ubuntu@ip-10-139-41-170:~/php-5.5.15$ php -i | strace php 2>&1 | grep '/etc/php'
Configure Command =>  './configure'  '--with-apxs2=/usr/bin/apxs' '--with-bz2=/usr/include' '--enable-calendar' '--with-curl=/usr/include' '--enable-exif' '--enable-ftp' '--with-gd' '--with-freetype-dir=/usr/include' '--with-jpeg-dir=/usr/include' '--with-png-dir=/usr/include' '--with-gettext=/usr/include' '--enable-mbstring' '--with-mcrypt=/usr/include' '--with-mysql=mysqlnd' '--with-mysqli=mysqlnd' '--with-pdo-mysql=mysqlnd' '--enable-shmop' '--enable-libxml' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-sysvmsg' '--with-xsl' '--with-zlib-dir=/usr/include' '--enable-bcmath' '--enable-gd-native-ttf' '--with-config-file-path=/etc/php' '--with-openssl'
Configuration File (php.ini) Path => /etc/php