问题
I can't believe PHP doesn't have an easy solution of this simple matter. ASP.NET has a ~ sign that cares of this issue and starts everything from root level. Here's my problem:
localhost/MySite
-->Admin
-- Edit.php
-->Class
-- class.EditInfo.php
-->Texts
-- MyInfo.txt
--ShowInfo.php
Inside class.EditInfo.php I am accessing MyInfo.txt so I defined a relative path "../Texts/MyInfo.txt". Then I created an object of EditInfo in Admin/Edit.php and accessed Texts/MyInfo.txt it worked fine.
But now I have to create an object of EditInfo in ShowInfo.php and access Texts/MyInfo.txt and here's the problem occurs. As I am using a relative path in my class whenever I am creating an objEditInfo and trying to access MyInfo.txt I am getting "File doesn't exist" error.
Now I am looking for something that's equivalent to "~/Texts/MyInfo.txt" of ASP.NET. Is there anything similar to that out there??? Or do I have to set the path with some if/else condition?
UPDATE:
I used $_SERVER['DOCUMENT_ROOT']. I was using a subfolder where my actual website was. So I had to use $_SERVER['DOCUMENT_ROOT']."/mySite" & then adding rest of the address ("/Texts/MyInfo.php") to it.
回答1:
Create a constant with absolute path to the root by using define in ShowInfo.php:
define('ROOTPATH', __DIR__);
Or PHP <= 5.3
define('ROOTPATH', dirname(__FILE__));
Now use it:
if (file_exists(ROOTPATH.'/Texts/MyInfo.txt')) {
// ...
}
Or use the DOCUMENT_ROOT defined in $_SERVER:
if (file_exists($_SERVER['DOCUMENT_ROOT'].'/Texts/MyInfo.txt')) {
// ...
}
回答2:
In PHP there is a global variable containing various details related to the server. It's called $_SERVER. It contains also the root:
$_SERVER['DOCUMENT_ROOT']
The only problem is that the entries in this variable are provided by the web server and there is no guarantee that all web servers offer them.
回答3:
It always best to start any custom PHP project with a bootstrap file where you define the most commonly used paths as constants, based on values extracted from $_SERVER. It should make migrating your projects or parts of your project to another server or to another directory on the server a hell of a lot easier.
This is how I define my root paths :
define("LOCAL_PATH_ROOT", $_SERVER["DOCUMENT_ROOT"]);
define("HTTP_PATH_ROOT", isset($_SERVER["HTTP_HOST"]) ? $_SERVER["HTTP_HOST"] : (isset($_SERVER["SERVER_NAME"]) ? $_SERVER["SERVER_NAME"] : '_UNKNOWN_'));
The path LOCAL_PATH_ROOT is the document root. The path HTTP_PATH_ROOT is the equivalent when accessing the same path via HTTP.
At that point, converting any local path to an HTTP path can be done with the following code :
str_replace(LOCAL_PATH_ROOT, RELATIVE_PATH_ROOT, $my_path)
If you want to ensure compatibility with Windows based servers, you'll need to replace the directory seperator with a URL seperator as well :
str_replace(LOCAL_PATH_ROOT, RELATIVE_PATH_ROOT, str_replace(DIRECTORY_SEPARATOR, '/', $my_path))
Here's the full bootstrap code that I'm using for the PHP PowerTools boilerplate :
defined('LOCAL_PATH_BOOTSTRAP') || define("LOCAL_PATH_BOOTSTRAP", __DIR__);
// -----------------------------------------------------------------------
// DEFINE SEPERATOR ALIASES
// -----------------------------------------------------------------------
define("URL_SEPARATOR", '/');
define("DS", DIRECTORY_SEPARATOR);
define("PS", PATH_SEPARATOR);
define("US", URL_SEPARATOR);
// -----------------------------------------------------------------------
// DEFINE ROOT PATHS
// -----------------------------------------------------------------------
define("RELATIVE_PATH_ROOT", '');
define("LOCAL_PATH_ROOT", $_SERVER["DOCUMENT_ROOT"]);
define("HTTP_PATH_ROOT",
isset($_SERVER["HTTP_HOST"]) ?
