.json`.
* **--update-no-dev:** Run the dependency update with the --no-dev option.
* **--update-with-dependencies:** Also update dependencies of the removed packages.
* **--ignore-platform-reqs:** ignore `php`, `hhvm`, `lib-*` and `ext-*`
  requirements and force the installation even if the local machine does not
  fulfill these. See also the [`platform`](06-config.md#platform) config option.
* **--optimize-autoloader (-o):** Convert PSR-0/4 autoloading to classmap to
  get a faster autoloader. This is recommended especially for production, but
  can take a bit of time to run so it is currently not done by default.
* **--classmap-authoritative (-a):** Autoload classes from the classmap only.
  Implicitly enables `--optimize-autoloader`.
* **--apcu-autoloader:** Use APCu to cache found/not-found classes.

## global

The global command allows you to run other commands like `install`, `require`
or `update` as if you were running them from the [COMPOSER_HOME](#composer-home)
directory.

This is merely a helper to manage a project stored in a central location that
can hold CLI tools or Composer plugins that you want to have available everywhere.

This can be used to install CLI utilities globally. Here is an example:

```sh
php composer.phar global require fabpot/php-cs-fixer
```

Now the `php-cs-fixer` binary is available globally. Just make sure your global
[vendor binaries](articles/vendor-binaries.md) directory is in your `$PATH`
environment variable, you can get its location with the following command :

```sh
php composer.phar global config bin-dir --absolute
```

If you wish to update the binary later on you can just run a global update:

```sh
php composer.phar global update
```

## search

The search command allows you to search through the current project's package
repositories. Usually this will be just packagist. You simply pass it the
terms you want to search for.

```sh
php composer.phar search monolog
```

You can also search for more than one term by passing multiple arguments.

### Options

* **--only-name (-N):** Search only in name.
* **--type (-t):** Search for a specific package type.

## show

To list all of the available packages, you can use the `show` command.

```sh
php composer.phar show
```

To filter the list you can pass a package mask using wildcards.

```sh
php composer.phar show monolog/*

monolog/monolog 1.19.0 Sends your logs to files, sockets, inboxes, databases and various web services
```

If you want to see the details of a certain package, you can pass the package
name.

```sh
php composer.phar show monolog/monolog

name     : monolog/monolog
versions : master-dev, 1.0.2, 1.0.1, 1.0.0, 1.0.0-RC1
type     : library
names    : monolog/monolog
source   : [git] https://github.com/Seldaek/monolog.git 3d4e60d0cbc4b888fe5ad223d77964428b1978da
dist     : [zip] https://github.com/Seldaek/monolog/zipball/3d4e60d0cbc4b888fe5ad223d77964428b1978da 3d4e60d0cbc4b888fe5ad223d77964428b1978da
license  : MIT

autoload
psr-0
Monolog : src/

requires
php >=5.3.0
```

You can even pass the package version, which will tell you the details of that
specific version.

```sh
php composer.phar show monolog/monolog 1.0.2
```

### Options

* **--all :** List all packages available in all your repositories.
* **--installed (-i):** List the packages that are installed (this is enabled by default, and deprecated).
* **--platform (-p):** List only platform packages (php & extensions).
* **--available (-a):** List available packages only.
* **--self (-s):** List the root package info.
* **--name-only (-N):** List package names only.
* **--path (-P):** List package paths.
* **--tree (-t):** List your dependencies as a tree. If you pass a package name it will show the dependency tree for that package.
* **--latest (-l):** List all installed packages including their latest version.
* **--outdated (-o):** Implies --latest, but this lists *only* packages that have a newer version available.
* **--minor-only (-m):** Use with --latest. Only shows packages that have minor SemVer-compatible updates.
* **--direct (-D):** Restricts the list of packages to your direct dependencies.
* **--strict:** Return a non-zero exit code when there are outdated packages.
* **--format (-f):** Lets you pick between text (default) or json output format.

## outdated

The `outdated` command shows a list of installed packages that have updates available,
including their current and latest versions. This is basically an alias for
`composer show -lo`.

The color coding is as such:

- **green (=)**: Dependency is in the latest version and is up to date.
- **yellow (~)**: Dependency has a new version available that includes backwards compatibility breaks according to semver, so upgrade when
  you can but it may involve work.
- **red (!)**: Dependency has a new version that is semver-compatible and you should upgrade it.

