如何加载目录中的所有文件？ [英] How to load all files from a directory?

问题描述

像标题所说的那样;我如何加载目录中的每个文件？我对c ++和lua都很感兴趣。

编辑：
对于windows，我很乐意看到一些真正的工作代码，尤其是对于lua。我可以使用boost :: filesystem for c ++。

解决方案

对于Lua，您希望模块 Lua文件系统。正如Nick所观察到的那样，访问文件系统本身（而不是单个文件）不在C和C ++标准的范围之内。由于Lua本身是（用C语言实现require（）的动态加载器的例外），所以核心语言缺少很多文件系统特性。

但是，由于（几乎）具有文件系统的任何平台也支持DLL或共享库，所以很容易扩展Lua核心。 Lua文件系统是一个可移植的库，它增加了对目录迭代，文件属性发现等的支持。

使用lfs，在Lua中模拟DIR的一些功能是基本上就像这样简单：

 需要lfs
 dot = arg [1]或者。 
在lfs.dir（dot）中的名称做
本地fqn =点../..名称
本地attr = lfs.attributes（fqn）
 print（name ，attr.mode，os.date（％Y-％m-％d％H：％M，attr.modification），attr.size）
 end 
  
  
 
 
产生如下输出： 
 
 
  E ：...> t-lfs.lua 
。目录2009-04-02 13:23 0 
 ..目录2009-04-02 13:18 0 
 foo.txt文件2009-02-23 01:56 0 
 t-lfs .lua file 2009-04-02 13:18 241 
 
 E：...> 
  
如果您的Lua副本来自 Lua for Windows ，那么你已经安装了lfs，上面的例子就可以使用了。顺便说一句，Lua解决方案也可能是一个明智的C或C ++解决方案。 Lua核心并不大，提供了一种动态的，垃圾收集的语言，并且可以很容易地与C进行交互，既可以作为托管应用程序，也可以作为扩展模块。要从C应用程序使用lfs，你需要链接到Lua DLL，初始化一个Lua状态，并通过<$ c来获得执行 requirelfs的状态$ c> luaL_dostring（）或者使用C API从全局表中检索 require（）函数，将字符串lfs，然后用类似于 lua_pcall（L，1,1,0）的方式调用Lua函数， code> lfs 在Lua堆栈顶部的表。
 
 
 
如果您已经有需要，这种方法可能是最有意义的对于嵌入式脚本语言，Lua符合您的要求。 
Like the title says; how do I load every file in a directory? I'm interested in both c++ and lua.

Edit:
For windows I'd be glad for some real working code and especially for lua. I can do with boost::filesystem for c++.
解决方案
For Lua, you want the module Lua Filesystem. 

As observed by Nick, accessing the file system itself (as opposed to individual files) is outside the scope of the C and C++ standards. Since Lua itself is (with the exception of the dynamic loader used to implement require() for C modules) written in standard C, the core language lacks many file system features.

However, it is easy to extend the Lua core since (nearly) any platform that has a file system also supports DLLs or shared libraries. Lua File system is a portable library that adds support for directory iteration, file attribute discovery, and the like.

With lfs, emulating some of the capability of DIR in Lua is essentially as simple as:
require "lfs"
dot = arg[1] or "."
for name in lfs.dir(dot) do
    local fqn = dot.."/"..name
    local attr = lfs.attributes(fqn)
    print(name, attr.mode, os.date("%Y-%m-%d %H:%M",attr.modification), attr.size)
end
Which produces output that looks like:
E:...>t-lfs.lua
.       directory       2009-04-02 13:23        0
..      directory       2009-04-02 13:18        0
foo.txt file    2009-02-23 01:56        0
t-lfs.lua       file    2009-04-02 13:18        241

E:...>
If your copy of Lua came from Lua for Windows, then you already have lfs installed, and the above sample will work out of the box. 

Edit: Incidentally, the Lua solution might also be a sensible C or C++ solution. The Lua core is not at all large, provides a dynamic, garbage-collected language, and is easy to interact with from C either as a hosting application or as an extension module. To use lfs from a C application, you would link with the Lua DLL, initialize a Lua state, and get the state to execute the require"lfs" either via luaL_dostring() or by using the C API to retrieve the require() function from the global table, push the string "lfs", and call the Lua function with something like lua_pcall(L,1,1,0), which leaves the lfs table on the top of the Lua stack.

This approach probably makes the most sense if you already had a need for an embedded scripting language, and Lua meets your requirements.

                        
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