php教程

dirname

(PHP 4, PHP 5, PHP 7)

dirname返回路径中的目录部分

说明

dirname ( string $path ) : string

给出一个包含有指向一个文件的全路径的字符串,本函数返回去掉文件名后的目录名。

参数

path

一个路径。

在 Windows 中,斜线(/)和反斜线(\)都可以用作目录分隔符。在其它环境下是斜线(/)。

返回值

返回 path 的父目录。 如果在 path 中没有斜线,则返回一个点('.'),表示当前目录。否则返回的是把 path 中结尾的 /component(最后一个斜线以及后面部分)去掉之后的字符串。

更新日志

版本 说明
5.0.0 dirname() 的操作从 PHP 5.0.0 版开始是二进制安全的。
4.0.3 在这个版本中,dirname() 被修正为 POSIX 兼容。

范例

Example #1 dirname() 例子

<?php
echo "1) " dirname("/etc/passwd") . PHP_EOL// 1) /etc
echo "2) " dirname("/etc/") . PHP_EOL// 2) / (or \ on Windows)
echo "3) " dirname("."); // 3) .
?>

注释

Note:

dirname() operates naively on the input string, and is not aware of the actual filesystem, or path components such as "..".

Note:

dirname() is locale aware, so for it to see the correct directory name with multibyte character paths, the matching locale must be set using the setlocale() function.

Note:

Since PHP 4.3.0, you will often get a slash or a dot back from dirname() in situations where the older functionality would have given you the empty string.

检查下面发生变化的例子:

<?php

// PHP 4.3.0 以前
dirname('c:/'); // 返回 '.'

// PHP 4.3.0 以后
dirname('c:/x'); // 返回 'c:'
dirname('c:/Temp/x'); // 返回 'c:/Temp'
dirname('/x'); // 返回 '\'

?>

参见

User Contributed Notes

bobray at softville dot com 28-Dec-2018 05:04
Be aware that if you call dirname(__FILE__) on Windows, you may get backslashes. If you then try to use str_replace() or preg_replace() to replace part of the path using forward slashes in your search pattern, there will be no match. You can normalize paths with $path = str_replace('\\',  '/' ,$path) before doing any transformations
qeremy (!) gmail 13-Dec-2015 01:01
After PHP 7;
<?php
print dirname("/usr/local/lib", 2); # /usr
?>

Before PHP 7;
<?php
print dirname(dirname("/usr/local/lib")); # /usr

# or
function dirname_with_levels($path, $levels = 1) {
    while (
$levels--) {
       
$path = dirname($path);
    }
    return
$path;
}
print
dirname_with_levels("/usr/local/lib", 2); # /usr
?>
y dot a dot dejong at singular dot of dot alumni dot utwente dot nl 22-Oct-2014 07:51
As of PHP 5.3.0, you can use __DIR__ as a replacement for dirname(__FILE__)
iam at shaz3e dot com 11-Mar-2014 01:34
File located locally in: F:\localhost\www\Shaz3e-ResponsiveFramework\S3-CMS\_source

Localhost Path: http://s3lab.com/Shaz3e-ResponsiveFramework/S3-CMS/_source/

Example 1: dirname($_SERVER['PHP_SELF']); //output:  /Shaz3e-ResponsiveFramework/S3-CMS/_source

Example 2: "http://".$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']); //output:  http://s3lab.com/Shaz3e-ResponsiveFramework/S3-CMS/_source

Example 3: $_SERVER['HTTP_HOST'] . dirname($_SERVER['PHP_SELF']); //output:  s3lab.com/Shaz3e-ResponsiveFramework/S3-CMS/_source
frederikreiss at gmx dot de 11-Sep-2013 09:55
what about a recursive dirname. To get $count levels up in a directory.

<?php

function r_dirname($path, $count=1){
    if (
$count > 1){
       return
dirname(r_dirname($path, --$count));
    }else{
       return
dirname($path);
    }
}
Yousef Ismaeil Cliprz 18-Feb-2013 02:39
You can get best root path if you want to call a file from you project paths.

Make sure this define in your www/index.php

or the core file that inside www/ root.

