ysqdeMacBook-Pro:~ ysq$ curl -sS https://getcomposer.org/installer | php
All settings correct for using Composer
Downloading...
Composer (version 1.8.5) successfully installed to: /Users/ysq/composer.phar
Use it: php composer.phar
ysqdeMacBook-Pro:~ ysq$ php composer.phar --version
Composer version 1.8.5 2019-04-09 17:46:47
ysqdeMacBook-Pro:~ ysq$ mv composer.phar /usr/local/bin/composer