Filesystem 函数
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PHP手册

pathinfo

(PHP 4 >= 4.0.3, PHP 5)

pathinfo — 返回文件路径的信息

说明

mixed pathinfo ( string $path [, int $options ] )

pathinfo() 返回一个关联数组包含有 path 的信息。包括以下的数组单元：dirname，basename 和 extension。

可以通过参数 options 指定要返回哪些单元。它们包括：PATHINFO_DIRNAME，PATHINFO_BASENAME 和 PATHINFO_EXTENSION。默认是返回全部的单元。如果不是要求取得所有单元，则本函数返回字符串。

Example #1 pathinfo() 例子

<?php
$path_parts = pathinfo("/www/htdocs/index.html");
echo $path_parts["dirname"] . "\n";
echo $path_parts["basename"] . "\n";
echo $path_parts["extension"] . "\n";
?>

以上例程会输出：

/www/htdocs
index.html
html

Note:

有关取得当前路径信息的说明，请阅读预定义变量一节。

参见 dirname()，basename()，parse_url() 和 realpath()。

参数

path

The path to be parsed.

options

If present, specifies a specific element to be returned; one of PATHINFO_DIRNAME, PATHINFO_BASENAME, PATHINFO_EXTENSION or PATHINFO_FILENAME.

If options is not specified, returns all available elements.

返回值

If the options parameter is not passed, an associative array containing the following elements is returned: dirname, basename, extension (if any), and filename.

Note:

If the path does not have an extension, no extension element will be returned (see second example below).

If options is present, returns a string containing the requested element.

更新日志

版本 说明
5.2.0 The PATHINFO_FILENAME constant was added.

范例

Example #2 pathinfo() Example

<?php
$path_parts = pathinfo('/www/htdocs/inc/lib.inc.php');

echo $path_parts['dirname'], "\n";
echo $path_parts['basename'], "\n";
echo $path_parts['extension'], "\n";
echo $path_parts['filename'], "\n"; // since PHP 5.2.0
?>

以上例程会输出：

/www/htdocs/inc
lib.inc.php
php
lib.inc

Example #3 pathinfo() example showing difference between null and no extension

<?php
$path_parts = pathinfo('/path/emptyextension.');
var_dump($path_parts['extension']);

$path_parts = pathinfo('/path/noextension');
var_dump($path_parts['extension']);
?>

以上例程的输出类似于：

string(0) ""

Notice: Undefined index: extension in test.php on line 6
NULL

注释

Note:

For information on retrieving the current path info, read the section on predefined reserved variables.

Note:

pathinfo() is locale aware, so for it to parse a path containing multibyte characters correctly, the matching locale must be set using the setlocale() function.

参见

Filesystem 函数
在线手册：中文 英文
PHP手册
PHP手册 - N: 返回文件路径的信息

用户评论:

Pietro Baricco (11-Feb-2012 12:00)

Use this function in place of pathinfo to make it work with UTF-8 encoded file names too

<?php
function mb_pathinfo($filepath) {
    preg_match('%^(.*?)[\\\\/]*(([^/\\\\]*?)(\.([^\.\\\\/]+?)|))[\\\\/\.]*$%im',$filepath,$m);
    if($m[1]) $ret['dirname']=$m[1];
    if($m[2]) $ret['basename']=$m[2];
    if($m[5]) $ret['extension']=$m[5];
    if($m[3]) $ret['filename']=$m[3];
    return $ret;
}
?>

admin at torntech dot com (27-Jun-2011 05:39)

pathinfo will return null if 0 or null is specified for the option argument.
So you'll need to define it's value manually if the option field is omitted, to provide the default functionality.

<?php

    public function getFileInfo($source = null, $option = null){
        if(!$option){
            //1 + 2 + 4
            $option = PATHINFO_DIRNAME + PATHINFO_BASENAME + PATHINFO_EXTENSION;
            if(defined('PATHINFO_FILENAME'))
                $option += PATHINFO_FILENAME; //8
        }
        return pathinfo($source, $option);
    }

    $obj->getFileInfo("/test/file/someFile.txt");
?>

fabiolimasouto at gmail dot com (14-Oct-2010 08:53)

Sometimes we want to get an array of each component in the pathname associated with the correspondent path to that directory. We need it for creating breadCrumbs and stuff like that. So here it goes:
<?php