<?php

/**
 * @def (string) DS - Directory separator.
 */
define("DS","/",true);

/**
 * @def (resource) BASE_PATH - get a base path.
 */
define('BASE_PATH',realpath(dirname(__FILE__)).DS,true);

?>

You can call any file any time without any problems

<?php

include BASE_PATH.'inc/class.php';

?>
minimalist at intelligence dot com 10-Mar-2012 05:33
If you want to get the parent parent directory of your script, you can use this:

<?php
 
//Example script path: home/content/en/script.php
 
$parentparentdir=basename(dirname(dirname(__FILE__)));
 echo
$parentparentdir; //will output 'content'
?>
nhl261 at yahoo dot com 26-Jun-2011 08:54
As usual, to include or require a file, we use this
<?php
require dirname(__FILE__) . DIRECTORY_SEPARATOR . 'my_file.php';
?>

in rare case, we have current file existing at the root directory, dirname would return C:\ or / , then the line above contains 2 slashes \\ or //
To handle this this case, we use rtrim to clear slashes.
<?php
require rtrim(dirname(__FILE__), '/\\') . DIRECTORY_SEPARATOR . 'my_file.php';
?>

Also, another use of dirname is to get virtual directory (url path), the issue is the same as above, we have to check and process before concatenating strings
subzey at immelman dot ru 07-Sep-2010 09:51
In some situations (I can't locate the dependencies) basename and dirname may return incorrect values if parsed string is in UTF-8.

Like, dirname("glossary/задний-фокус") will return "glossary" and basename("glossary/задний-фокус") will return "-фокус".

Quickfix is
str_replace("!$!", "", dirname(str_replace("/", "!$!/!$!", $q)))
webyazilimci84 at gmail dot com 25-Nov-2009 06:06
In my mvc based framework i make BASE_PATH and BASE_URL definitions like the following and both work well in the framework without problem.

index.php :

define('BASE_PATH',realpath('.'));
define('BASE_URL', dirname($_SERVER["SCRIPT_NAME"]));

BASE_PATH is for server side inclusions.
BASE_URL is for client side inclusions (scripts, css files, images etc.)
ken dot forslund at hp dot com 29-May-2009 01:33
A key problem to hierarchical include trees is that PHP processes include paths relative to the original file, not the current including file.

A solution to that, is to prefix all include paths with:
<?php str_replace('//','/',dirname(__FILE__)); ?>

this will generate a base path relative to the current file, which will then allow an include behavior similar to C/C++.

thus, to include a file that is 1 in the parent directory:
<?php require_once( str_replace('//','/',dirname(__FILE__).'/') .'../parent.php'); ?>

to include a file that is in the same directory:
<?php require_once( str_replace('//','/',dirname(__FILE__).'/') .'neighbor.php'); ?>

to include a file that is in a subdirectory:
<?php require_once( str_replace('//','/',dirname(__FILE__).'/') .'folder/sub.php'); ?>

Notice that all paths we reference must NOT begin with a /, and must be relative to the current file, in order to concatenate correctly.
joe dot naylor at gmail dot com 13-Dec-2008 10:07
The dirname function does not usually return a slash on the end, which might encourage you to create links using code like this:
$url = dirname($_SERVER['PHP_SELF']) . '/somepage.php';

However dirname returns a slash if the path you specify is the root, so $url in that case would become '//somepage.php'.  If you put that URL as the action on a form, for example, submitting the form will try to go to http://somepage.php.

I ran into this when I wrote a site on a url with a path, www.somehost.com/client/somepage.php, where the code above works great, but then wanted to put it on a subdomain, client.somehost.com/somepage.php, where things started breaking.

The best solution would be to create a function that generates absolute URLs and use that throughout the site, but creating a safe_dirname function (and an htaccess rewrite to fix double-slashes just in case) fixed the issue for me:

<?php
function safe_dirname($path)
{
  
$dirname = dirname($path);
   return
$dirname == '/' ? '' : $dirname;
}
?>
Tom 20-Jul-2008 11:13
Expanding on Anonymous' comment, this is not necessarily correct. If the user is using a secure protocol, this URL is inaccurate. This will work properly:

<?php

// Is the user using HTTPS?
$url = (isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] == 'on')) ? 'https://' : 'http://';

// Complete the URL
$url .= $_SERVER['HTTP_HOST'] . dirname($_SERVER['PHP_SELF']);

