nginx - Linux source code compilation problem. What is the significance of the design of --with-module and --without-module?

Question

When compiling and installing nginx source code, I saw ./configure --help, which I didn’t quite understand

  --with-http_ssl_module             enable ngx_http_ssl_module
  --with-http_v2_module              enable ngx_http_v2_module
  --with-http_realip_module          enable ngx_http_realip_module
  --with-http_addition_module        enable ngx_http_addition_module
  --with-http_xslt_module            enable ngx_http_xslt_module
  --with-http_xslt_module=dynamic    enable dynamic ngx_http_xslt_module
  --with-http_image_filter_module    enable ngx_http_image_filter_module
  --with-http_image_filter_module=dynamic

  --with-select_module               enable select module
  --without-select_module            disable select module
  --with-poll_module                 enable poll module
  --without-poll_module              disable poll module

Do the above http_ssl module and http_v2 module need to be specified in ./configure before adding and using this function?
If all --with needs to be specified after ./configure to compile before it can be used, then what's the point of --without?

For example, if the above select_module needs to be specified by ./configure --with-select_module before it can be compiled and used, what is the significance of the --without-select_module compilation configuration option?

Answer 1

Some modules are compiled by default, and some are not compiled. For those that are compiled by default, if you don’t want to use them, you can use without. For those that are not compiled by default, if you want to use them, use with.

This is how it is described in the official documentationselect_module

--with-select_module

--without-select_module
— enables or disables building a module that allows the server to work with the select() method. This module is built automatically if the platform does not appear to support more appropriate methods such as kqueue, epoll, or /dev/poll.

For those that have both with and without, such as the

module, this module will select_moduledetermine whether the module will be automatically compiled into nginx by default based on the system's support. So there are two options to manually control this behavior. Other modules, if only

is provided, it means they are compiled by default