/* Function parsePathComponents
    * parse through all path components
    * resolves the cross platform slash issue
    * eliminates extra redundant slashes
    * @return associative array: ComponentName=>CorrespondentPath
*/

/* Array */ function parsePathComponents($path,$endSlash=true,$base=false)
{
 for(
     $path = trim($path),
     $slash = strstr(PHP_OS,'WIN') ? '\/' : '/',
     $retArray = array(),
     $str = $temp = "",
     $x = 0;
 $char = @$path{$x}; $x++)
 {
  if(!strstr($slash,$char)) $temp .= $char;
  elseif($temp){
       $str .= $temp;
       $retArray[$temp] = $str.($endSlash ? $slash{0} : '');
       $str .= $slash{0};
       $temp = "";
  }
 }
 $base&&$temp and $retArray[$temp] = $str.$temp;
 return $retArray;
}

// Testing in WINDOWS
// NOTE: UNIX will return paths with normal slashes

// return array with path names ending with a slash
$path = '/my//stupid//path/to///some/file.php';
$pathComps = parsePathComponents($path);
print_r($pathComps);

//Array ( [my] => my\ [stupid] => my\stupid\ [path] => my\stupid\path\ [to] => my\stupid\path\to\ [some] => my\stupid\path\to\some\ )

$path = 'my/other//path/';
// return paths not ending with slash
print_r(parsePathComponents($path,false));
// Array ( [my] => my [other] => my\other [path] => my\other\path )

$path = 'my//other/path/to///file.php';
// use third argument = true: for capturing the "file.php" base
print_r(parsePathComponents($path,true,true));

//Array ( [my] => my\ [other] => my\other\ [path] => my\other\path\ [to] => my\other\path\to\ [file.php] => my\other\path\to\file.php )

?>

kc8yds at gmail dot com (18-Sep-2009 10:43)

any type of url parse_url can handle this will get the extension of

pathinfo(parse_url('URL GOES HERE',PHP_URL_PATH),PATHINFO_EXTENSION)

jjoss at mail dot ru (04-Feb-2009 06:15)

pathinfo() which can be used with UTF filenames.

<?php
  function pathinfo_utf($path)
  {
    if (strpos($path, '/') !== false) $basename = end(explode('/', $path));
    elseif (strpos($path, '\\') !== false) $basename = end(explode('\\', $path));
    else return false;
    if (empty($basename)) return false;

    $dirname = substr($path, 0, strlen($path) - strlen($basename) - 1);

    if (strpos($basename, '.') !== false)
    {
      $extension = end(explode('.', $path));
      $filename = substr($basename, 0, strlen($basename) - strlen($extension) - 1);
    }
    else
    {
      $extension = '';
      $filename = $basename;
    }

    return array
    (
      'dirname' => $dirname,
      'basename' => $basename,
      'extension' => $extension,
      'filename' => $filename
    );
  }
?>

aalaap at gmail dot com (02-Feb-2009 03:58)

Here is a simple function that gets the extension of a file. Simply using PATHINFO_EXTENSION will yield incorrect results if the path contains a query string with dots in the parameter names (for eg. &x.1=2&y.1=5), so this function eliminates the query string first and subsequently runs PATHINFO_EXTENSION on the clean path/url.

<?php
function extension($path) {
  $qpos = strpos($path, "?");

  if ($qpos!==false) $path = substr($path, 0, $qpos);
 
  $extension = pathinfo($path, PATHINFO_EXTENSION);

  return $extension;
}
?>

php [spat] hm2k.org (13-Jan-2009 12:27)

A little compat for < 5.2

<?php

function pathinfo_filename($file) { //file.name.ext, returns file.name
    if (defined('PATHINFO_FILENAME')) return pathinfo($file,PATHINFO_FILENAME);
    if (strstr($file, '.')) return substr($file,0,strrpos($file,'.'));
}

?>

php-manual at spunts dot net (24-Dec-2008 05:19)

For a good example of how platform independent this function is have a look at the different return values that Lostindream and I experienced. Mine is above and Lostindream's is below:

Array
(
    [dirname] => /www/psychicblast/images/1
    [basename] => my three girlfriends.jpg
    [extension] => jpg
)

Array
(
    [dirname] => /www/htdocs
    [basename] => index.html
    [extension] => html
    [filename] => index
)
z

benjaminhill at gmail dot com (03-Dec-2008 05:18)

A warning: this function varies depending on the platform it is being run on.  For example, pathinfo('C:\Program Files\Adobe\Reader 9.0\Reader\AcroRd32.exe') will return a different result when run through a winOS PHP platform (local development) vs. a server's UNIX-based OS.  A bit like the Locale settings, but unexpected.