### Options

* **--all (-a):** Show all packages, not just outdated (alias for `composer show -l`).
* **--direct (-D):** Restricts the list of packages to your direct dependencies.
* **--strict:** Returns non-zero exit code if any package is outdated.
* **--minor-only (-m):** Only shows packages that have minor SemVer-compatible updates.
* **--format (-f):** Lets you pick between text (default) or json output format.

## browse / home

The `browse` (aliased to `home`) opens a package's repository URL or homepage
in your browser.

### Options

* **--homepage (-H):** Open the homepage instead of the repository URL.
* **--show (-s):** Only show the homepage or repository URL.

## suggests

Lists all packages suggested by currently installed set of packages. You can
optionally pass one or multiple package names in the format of `vendor/package`
to limit output to suggestions made by those packages only.

Use the `--by-package` or `--by-suggestion` flags to group the output by
the package offering the suggestions or the suggested packages respectively.

Use the `--verbose (-v)` flag to display the suggesting package and the suggestion reason.
This implies `--by-package --by-suggestion`, showing both lists.

### Options

* **--by-package:** Groups output by suggesting package.
* **--by-suggestion:** Groups output by suggested package.
* **--no-dev:** Excludes suggestions from `require-dev` packages.

## depends (why)

The `depends` command tells you which other packages depend on a certain
package. As with installation `require-dev` relationships are only considered
for the root package.

```sh
php composer.phar depends doctrine/lexer
 doctrine/annotations v1.2.7 requires doctrine/lexer (1.*)
 doctrine/common      v2.6.1 requires doctrine/lexer (1.*)
```

You can optionally specify a version constraint after the package to limit the
search.

Add the `--tree` or `-t` flag to show a recursive tree of why the package is
depended upon, for example:

```sh
php composer.phar depends psr/log -t
psr/log 1.0.0 Common interface for logging libraries
|- aboutyou/app-sdk 2.6.11 (requires psr/log 1.0.*)
|  `- __root__ (requires aboutyou/app-sdk ^2.6)
|- monolog/monolog 1.17.2 (requires psr/log ~1.0)
|  `- laravel/framework v5.2.16 (requires monolog/monolog ~1.11)
|     `- __root__ (requires laravel/framework ^5.2)
`- symfony/symfony v3.0.2 (requires psr/log ~1.0)
   `- __root__ (requires symfony/symfony ^3.0)
```

### Options

* **--recursive (-r):** Recursively resolves up to the root package.
* **--tree (-t):** Prints the results as a nested tree, implies -r.

## prohibits (why-not)

The `prohibits` command tells you which packages are blocking a given package
from being installed. Specify a version constraint to verify whether upgrades
can be performed in your project, and if not why not. See the following
example:

```sh
php composer.phar prohibits symfony/symfony 3.1
 laravel/framework v5.2.16 requires symfony/var-dumper (2.8.*|3.0.*)
```

Note that you can also specify platform requirements, for example to check
whether you can upgrade your server to PHP 8.0:

```sh
php composer.phar prohibits php:8
 doctrine/cache        v1.6.0 requires php (~5.5|~7.0)
 doctrine/common       v2.6.1 requires php (~5.5|~7.0)
 doctrine/instantiator 1.0.5  requires php (>=5.3,<8.0-DEV)
```

As with `depends` you can request a recursive lookup, which will list all
packages depending on the packages that cause the conflict.

### Options

* **--recursive (-r):** Recursively resolves up to the root package.
* **--tree (-t):** Prints the results as a nested tree, implies -r.

## validate

You should always run the `validate` command before you commit your
`composer.json` file, and before you tag a release. It will check if your
`composer.json` is valid.

```sh
php composer.phar validate
```

### Options

* **--no-check-all:** Do not emit a warning if requirements in `composer.json` use unbound version constraints.
* **--no-check-lock:** Do not emit an error if `composer.lock` exists and is not up to date.
* **--no-check-publish:** Do not emit an error if `composer.json` is unsuitable for publishing as a package on Packagist but is otherwise valid.
* **--with-dependencies:** Also validate the composer.json of all installed dependencies.
* **--strict:** Return a non-zero exit code for warnings as well as errors.

