how to download composer on terminal code example

Example 1: update composer mac

#Ubuntu-Download Composer and create a Phar (PHP Archive) file
$ curl -s https://getcomposer.org/installer | php

#Move it to bin directory
$ sudo mv composer.phar /usr/local/bin/composer

Example 2: install composer

php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');"
php -r "if (hash_file('sha384', 'composer-setup.php') === '795f976fe0ebd8b75f26a6dd68f78fd3453ce79f32ecb33e7fd087d39bfeb978342fb73ac986cd4f54edd0dc902601dc') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;"
php composer-setup.php
php -r "unlink('composer-setup.php');"