Lostindream at atlas dot cz (19-Aug-2008 09:43)

at example from "qutechie at gmail dot com" you can only replace function 'strpos' with 'strrpos'. (strrpos — Find position of last occurrence of a char in a string)

It's simple. For example:
<?php

function filePath($filePath)
{
 $fileParts = pathinfo($filePath);

 if(!isset($fileParts['filename']))
 {$fileParts['filename'] = substr($fileParts['basename'], 0, strrpos($fileParts['basename'], '.'));}
 
 return $fileParts;
}
 
$filePath = filePath('/www/htdocs/index.html');
print_r($filePath);
?>

Output will be:
Array
(
    [dirname] => /www/htdocs
    [basename] => index.html
    [extension] => html
    [filename] => index
)

leons87_AT_hotmail_DOT_com (15-Aug-2008 12:47)

qutechie at gmail dot com wrote a fix for support for filename in PHP 4; however it gets it wrong whenever you have a filename with a . in it (so foo.bar.jpg would return foo instead of foo.bar).

A fix would be:
<?php
if(!isset($path_parts['filename'])){
    $reversed_filename = strrev( $path_parts['basename'] );
    $path_parts['filename'] = strrev( substr( $reversed_filename, strpos( $reversed_filename, '.' ) + 1 ) );
}
?>

The idea is that you reverse the string and create a substring that starts after the first '.' and then reverse the result.

qutechie at gmail dot com (22-Jul-2008 02:29)

Quick fix for lack of support for 'filename' in php4

<?php
$path_parts = pathinfo('/www/htdocs/index.html');

echo $path_parts['dirname'], "\n";
echo $path_parts['basename'], "\n";
echo $path_parts['extension'], "\n";
echo $path_parts['filename'], "\n"; // since PHP 5.2.0

// if php4
              if(!isset($path_parts['filename'])){
                $path_parts['filename'] = substr($path_parts['basename'], 0,strpos($path_parts['basename'],'.'));
              }

?>

christian dot reinecke at web dot de (24-Feb-2008 03:46)

if you call pathinfo with a filename in url-style (example.php?with=parameter), make sure you remove the given parameters before, otherwise they will be returned as part of the extension.

extension => php?with=parameter

tom at foo-bar dot co dot uk (30-Jan-2008 02:48)

Note that this function seems to just perform string operations, and will work even on a non-existent path, e.g.

<?php
print_r(pathinfo('/no/where/file.txt'));
?>

which will output:
Array
(
    [dirname] => /no/where
    [basename] => file.txt
    [extension] => txt
    [filename] => file
)

OakBehringer (28-Jan-2008 01:47)

Building on David Blinco's function, the following will:

1. Return the correct protocol for secure requests (https)
2. Throw an exception for invalid files
3. Ensure the returned url separates directories with forward slashes (David's will not on Windows systems).

function mapPath ($filepath) {
    $realpath = realpath($filepath);
    $dir;
   
    // Verify that the path passed is real and harvest the bottom directory
    if (is_file($realpath)) {
        $dir = dirname($realpath);
    }
    elseif (is_dir($realpath)) {
        $dir = $realpath;
    }
    else {
        throw new Exception('File does not exist: ' . $realpath);
    }

    // Make sure the path is not lower than the server root
    if (strlen($dir) < strlen($_SERVER['DOCUMENT_ROOT']))
        throw new Exception("Cannot create http path below server http root.");
       
    $path = ((isset($_SERVER['HTTPS']) && strtolower($_SERVER['HTTPS']) != 'off') ? 'https' : 'http') . '://' . $_SERVER['HTTP_HOST'] . substr($realpath, strlen($_SERVER['DOCUMENT_ROOT']));
   
    if (DIRECTORY_SEPARATOR == '\\')
        $path = str_replace('\\', '/', $path);

    return $path;
}

davidblinco at gmail dot com (26-Jan-2008 03:27)

This function is not perfect, but you can use it to convert a relative path to a URL.
Please email me if you can make any improvements.