## status

If you often need to modify the code of your dependencies and they are
installed from source, the `status` command allows you to check if you have
local changes in any of them.

```sh
php composer.phar status
```

With the `--verbose` option you get some more information about what was
changed:

```sh
php composer.phar status -v

You have changes in the following dependencies:
vendor/seld/jsonlint:
    M README.mdown
```

## self-update (selfupdate)

To update Composer itself to the latest version, just run the `self-update`
command. It will replace your `composer.phar` with the latest version.

```sh
php composer.phar self-update
```

If you would like to instead update to a specific release simply specify it:

```sh
php composer.phar self-update 1.0.0-alpha7
```

If you have installed Composer for your entire system (see [global installation](00-intro.md#globally)),
you may have to run the command with `root` privileges

```sh
sudo -H composer self-update
```

### Options

* **--rollback (-r):** Rollback to the last version you had installed.
* **--clean-backups:** Delete old backups during an update. This makes the
  current version of Composer the only backup available after the update.
* **--no-progress:** Do not output download progress.
* **--update-keys:** Prompt user for a key update.
* **--stable:** Force an update to the stable channel.
* **--preview:** Force an update to the preview channel.
* **--snapshot:** Force an update to the snapshot channel.

## config

The `config` command allows you to edit composer config settings and repositories
in either the local `composer.json` file or the global `config.json` file.

Additionally it lets you edit most properties in the local `composer.json`.

```sh
php composer.phar config --list
```

### Usage

`config [options] [setting-key] [setting-value1] ... [setting-valueN]`

`setting-key` is a configuration option name and `setting-value1` is a
configuration value.  For settings that can take an array of values (like
`github-protocols`), more than one setting-value arguments are allowed.

You can also edit the values of the following properties:

`description`, `homepage`, `keywords`, `license`, `minimum-stability`,
`name`, `prefer-stable`, `type` and `version`.

See the [Config](06-config.md) chapter for valid configuration options.

### Options

* **--global (-g):** Operate on the global config file located at
  `$COMPOSER_HOME/config.json` by default.  Without this option, this command
  affects the local composer.json file or a file specified by `--file`.
* **--editor (-e):** Open the local composer.json file using in a text editor as
  defined by the `EDITOR` env variable.  With the `--global` option, this opens
  the global config file.
* **--auth (-a):** Affect auth config file (only used for --editor).
* **--unset:** Remove the configuration element named by `setting-key`.
* **--list (-l):** Show the list of current config variables.  With the `--global`
  option this lists the global configuration only.
* **--file="..." (-f):** Operate on a specific file instead of composer.json. Note
  that this cannot be used in conjunction with the `--global` option.
* **--absolute:** Returns absolute paths when fetching *-dir config values
  instead of relative.

### Modifying Repositories

In addition to modifying the config section, the `config` command also supports making
changes to the repositories section by using it the following way:

```sh
php composer.phar config repositories.foo vcs https://github.com/foo/bar
```

If your repository requires more configuration options, you can instead pass its JSON representation :

```sh
php composer.phar config repositories.foo '{"type": "vcs", "url": "http://svn.example.org/my-project/", "trunk-path": "master"}'
```

### Modifying Extra Values

In addition to modifying the config section, the `config` command also supports making
changes to the extra section by using it the following way:

```sh
php composer.phar config extra.foo.bar value
```

The dots indicate array nesting, a max depth of 3 levels is allowed though. The above
would set `"extra": { "foo": { "bar": "value" } }`.

## create-project

You can use Composer to create new projects from an existing package. This is
the equivalent of doing a git clone/svn checkout followed by a "composer install"
of the vendors.

There are several applications for this:

1. You can deploy application packages.
2. You can check out any package and start developing on patches for example.
3. Projects with multiple developers can use this feature to bootstrap the
   initial application for development.

To create a new project using Composer you can use the "create-project" command.
Pass it a package name, and the directory to create the project in. You can also
provide a version as third argument, otherwise the latest version is used.

If the directory does not currently exist, it will be created during installation.

```sh
php composer.phar create-project doctrine/orm path 2.2.*
```

It is also possible to run the command without params in a directory with an
existing `composer.json` file to bootstrap a project.

By default the command checks for the packages on packagist.org.

