如何从不同的目录require_once？ [英] How to require_once from different directories?

问题描述

我正在尝试从不同文件夹的php文件中要求我的库文件，但是尝试从子文件夹访问它时会产生错误。例如我有一个目录：

  + home 
  -  file1.php 
 
 ++子文件夹
  -  file2.php 
 
 ++库
  -  code_generator.php 
  -  database_library.php 
  / pre> 
 
 
  code_generator.php 也取决于其他库：
 （第25行）require_once（realpath（./ libraries / database_library.php））; 
 //这可以从file1.php调用，但不是来自file2.php 
  
我尝试从./subfolder/  file2.php 调用code_generator，如：
  chmod（ ../libraries/codegenerator.php，0777）; //对于这个问题的结尾的错误
 require_once（../ libraries / code_generator.php）; 
  
当我运行file2.php时，会产生2个错误：
  **警告**：require_once（C：\xampp\htdocs\home\subfolder）：无法打开流：C：中的权限被拒绝在线25上的\\ xampp\htdocs\home\libraries\code_generator.php 
 
 **致命错误**：require_once（）：打开必需的''（include_path ='; C ：\xampp\php\PEAR'）在C：\xampp\htdocs\home\libraries\code_generator.php第25行
  
 *第25行是 require_once（realpath（./ libraries / database_library.php））;  
解决方案
 
该文件不存在> 
 
 
错误消息如下：
 
 
 警告：require_once（C：\xampp\htdocs\home\\ \\ subfolder）：无法打开流：
 
 
 And：
 
 
  
 
无法打开所需的''
 
 
错误消息永远不会（好吧，几乎从未），所以你 调用：
  require_once（''）; 
  
 
 
 
 Realpath对于缺少的文件返回false 
 
 
 
如果您将路径传递给不存在的文件，Realpath将返回false：
  $ return = realpath（'this /doesnt/exist.foo'）; // $ return is false 
  
因此，传递给realpath的参数不指代文件，这是路径不起作用的原因。
 
 
 
不要超过使用realpath 
 
 
 
如果您删除使用realpath，你会发现错误信息很明显。猜测你试图包含 C：\xampp\htdocs\home\subfolder\libraries\database_library.php   - 因为有一个缺失 
 
 
第25行是 require_once realpath（./ libraries / database_library.php））;  
 
 
如果你只是定义一个根路径：
  define（'ROOT'，'C：\xampp\htdocs\home\\' ）; 
  
然后你可以绝对地使用这个常数，这些问题不会发生：
  require_once（ROOT。libraries / database_library.php）; 
  
如果您的路径错误，错误消息将显示出问题所在。 
 
I am trying to require my "library" files from php files in different folders, but it gives errors when trying to access them from a subfolder. For example I have such a directory:
+ home    
- file1.php

 ++ subfolder
  - file2.php

 ++ libraries
  - code_generator.php
  - database_library.php
code_generator.php also depends on the other library:
(LINE 25) require_once(realpath("./libraries/database_library.php"));
//this works fine when called from file1.php, but not from file2.php
I try to call code_generator from ./subfolder/file2.php like:
chmod("../libraries/codegenerator.php", 0777);  // for the error at the end of this question
require_once("../libraries/code_generator.php");
When I run file2.php, it yields 2 errors:
**Warning**: require_once(C:\xampp\htdocs\home\subfolder): failed to open stream: Permission denied in C:\xampp\htdocs\home\libraries\code_generator.php on line 25

**Fatal error**: require_once(): Failed opening required '' (include_path='.;C:\xampp\php\PEAR') in C:\xampp\htdocs\home\libraries\code_generator.php on line 25
*line 25 is require_once(realpath("./libraries/database_library.php"));
解决方案
The file does not exist.

The error message reads:

  
Warning: require_once(C:\xampp\htdocs\home\subfolder): failed to open stream:
And:

  
Failed opening required ''
Error messages never lie (well, almost never), therefore you are calling:
require_once('');


Realpath returns false for missing files

Realpath will return false if you pass it a path to a file that doesn't exist:
$return = realpath('this/doesnt/exist.foo'); // $return is false
Therefore, the argument passed to realpath doesn't refer to a file, which is the reason the path doesn't work.

Don't over use realpath

If you remove the use of realpath, you'll find that the error message is probably obvious. At a guess you're trying to include C:\xampp\htdocs\home\subfolder\libraries\database_library.php - because there is a missing . in this:

  
line 25 is require_once(realpath("./libraries/database_library.php"));
If instead you just define a root path:
define('ROOT', 'C:\xampp\htdocs\home\\');
Then you can use this constant with absolute confidence that these sort of problems wont occur:
require_once(ROOT . "libraries/database_library.php");
And if you do get the path wrong, the error message will make it obvious what the problem is.

                        
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