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要搞懂 readdir()函数的用法和Linux目录结构,
Home Backend Development PHP Tutorial 请问一下php函数中输出 readdir()的中 “.”,“..”的含义??

请问一下php函数中输出 readdir()的中 “.”,“..”的含义??

Jun 06, 2016 pm 08:26 PM
php

  1. 如果while(readdir($dir) !==false) { var_dump()) } 会输出 “ .” 和“..”已经其他文件名,其中“.”,“..”代表啥意思呀???
    不要告诉我表示当前目录,及上级目录,我不理解为什么会这样输出,他们是相对谁的目录而言的呢??
    -

  2. 还有就是不管我的目录层级多少级,都只输出“.”,“..”为什么不输出的、更多的目录??就自己输出我的根目录文件名了呢?例如 我的
    $dir = "D:/www/www.test.whk/1111/2222/3333/4444/5555/"; 但是我输出readdir时是
    string(1) "."
    string(2) ".."
    string(8) "test.txt"
    bool(false)
    bool(false)
    bool(false) , 为啥就输出两级目录呢,明明应该是7级目录的呀??不懂!求解!!

回复内容:

  1. 如果while(readdir($dir) !==false) { var_dump()) } 会输出 “ .” 和“..”已经其他文件名,其中“.”,“..”代表啥意思呀???
    不要告诉我表示当前目录,及上级目录,我不理解为什么会这样输出,他们是相对谁的目录而言的呢??
    -

  2. 还有就是不管我的目录层级多少级,都只输出“.”,“..”为什么不输出的、更多的目录??就自己输出我的根目录文件名了呢?例如 我的
    $dir = "D:/www/www.test.whk/1111/2222/3333/4444/5555/"; 但是我输出readdir时是
    string(1) "."
    string(2) ".."
    string(8) "test.txt"
    bool(false)
    bool(false)
    bool(false) , 为啥就输出两级目录呢,明明应该是7级目录的呀??不懂!求解!!

结合楼上们的提议,自己总算搞明白了,

要搞懂 readdir()函数的用法和Linux目录结构,

  • readdir() php manual上是这样写的,返回目录中下一个文件的文件名,切文件名以在文件系统中的排序返回,


  • 看鸟哥的私房菜,上文档目录这部分是这样介绍的,每个目录底下都会存在的两个目录,分别是‘.’,‘..’

综上所述,就不能理解了,

常识问题,.当前目录,..上级目录

新增:不好意思,我只看到了第一句问号。。。请查阅文档:http://php.net/manual/zh/function.readdir.php

楼主要知道,文件夹也是文件的一种特别存在形式,你读取当前目录,意思是读取当前目录下的文件。当前目录下只有当前目录和上级目录的句柄,当然还有下层目录的句柄和当前目录下的文件。所以你读到这些,而不会有其他的路径信息。

这里楼主可能多理解下linux的文件结构,会更好的理解这个问题

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