If you're trying to install composer with curl -s https://getcomposer.org/installer | php command and having this error
detect_unicode = Off
A php.ini file does not exist. You will have to create one.
You can avoid this problem by passing -d detect_unicode=Off as an argument for php like this
curl -s https://getcomposer.org/installer | php -d detect_unicode=Offhttp://www.andrew-kirkpatrick.com/2012/10/install-composer-for-php-on-zend-server-mac-os-x/