This directive is from the description of the official docker php image:
RUN apt-get update && apt-get install -y \
libfreetype6-dev \
libjpeg62-turbo-dev \
libmcrypt-dev \
libpng12-dev \
&& docker-php-ext-install -j$(nproc) iconv mcrypt \
&& docker-php-ext-configure gd --with-freetype-dir=/usr/include/ --with-jpeg-dir=/usr/include/ \
&& docker-php-ext-install -j$(nproc) gd
I have two questions:
- What are the packages with the
-dev
suffix for? How do I know I need them and which ones in particular? - What is
-j$(nproc)
?