// echo the URL
echo $url;

?>
Anonymous 04-Jun-2008 01:01
A simple way to show the www path to a folder containing a file...

echo "http://".$_SERVER['HTTP_HOST'].dirname($_SERVER['PHP_SELF']);
rmahase at gmail dot com 11-May-2008 11:31
this little function gets the top level public directory

eg. http://www.mysite.com/directory1/file.php

or http://www.mysite.com/directory1/directory2/directory3/file.php

will both return "directory1" ...which is the top level directory

<?php
function public_base_directory()
{
   
//get public directory structure eg "/top/second/third"
   
$public_directory = dirname($_SERVER['PHP_SELF']);
   
//place each directory into array
   
$directory_array = explode('/', $public_directory);
   
//get highest or top level in array of directory strings
   
$public_base = max($directory_array);
   
    return
$public_base;
}
?>
ts at dev dot websafe dot pl 23-Mar-2008 03:55
Inside of script.php I needed to know the name of the containing directory. For example, if my script was in '/var/www/htdocs/website/somedir/script.php' i needed to know 'somedir' in a unified way.

The solution is:
<?php
$containing_dir
= basename(dirname(__FILE__));
?>
Zingus J. Rinkle 10-Sep-2007 10:55
Most mkpath() function I saw listed here seem long and convoluted.
Here's mine:

<?php
 
function mkpath($path)
  {
    if(@
mkdir($path) or file_exists($path)) return true;
    return (
mkpath(dirname($path)) and mkdir($path));
  }
?>

Untested on windows, but dirname() manual says it should work.
hans111 at yahoo dot com 26-Jan-2007 04:25
The same function but a bit improved, will use REQUEST_URI, if not available, will use PHP_SELF and if not available will use __FILE__, in this case, the function MUST be in the same file. It should work, both under Windows and *NIX.

<?php
function my_dir(){
    return
end(explode('/', dirname(!empty($_SERVER['REQUEST_URI']) ? $_SERVER['REQUEST_URI'] : !empty($_SERVER['PHP_SELF']) ? $_SERVER['PHP_SELF'] : str_replace('\\','/',__FILE__))));
}

?>
Xedecimal at gmail dot com 24-Oct-2006 11:35
Getting absolute path of the current script:

<?php
dirname
(__FILE__)
?>

Getting webserver relative path of the current script...

<?php
function GetRelativePath($path)
{
   
$npath = str_replace('\\', '/', $path);
    return
str_replace(GetVar('DOCUMENT_ROOT'), '', $npath);
}
?>

later on

<?php
GetRelativePath
(dirname(__FILE__));
?>

If anyone has a better way, get to the constructive critisism!
legolas558 dot sourceforge comma net 10-Jul-2006 06:52
The best way to get the absolute path of the folder of the currently parsed PHP script is:

<?php

if (DIRECTORY_SEPARATOR=='/')
 
$absolute_path = dirname(__FILE__).'/';
else
 
$absolute_path = str_replace('\\', '/', dirname(__FILE__)).'/';

?>

This will result in an absolute unix-style path which works ok also on PHP5 under Windows, where mixing '\' and '/' may give troubles.

[EDIT by danbrown AT php DOT net: Applied author-supplied fix from follow-up note.]
renich at woralelandia dot com 10-Aug-2005 10:15
--- Edited by tularis@php.net ---
You could also have a look at the getcwd() function
--- End Edit ---

A nice "current directory" function.

function current_dir()
{
$path = dirname($_SERVER[PHP_SELF]);
$position = strrpos($path,'/') + 1;
print substr($path,$position);
}

current_dir();

I find this usefull for a lot of stuff! You can maintain a modular site with dir names as modules names. At least I would like PHP guys to add this to the function list!