$_SERVER["HTTP_HOST"] : (
isset($_SERVER["SERVER_NAME"]) ?
$_SERVER["SERVER_NAME"] : '_UNKNOWN_'));
// -----------------------------------------------------------------------
// DEFINE RELATIVE PATHS
// -----------------------------------------------------------------------
define("RELATIVE_PATH_BASE",
str_replace(LOCAL_PATH_ROOT, RELATIVE_PATH_ROOT, getcwd()));
define("RELATIVE_PATH_APP", dirname(RELATIVE_PATH_BASE));
define("RELATIVE_PATH_LIBRARY", RELATIVE_PATH_APP . DS . 'vendor');
define("RELATIVE_PATH_HELPERS", RELATIVE_PATH_BASE);
define("RELATIVE_PATH_TEMPLATE", RELATIVE_PATH_BASE . DS . 'templates');
define("RELATIVE_PATH_CONFIG", RELATIVE_PATH_BASE . DS . 'config');
define("RELATIVE_PATH_PAGES", RELATIVE_PATH_BASE . DS . 'pages');
define("RELATIVE_PATH_ASSET", RELATIVE_PATH_BASE . DS . 'assets');
define("RELATIVE_PATH_ASSET_IMG", RELATIVE_PATH_ASSET . DS . 'img');
define("RELATIVE_PATH_ASSET_CSS", RELATIVE_PATH_ASSET . DS . 'css');
define("RELATIVE_PATH_ASSET_JS", RELATIVE_PATH_ASSET . DS . 'js');
// -----------------------------------------------------------------------
// DEFINE LOCAL PATHS
// -----------------------------------------------------------------------
define("LOCAL_PATH_BASE", LOCAL_PATH_ROOT . RELATIVE_PATH_BASE);
define("LOCAL_PATH_APP", LOCAL_PATH_ROOT . RELATIVE_PATH_APP);
define("LOCAL_PATH_LIBRARY", LOCAL_PATH_ROOT . RELATIVE_PATH_LIBRARY);
define("LOCAL_PATH_HELPERS", LOCAL_PATH_ROOT . RELATIVE_PATH_HELPERS);
define("LOCAL_PATH_TEMPLATE", LOCAL_PATH_ROOT . RELATIVE_PATH_TEMPLATE);
define("LOCAL_PATH_CONFIG", LOCAL_PATH_ROOT . RELATIVE_PATH_CONFIG);
define("LOCAL_PATH_PAGES", LOCAL_PATH_ROOT . RELATIVE_PATH_PAGES);
define("LOCAL_PATH_ASSET", LOCAL_PATH_ROOT . RELATIVE_PATH_ASSET);
define("LOCAL_PATH_ASSET_IMG", LOCAL_PATH_ROOT . RELATIVE_PATH_ASSET_IMG);
define("LOCAL_PATH_ASSET_CSS", LOCAL_PATH_ROOT . RELATIVE_PATH_ASSET_CSS);
define("LOCAL_PATH_ASSET_JS", LOCAL_PATH_ROOT . RELATIVE_PATH_ASSET_JS);
// -----------------------------------------------------------------------
// DEFINE URL PATHS
// -----------------------------------------------------------------------
if (US === DS) { // needed for compatibility with windows
define("HTTP_PATH_BASE", HTTP_PATH_ROOT . RELATIVE_PATH_BASE);
define("HTTP_PATH_APP", HTTP_PATH_ROOT . RELATIVE_PATH_APP);
define("HTTP_PATH_LIBRARY", false);
define("HTTP_PATH_HELPERS", false);
define("HTTP_PATH_TEMPLATE", false);
define("HTTP_PATH_CONFIG", false);
define("HTTP_PATH_PAGES", false);
define("HTTP_PATH_ASSET", HTTP_PATH_ROOT . RELATIVE_PATH_ASSET);
define("HTTP_PATH_ASSET_IMG", HTTP_PATH_ROOT . RELATIVE_PATH_ASSET_IMG);
define("HTTP_PATH_ASSET_CSS", HTTP_PATH_ROOT . RELATIVE_PATH_ASSET_CSS);
define("HTTP_PATH_ASSET_JS", HTTP_PATH_ROOT . RELATIVE_PATH_ASSET_JS);
} else {
define("HTTP_PATH_BASE", HTTP_PATH_ROOT .