### Options

* **--stability (-s):** Minimum stability of package. Defaults to `stable`.
* **--prefer-source:** Install packages from `source` when available.
* **--prefer-dist:** Install packages from `dist` when available.
* **--repository:** Provide a custom repository to search for the package,
  which will be used instead of packagist. Can be either an HTTP URL pointing
  to a `composer` repository, a path to a local `packages.json` file, or a
  JSON string which similar to what the [repositories](04-schema.md#repositories)
  key accepts.
* **--dev:** Install packages listed in `require-dev`.
* **--no-dev:** Disables installation of require-dev packages.
* **--no-scripts:** Disables the execution of the scripts defined in the root
  package.
* **--no-progress:** Removes the progress display that can mess with some
  terminals or scripts which don't handle backspace characters.
* **--keep-vcs:** Skip the deletion of the VCS metadata for the created
  project. This is mostly useful if you run the command in non-interactive
  mode.
* **--no-install:** Disables installation of the vendors.
* **--ignore-platform-reqs:** ignore `php`, `hhvm`, `lib-*` and `ext-*`
  requirements and force the installation even if the local machine does not
  fulfill these.

## dump-autoload (dumpautoload)

If you need to update the autoloader because of new classes in a classmap
package for example, you can use "dump-autoload" to do that without having to
go through an install or update.

Additionally, it can dump an optimized autoloader that converts PSR-0/4 packages
into classmap ones for performance reasons. In large applications with many
classes, the autoloader can take up a substantial portion of every request's
time. Using classmaps for everything is less convenient in development, but
using this option you can still use PSR-0/4 for convenience and classmaps for
performance.

### Options
* **--no-scripts:** Skips the execution of all scripts defined in composer.json file.
* **--optimize (-o):** Convert PSR-0/4 autoloading to classmap to get a faster
  autoloader. This is recommended especially for production, but can take
  a bit of time to run so it is currently not done by default.
* **--classmap-authoritative (-a):** Autoload classes from the classmap only.
  Implicitly enables `--optimize`.
* **--apcu:** Use APCu to cache found/not-found classes.
* **--no-dev:** Disables autoload-dev rules.

## clear-cache (clearcache)

Deletes all content from Composer's cache directories.

## licenses

Lists the name, version and license of every package installed. Use
`--format=json` to get machine readable output.

### Options

* **--format:** Format of the output: text or json (default: "text")
* **--no-dev:** Remove dev dependencies from the output

## run-script

### Options

* **--timeout:** Set the script timeout in seconds, or 0 for no timeout.
* **--dev:** Sets the dev mode.
* **--no-dev:** Disable dev mode.
* **--list (-l):** List user defined scripts.

To run [scripts](articles/scripts.md) manually you can use this command,
just give it the script name and optionally any required arguments.

## exec

Executes a vendored binary/script. You can execute any command and this will
ensure that the Composer bin-dir is pushed on your PATH before the command
runs.

### Options

* **--list (-l):** List the available composer binaries.

## diagnose

If you think you found a bug, or something is behaving strangely, you might
want to run the `diagnose` command to perform automated checks for many common
problems.

```sh
php composer.phar diagnose
```

## archive

This command is used to generate a zip/tar archive for a given package in a
given version. It can also be used to archive your entire project without
excluded/ignored files.

```sh
php composer.phar archive vendor/package 2.0.21 --format=zip
```

### Options

* **--format (-f):** Format of the resulting archive: tar or zip (default:
  "tar")
* **--dir:** Write the archive to this directory (default: ".")
* **--file:** Write the archive with the given file name.

## help

To get more information about a certain command, just use `help`.

```sh
php composer.phar help install
```

## Command-line completion

Command-line completion can be enabled by following instructions
[on this page](https://github.com/bamarni/symfony-console-autocomplete).

## Environment variables

You can set a number of environment variables that override certain settings.
Whenever possible it is recommended to specify these settings in the `config`
section of `composer.json` instead. It is worth noting that the env vars will
always take precedence over the values specified in `composer.json`.

### COMPOSER

By setting the `COMPOSER` env variable it is possible to set the filename of
`composer.json` to something else.

For example:

```sh
COMPOSER=composer-other.json php composer.phar install
```

The generated lock file will use the same name: `composer-other.lock` in this example.

### COMPOSER_ROOT_VERSION

By setting this var you can specify the version of the root package, if it can
not be guessed from VCS info and is not present in `composer.json`.

### COMPOSER_VENDOR_DIR

By setting this var you can make Composer install the dependencies into a
directory other than `vendor`.

### COMPOSER_BIN_DIR

By setting this option you can change the `bin` ([Vendor Binaries](articles/vendor-binaries.md))
directory to something other than `vendor/bin`.

### http_proxy or HTTP_PROXY

If you are using Composer from behind an HTTP proxy, you can use the standard
`http_proxy` or `HTTP_PROXY` env vars. Simply set it to the URL of your proxy.
Many operating systems already set this variable for you.

