Crystal

Similar to ruby Dir.

Work with pattern scan, but currently ** not supported ⚠recursive issue

Dir["/app/**"].each {|filename|
  puts filename
}

Ruby / SO

Dir["**/*"].each do |filename|
  puts filename
end

see also

• How to list directory contents including dotfiles but not . and ..?
• Paths in Ruby - for path manipulation, eg: File.expand_path( File.join( File.dirname(__FILE__), '../other' )) or File.expand_path('../other', __FILE__)

C++

#include <filesystem>
namespace fs = std::filesystem;
 
int main() {
    for(auto& p: fs::directory_iterator("/app"))
        std::cout << p.path() << '\n';
}

for g++ version < 9.0 link with -lstdc++fs see undefined reference when using experimental/filesystem