str_replace(DS, US, RELATIVE_PATH_BASE));
define("HTTP_PATH_APP", HTTP_PATH_ROOT .
str_replace(DS, US, RELATIVE_PATH_APP));
define("HTTP_PATH_LIBRARY", false);
define("HTTP_PATH_HELPERS", false);
define("HTTP_PATH_TEMPLATE", false);
define("HTTP_PATH_CONFIG", false);
define("HTTP_PATH_PAGES", false);
define("HTTP_PATH_ASSET", HTTP_PATH_ROOT .
str_replace(DS, US, RELATIVE_PATH_ASSET));
define("HTTP_PATH_ASSET_IMG", HTTP_PATH_ROOT .
str_replace(DS, US, RELATIVE_PATH_ASSET_IMG));
define("HTTP_PATH_ASSET_CSS", HTTP_PATH_ROOT .
str_replace(DS, US, RELATIVE_PATH_ASSET_CSS));
define("HTTP_PATH_ASSET_JS", HTTP_PATH_ROOT .
str_replace(DS, US, RELATIVE_PATH_ASSET_JS));
}
// -----------------------------------------------------------------------
// DEFINE REQUEST PARAMETERS
// -----------------------------------------------------------------------
define("REQUEST_QUERY",
isset($_SERVER["QUERY_STRING"]) && $_SERVER["QUERY_STRING"] != '' ?
$_SERVER["QUERY_STRING"] : false);
define("REQUEST_METHOD",
isset($_SERVER["REQUEST_METHOD"]) ?
strtoupper($_SERVER["REQUEST_METHOD"]) : false);
define("REQUEST_STATUS",
isset($_SERVER["REDIRECT_STATUS"]) ?
$_SERVER["REDIRECT_STATUS"] : false);
define("REQUEST_PROTOCOL",
isset($_SERVER["HTTP_ORIGIN"]) ?
substr($_SERVER["HTTP_ORIGIN"], 0,
strpos($_SERVER["HTTP_ORIGIN"], '://') + 3) : 'http://');
define("REQUEST_PATH",
isset($_SERVER["REQUEST_URI"]) ?
str_replace(RELATIVE_PATH_BASE, '',
$_SERVER["REQUEST_URI"]) : '_UNKNOWN_');
define("REQUEST_PATH_STRIP_QUERY",
REQUEST_QUERY ?
str_replace('?' . REQUEST_QUERY, '', REQUEST_PATH) : REQUEST_PATH);
// -----------------------------------------------------------------------
// DEFINE SITE PARAMETERS
// -----------------------------------------------------------------------
define("PRODUCTION", false);
define("PAGE_PATH_DEFAULT", US . 'index');
define("PAGE_PATH",
(REQUEST_PATH_STRIP_QUERY === US) ?
