PHP implementation gets the current file parent directory method Summary

This article summarizes the use of PHP to get the current file directory of the parent directory of 2 ways, and attached to the PHP get path and directory related functions, the need for small partners can refer to the following

method One: first obtain the length of the folder in which the current file is located, and then use substr to intercept the length:

The code is as follows:

$dirName = str_replace ("\ \", "/", DirName (__file__)), $dirNameLength = strlen ($dirName); $currentDirNameLength = $ Dirnamelength-strrpos ($dirName, "/"); Get the length of the folder where the current file is located! $parentDirName = substr ($dirName, 0,-$currentDirNameLength); If the 3rd parameter is a negative number, then the "absolute value of this parameter" character is truncated from the back.

method Two: the current file in the same folder as a file (folder is actually a special file, everything is a file!!) ), dirname can be nested directly with dirname:

$parentDirName = DirName (dirname (__file__));

From the above can be seen: the deep understanding of things, can greatly improve the code quality!

Attached: PHP Get path or directory implementation

PHP gets directories and methods through magic variables, through super global variables, through related functions and so on:

<?php/** * php get path or directory implementation *///Magic variable, get the absolute path of the current file echo "__file__: ========>". _ _file__; Echo ' <br/> '; Magic variable, gets the directory of the current script echo "__dir__: ========>". __dir__;echo ' <br/> '; DirName returns the directory portion of the path, dirname (__file__) equals __dir__echo "DirName (__file__): ========>". dirname (__file__); Echo ' < Br/> '; The results of $_server[' php_self ' and $_server[' script_name '] are generally the same, they all get the file name of the current script//Only when PHP is running in CGI mode, But now it's almost impossible to find a CGI run of PHP Echo ' $_server[' Php_self "]: ========> '. $_server[' php_self '];echo ' <br/> '; Echo ' $_server[' Script_name "]: ========> '. $_server[' script_name '];echo ' <br/> '; The absolute path of the current execution script. Remember that running PHP in the CLI mode is not getting the echo ' $_server[' Script_filename "]: ========> '. $_server[' script_filename '];echo ' <br/ > '; The document root directory where the script is currently running. Defined in the server configuration file. Echo ' $_server[' Document_root "]: ========> '. $_server[' document_root '];echo ' <br> '; GETCWD () returns the current working directory echo "GETCWD (): ========>". GETCWD (); Echo ' <br> '; 

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