Composer have 14 Environment Variables

  1. COMPOSER
  2. COMPOSER_ROOT_VERSION
  3. COMPOSER_VENDOR_DIR
  4. COMPOSER_BIN_DIR
  5. http_proxy or HTTP_PROXY
  6. no_proxy
  7. HTTP_PROXY_REQUEST_FULLURI
  8. HTTPS_PROXY_REQUEST_FULLURI
  9. COMPOSER_HOME
  10. COMPOSER_HOME/config.json
  11. COMPOSER_CACHE_DIR
  12. COMPOSER_PROCESS_TIMEOUT
  13. COMPOSER_DISCARD_CHANGES
  14. COMPOSER_NO_INTERACTION

Composer.json Schema have 24 Fields

  1. name
  2. description
  3. version
  4. type
  5. keywords
  6. homepage
  7. time
  8. license
  9. authors
  10. support
  11. Package links
    1. require
    2. require-dev (root-only)
    3. conflict
    4. replace
    5. provide
  12. suggest
  13. autoload
    1. PSR-4
    2. PSR-0
    3. Classmap
    4. Files
  14. autoload-dev (root-only)
  15. include-path
  16. target-dir
  17. minimum-stability (root-only)
  18. prefer-stable (root-only)
  19. repositories (root-only)
  20. config (root-only)
  21. scripts (root-only)
  22. extra
  23. bin
  24. archive

Composer have 28 Commands and 9 Options

Usage:
[options] command [arguments]

Options:

  1. --help, -h
  2. --quiet, -q
  3. --verbose, -v|vv|vvv
  4. --version, -V
  5. --ansi
  6. --no-ansi
  7. --no-interaction, -n
  8. --profile
  9. --working-dir, -d
Commands:
  1. about
  2. archive
  3. browse
  4. clear-cache
  5. clearcache
  6. config
  7. create-project
  8. depends
  9. diagnose
  10. dump-autoload
  11. dumpautoload
  12. global
  13. help
  14. home
  15. init
  16. install
  17. licenses
  18. list
  19. remove
  20. require
  21. run-script
  22. search
  23. self-update
  24. selfupdate
  25. show
  26. status
  27. update
  28. validate

Composer Install on Mac

via Terminal (local)
curl -s http://getcomposer.org/installer | php
or
php -r "readfile('https://getcomposer.org/installer');" | php

via Terminal (global)

curl -sS https://getcomposer.org/installer | php
sudo mv composer.phar /usr/local/bin/composer

via Homebrew (global)
brew update
brew tap homebrew/dupes
brew tap homebrew/php
brew install composer

run (local)
php composer.phar install

run (global)
composer install