Using `http_proxy` (lowercased) or even defining both might be preferable since
some tools like git or curl will only use the lower-cased `http_proxy` version.
Alternatively you can also define the git proxy using
`git config --global http.proxy <proxy url>`.

If you are using Composer in a non-CLI context (i.e. integration into a CMS or
similar use case), and need to support proxies, please provide the `CGI_HTTP_PROXY`
environment variable instead. See [httpoxy.org](https://httpoxy.org/) for further
details.

### no_proxy

If you are behind a proxy and would like to disable it for certain domains, you
can use the `no_proxy` env var. Simply set it to a comma separated list of
domains the proxy should *not* be used for.

The env var accepts domains, IP addresses, and IP address blocks in CIDR
notation. You can restrict the filter to a particular port (e.g. `:80`). You
can also set it to `*` to ignore the proxy for all HTTP requests.

### HTTP_PROXY_REQUEST_FULLURI

If you use a proxy but it does not support the request_fulluri flag, then you
should set this env var to `false` or `0` to prevent Composer from setting the
request_fulluri option.

### HTTPS_PROXY_REQUEST_FULLURI

If you use a proxy but it does not support the request_fulluri flag for HTTPS
requests, then you should set this env var to `false` or `0` to prevent Composer
from setting the request_fulluri option.

### COMPOSER_HOME

The `COMPOSER_HOME` var allows you to change the Composer home directory. This
is a hidden, global (per-user on the machine) directory that is shared between
all projects.

By default it points to `C:\Users\<user>\AppData\Roaming\Composer` on Windows
and `/Users/<user>/.composer` on OSX. On *nix systems that follow the [XDG Base
Directory Specifications](http://standards.freedesktop.org/basedir-spec/basedir-spec-latest.html),
it points to `$XDG_CONFIG_HOME/composer`. On other *nix systems, it points to
`/home/<user>/.composer`.

#### COMPOSER_HOME/config.json

You may put a `config.json` file into the location which `COMPOSER_HOME` points
to. Composer will merge this configuration with your project's `composer.json`
when you run the `install` and `update` commands.

This file allows you to set [repositories](05-repositories.md) and
[configuration](06-config.md) for the user's projects.

In case global configuration matches _local_ configuration, the _local_
configuration in the project's `composer.json` always wins.

### COMPOSER_CACHE_DIR

The `COMPOSER_CACHE_DIR` var allows you to change the Composer cache directory,
which is also configurable via the [`cache-dir`](06-config.md#cache-dir) option.

By default it points to $COMPOSER_HOME/cache on \*nix and OSX, and
`C:\Users\<user>\AppData\Local\Composer` (or `%LOCALAPPDATA%/Composer`) on Windows.

### COMPOSER_PROCESS_TIMEOUT

This env var controls the time Composer waits for commands (such as git
commands) to finish executing. The default value is 300 seconds (5 minutes).

### COMPOSER_CAFILE

By setting this environmental value, you can set a path to a certificate bundle
file to be used during SSL/TLS peer verification.

### COMPOSER_AUTH

The `COMPOSER_AUTH` var allows you to set up authentication as an environment variable.
The contents of the variable should be a JSON formatted object containing http-basic,
github-oauth, bitbucket-oauth, ... objects as needed, and following the
[spec from the config](06-config.md#gitlab-oauth).

### COMPOSER_DISCARD_CHANGES

This env var controls the [`discard-changes`](06-config.md#discard-changes) config option.

### COMPOSER_NO_INTERACTION

If set to 1, this env var will make Composer behave as if you passed the
`--no-interaction` flag to every command. This can be set on build boxes/CI.

### COMPOSER_ALLOW_SUPERUSER

If set to 1, this env disables the warning about running commands as root/super user.
It also disables automatic clearing of sudo sessions, so you should really only set this
if you use Composer as super user at all times like in docker containers.

### COMPOSER_MIRROR_PATH_REPOS

If set to 1, this env changes the default path repository strategy to `mirror` instead
of `symlink`. As it is the default strategy being set it can still be overwritten by
repository options.

### COMPOSER_HTACCESS_PROTECT

Defaults to `1`. If set to `0`, Composer will not create `.htaccess` files in the
composer home, cache, and data directories.

&larr; [Libraries](02-libraries.md)  |  [Schema](04-schema.md) &rarr;