If there is anything out there like it, please tell me.
klugg this-is-junk at tlen dot pl 18-Jul-2005 07:14
Attention with this. Dirname likes to mess with the slashes.
On Windows, Apache:

<?php
echo '$_SERVER[PHP_SELF]: ' . $_SERVER['PHP_SELF'] . '<br />';
echo
'Dirname($_SERVER[PHP_SELF]: ' . dirname($_SERVER['PHP_SELF']) . '<br>';
?>

prints out

$_SERVER[PHP_SELF]: /index.php
Dirname($_SERVER[PHP_SELF]: \
tobylewis at mac dot com 24-Jun-2005 06:52
Since the paths in the examples given only have two parts (e.g. "/etc/passwd") it is not obvious whether dirname returns the single path element of the parent directory or whether it returns the whole path up to and including the parent directory.  From experimentation it appears to be the latter.

e.g.

dirname('/usr/local/magic/bin');

returns '/usr/local/magic'  and not just 'magic'

Also it is not immediately obvious that dirname effectively returns the parent directory of the last item of the path regardless of whether the last item is a directory or a file.  (i.e. one might think that if the path given was a directory then dirname would return the entire original path since that is a directory name.)

Further the presense of a directory separator at the end of the path does not necessarily indicate that last item of the path is a directory, and so

dirname('/usr/local/magic/bin/');  #note final '/'

would return the same result as in my example above.

In short this seems to be more of a string manipulation function that strips off the last non-null file or directory element off of a path string.
27-Apr-2005 03:31
If you merely want to find out wether a certain file is located within or underneath a certain directory or not, e.g. for White List validation, the following function might be useful to you:

<?php
 
function in_dir ($file, $in_dir)
  {
     
$dir    = realpath ($file);
     
$in_dir = realpath ($in_dir);

      if (!
is_dir ($file)) {
         
$dir = dirname ($file);
      }

      do {
          if (
$dir === $in_dir) {
             
$is_in_dir = TRUE;
              break;
          }
      } while (
$dir !== ($dir = dirname ($dir)));

      return (bool) @
$is_in_dir;
  }
?>
soywiz at hotmail dot com 01-Jan-2004 06:41
You can use it to get parent directory:

dirname(dirname(__FILE__))

...include a file relative to file path:

include(dirname(__FILE__) . '/path/relative/file_to_include.php');

..etc.
andrey at php dot net 14-Jan-2003 07:02
Code for write permissions check:

<?php
error_reporting
(E_ALL);
$dir_name = '/var/www/virtual/phpintra/htdocs/php/';
do {
   
$b_is_writable = is_writable($dir_name);
    echo
sprintf("Dir[%s]Writable[%s]\n", $dir_name, $b_is_writable? 'YES':'NO');
}while ((
$dir_name = dirname($dir_name)) !='/');
?>
rudecoder at yahoo dot com 11-Jan-2003 12:43
dirname can be used to create self referencing web scripts with the following one liner.

<?php
$base_url
= str_replace($DOCUMENT_ROOT, "", dirname($PHP_SELF));
?>

Using this method on a file such as:

/home/mysite/public_html/wherever/whatever.php

will return:

/wherever

Now $base_url can be used in your HTML to reference other scripts in the same directory.

Example:

href='<?=$base_url?>/myscript.php'
dave at corecomm dot us 08-Jan-2003 10:20
I very much appreciated Fredrich Echol's suggestion (rwf at gpcom dot net) of how to find a base path, but found that it failed when the initial script was already in the root folder -- dirname('/rootscript.php')=='/' and dirname('/include/includescript.php')=='/include' which have the same number of slashes. This variation is what I'm now using:

<?php
if (!defined("BASE_PATH")) define('BASE_PATH', dirname($_SERVER['SCRIPT_NAME'])=='/' ? './' : str_repeat("../"substr_count(dirname($_SERVER["SCRIPT_NAME"]), "/")));
?>

This explicitly checks for the root path (/) and uses './' as the base path if we're in the root folder.
I put this at/near the top of any file that calls another. (I used define for my own convenience; should work just fine with variables and without testing to see if you already did it.)

Note that in both cases (root-folder script and non-root-folder script), BASE_PATH will include a trailing slash. At least with Apache on Darwin (Mac OS X), you can include(BASE_PATH.'/myfile.php'); and the doubled slash won't cause any problems, giving the same result as include(BASE_PATH.'myfile.php'); .
tapken at engter dot de 30-Apr-2002 12:09
To get the directory of current included file:

<?php
dirname
(__FILE__);
?>

For example, if a script called 'database.init.php' which is included from anywhere on the filesystem wants to include the script 'database.class.php', which lays in the same directory, you can use:

<?php
include_once(dirname(__FILE__) . '/database.class.php');
?>

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