Erlang: "include_lib"和 "include"有什么区别？

Question

"include_lib"和 "include"和有什么不一样？

例如。
-include_lib("eunit/include/eunit.hrl")

Answer 1

文档描述的方式 the difference between include and include_lib是:

include_lib is similar to include, but should not point out an absolute file. Instead, the first path component (possibly after variable substitution) is assumed to be the name of an application.

Example:

-include_lib("kernel/include/file.hrl").

The code server uses code:lib_dir(kernel) to find the directory of the current (latest) version of Kernel, and then the subdirectory include is searched for the file file.hrl.

因此，在您的示例中，您无需指出包含的 eunit 版本，而是包含库路径中存在的 eunit:s 的最新 eunit.hrl。