PAGE_PATH_DEFAULT : REQUEST_PATH_STRIP_QUERY);
If you add the above code to your own project, outputting all user constants at this point (which you can do with get_defined_constants(true) should give a result that looks somewhat like this :
array (
'LOCAL_PATH_BOOTSTRAP' => '/var/www/libraries/backend/Data/examples',
'URL_SEPARATOR' => '/',
'DS' => '/',
'PS' => ':',
'US' => '/',
'RELATIVE_PATH_ROOT' => '',
'LOCAL_PATH_ROOT' => '/var/www',
'HTTP_PATH_ROOT' => 'localhost:8888',
'RELATIVE_PATH_BASE' => '/libraries/backend/Data/examples',
'RELATIVE_PATH_APP' => '/libraries/backend/Data',
'RELATIVE_PATH_LIBRARY' => '/libraries/backend/Data/vendor',
'RELATIVE_PATH_HELPERS' => '/libraries/backend/Data/examples',
'RELATIVE_PATH_TEMPLATE' => '/libraries/backend/Data/examples/templates',
'RELATIVE_PATH_CONFIG' => '/libraries/backend/Data/examples/config',
'RELATIVE_PATH_PAGES' => '/libraries/backend/Data/examples/pages',
'RELATIVE_PATH_ASSET' => '/libraries/backend/Data/examples/assets',
'RELATIVE_PATH_ASSET_IMG' => '/libraries/backend/Data/examples/assets/img',
'RELATIVE_PATH_ASSET_CSS' => '/libraries/backend/Data/examples/assets/css',
'RELATIVE_PATH_ASSET_JS' => '/libraries/backend/Data/examples/assets/js',
'LOCAL_PATH_BASE' => '/var/www/libraries/backend/Data/examples',
'LOCAL_PATH_APP' => '/var/www/libraries/backend/Data',
'LOCAL_PATH_LIBRARY' => '/var/www/libraries/backend/Data/vendor',
'LOCAL_PATH_HELPERS' => '/var/www/libraries/backend/Data/examples',
'LOCAL_PATH_TEMPLATE' => '/var/www/libraries/backend/Data/examples/templates',
'LOCAL_PATH_CONFIG' => '/var/www/libraries/backend/Data/examples/config',
'LOCAL_PATH_PAGES' => '/var/www/libraries/backend/Data/examples/pages',
'LOCAL_PATH_ASSET' => '/var/www/libraries/backend/Data/examples/assets',
'LOCAL_PATH_ASSET_IMG' => '/var/www/libraries/backend/Data/examples/assets/img',
'LOCAL_PATH_ASSET_CSS' => '/var/www/libraries/backend/Data/examples/assets/css',
'LOCAL_PATH_ASSET_JS' => '/var/www/libraries/backend/Data/examples/assets/js',
'HTTP_PATH_BASE' => 'localhost:8888/libraries/backend/Data/examples',
'HTTP_PATH_APP' => 'localhost:8888/libraries/backend/Data',
'HTTP_PATH_LIBRARY' => false,
'HTTP_PATH_HELPERS' => false,
'HTTP_PATH_TEMPLATE' => false,
'HTTP_PATH_CONFIG' => false,
'HTTP_PATH_PAGES' => false,
'HTTP_PATH_ASSET' => 'localhost:8888/libraries/backend/Data/examples/assets',
'HTTP_PATH_ASSET_IMG' => 'localhost:8888/libraries/backend/Data/examples/assets/img',
'HTTP_PATH_ASSET_CSS' => 'localhost:8888/libraries/backend/Data/examples/assets/css',
'HTTP_PATH_ASSET_JS' => 'localhost:8888/libraries/backend/Data/examples/assets/js',
'REQUEST_QUERY' => false,
'REQUEST_METHOD' => 'GET',
'REQUEST_STATUS' => false,
'REQUEST_PROTOCOL' => 'http://',
'REQUEST_PATH' => '/',
'REQUEST_PATH_STRIP_QUERY' => '/',
'PRODUCTION' => false,
'PAGE_PATH_DEFAULT' => '/index',
'PAGE_PATH' => '/index',
)
回答4:
You can access the $_SERVER['DOCUMENT_ROOT'] variable :
<?php
$path = $_SERVER['DOCUMENT_ROOT'];
$path .= "/subdir1/yourdocument.txt";
?>
回答5:
The best way to do this given your setup is to define a constant describing the root path of your site. You can create a file config.php at the root of your application:
<?php
define('SITE_ROOT', dirname(__FILE__));
$file_path = SITE_ROOT . '/Texts/MyInfo.txt';
?>
Then include config.php in each entry point script and reference SITE_ROOT in your code rather than giving a relative path.
回答6:
use dirname(__FILE__) in a global configuration file.
回答7:
The best way Using dirname(). Because SERVER['DOCUMENT_ROOT'] not working all servers, and also return server running path.
$root = dirname( __FILE__ );
$root = __DIR__;
$filePath = realpath(dirname(__FILE__));
$rootPath = realpath($_SERVER['DOCUMENT_ROOT']);
$htmlPath = str_replace($root, '', $filePath);
来源：https://stackoverflow.com/questions/11604445/php-absolute-path-to-root