CodeIgniter Source Code Analysis (ii) entry file index.php

1<?PHP2 3 /*Setting the Environment*/4 Define(' Environment ', ' development ');5 6 if(defined(' Environment '))7 {8     Switch(Environment)9     {Ten          Case' Development ': One             error_reporting(E_all); A          Break; -      -          Case' Testing ': the          Case' Production ': -             error_reporting(0); -          Break; -  +         default: -             Exit(' The application environment is not set correctly. '); +     } A } at  - /*System Folder name*/ - $system _path= ' System '; -  - /*Apply folder name*/ - $application _folder= ' Application '; in  - //change the current directory to the specified directory to if(defined(' STDIN ')) + { -     chdir(dirname(__file__)); the } *  $ if(Realpath($system _path) !==FALSE)//return Absolute PathPanax Notoginseng { -     $system _path=Realpath($system _path).‘ /‘; the } +  A //system Path the $system _path=RTrim($system _path, ‘/‘).‘ /‘; +  -  $ if( !Is_dir($system _path)) $ { -     Exit("System file path setting error"); - } the     //the name of the current file -     Define(' Self ',PathInfo(__file__,pathinfo_basename));Wuyi  the     //file name extension -     Define(' EXT ', '. php '); Wu  -     //Path to the system folder About     Define(' BasePath ',Str_replace("\\", "/",$system _path)); $  -     //Path to the front controller (this file) -     Define(' Fcpath ',Str_replace(Self, ",__file__)); -  A     //Name of the "System Folder" +     Define(' Sysdir ',Trim(STRRCHR(Trim(BasePath, '/'), '/'), '/')); the  -     //the path to the "Application" folder $     if(Is_dir($application _folder)) the     { the         Define(' APPPATH ',$application _folder.‘ /‘); the     } the     Else -     { in         if( !Is_dir(BasePath.$application _folder.‘ /‘)) the         { the             Exit("App Folder settings Error"); About         } the  the         Define(' APPPATH ', basepath.$application _folder.‘ /‘); the     } +  - /* the  * --------------------------------------------------------------------Bayi * LOAD the BOOTSTRAP FILE the  * -------------------------------------------------------------------- the  * - * and Away we go ... -  * the  */ the require_onceBasePath. ' Core/codeigniter.php '; the  the /*End of File index.php*/ - /*Location :./index.php*/

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This file is mainly about setting up the project run environment

Set System system Directory

Set some constants: Self, EXT, basepath ...

CodeIgniter Source Code Analysis (ii) entry file index.php