如何测试 cmake 中是否存在与 glob 匹配的文件名？

Question

我想创建一个条件，仅当具有指定 glob 的文件名存在时，该条件才为 true。像这样（它不是工作cmake代码，只是为了表达我的意图）：

if(EXISTS "${LIBRARY_PATH}/lib*.a")
  ...
elseif(EXISTS "${LIBRARY_PATH}/lib/*.dll")
  ...

Answer 1

file( GLOB cmake_varibale ${LIBRARY_PATH}/lib*.a )

将把所有匹配文件的列表放入 中cmake_variable，然后您可以测试它是否为空。

从cmake --help-command file：

     ...
     file(GLOB variable [RELATIVE path] [globbing expressions]...)
     file(GLOB_RECURSE variable [RELATIVE path] 
          [FOLLOW_SYMLINKS] [globbing expressions]...)
     ...

   ...

   GLOB will generate a list of all files that match the globbing
   expressions and store it into the variable.  Globbing expressions are
   similar to regular expressions, but much simpler.  If RELATIVE flag is
   specified for an expression, the results will be returned as a
   relative path to the given path.  (We do not recommend using GLOB to
   collect a list of source files from your source tree.  If no
   CMakeLists.txt file changes when a source is added or removed then the
   generated build system cannot know when to ask CMake to regenerate.)

   Examples of globbing expressions include:

      *.cxx      - match all files with extension cxx
      *.vt?      - match all files with extension vta,...,vtz
      f[3-5].txt - match files f3.txt, f4.txt, f5.txt

   GLOB_RECURSE will generate a list similar to the regular GLOB, except
   it will traverse all the subdirectories of the matched directory and
   match the files.  Subdirectories that are symlinks are only traversed
   if FOLLOW_SYMLINKS is given or cmake policy CMP0009 is not set to NEW.
   See cmake --help-policy CMP0009 for more information.

   Examples of recursive globbing include:

      /dir/*.py  - match all python files in /dir and subdirectories

   ...