<?php
function mapURL($relPath) {
    $filePathName = realpath($relPath);
    $filePath = realpath(dirname($relPath));
    $basePath = realpath($_SERVER['DOCUMENT_ROOT']);
   
    // can not create URL for directory lower than DOCUMENT_ROOT
    if (strlen($basePath) > strlen($filePath)) {
        return '';
    }
   
    return 'http://' . $_SERVER['HTTP_HOST'] . substr($filePathName, strlen($basePath));
}
?>

henrik at not-an-address dot com (21-Dec-2007 06:23)

If you have filename with utf-8 characters, pathinfo will strip them away:

print_r(pathinfo("/mnt/files/飞儿乐团光茫.mp3"));

 .. will display:

Array
(
    [dirname] => /mnt/files
    [basename] => .mp3
    [extension] => mp3
    [filename] =>
)

mrnemesis at ntlworld dot com (19-Dec-2007 03:22)

Note that in PHP 4 (if you're stuck using it), pathinfo only provides dirname, basename, and extension, but not filename. This function will not split a file's stem and extension for you.

anders.jenbo()pc.dk (11-Sep-2007 10:34)

Heres a funciton to get the same results from php 4+ but you will have to call pathinfo_filename() instead of pathinfo().

<?php
if(version_compare(phpversion(), "5.2.0", "<")) {
    function pathinfo_filename($path) {
        $temp = pathinfo($path);
        if($temp['extension'])
            $temp['filename'] = substr($temp['basename'],0 ,strlen($temp['basename'])-strlen($temp['extension'])-1);
        return $temp;
    }
} else {
    function pathinfo_filename($path) {
        return pathinfo($path);
    }
}
?>

avi-team at inbox dot lv (15-Jul-2007 04:14)

You shouldn't assign values as it is described in previous post
// wrong:
list( $dirname, $basename, $extension, $filename ) = array_values( pathinfo($file) );

if $file has no extension, you get wrong variable values: $extension would be assigned with 'filename' array element of pathinfo() result, but $filename - would be empty.

phpnet at whoisgregg dot com (30-May-2007 07:01)

If you want to easily assign the values returned by pathinfo to separate variable names, list isn't enough. You can use array_values() first to convert the associative array into the indexed array that list() expects:

// throws notices, variables aren't set
list( $dirname, $basename, $extension, $filename ) = pathinfo($file);

// works
list( $dirname, $basename, $extension, $filename ) = array_values( pathinfo($file) );

cochise_chiracahua at hotmail.com (25-Nov-2005 07:55)

Sometimes, it's interessant to get the basename without extension.
So, I appended a new entry 'basenameWE' (Basename Without Extension) to the returned array.

<?php

// pathinfo improved
function pathinfo_im($path) {
   
    $tab = pathinfo($path);
   
    $tab["basenameWE"] = substr($tab["basename"],0
    ,strlen($tab["basename"]) - (strlen($tab["extension"]) + 1) );
   
    return $tab;
}

$my_path = "/var/www/html/example.html";

echo "<pre>\n";
print_r( pathinfo_im($my_path) );
echo "</pre>\n";

?>

Out :

Array
(
    [dirname] => /var/www/html
    [basename] => example.html
    [extension] => html
    [basenameWE] => example
)

sgermain at icexnetworks dot com (08-Jul-2005 07:24)

It is true that if you put a directory into pathinfo, usually the extension is empty. But, if the directory name is /www/example.com/ for example, you will have the following output:

Array
(
    [dirname] => /www
    [basename] => example.com
    [extension] => com
)

So, it is the same as a file.

n0dalus (08-Feb-2005 09:47)

If a file has more than one 'file extension' (seperated by periods), the last one will be returned.
For example:
<?php
$pathinfo = pathinfo('/dir/test.tar.gz');
echo 'Extension: '.$pathinfo['extension'];
?>
will produce:
Extension: gz

and not tar.gz

(03-Dec-2004 12:39)

If you want only the file extension, use this:
<?php
$extension = substr(strrchr($filename, "."), 1);
?>
This is many times faster than using pathinfo() and getting the value from array.

rob at webdimension dot co dot uk (04-Oct-2004 02:48)

Further to my previous post.

This affects servers that run PHP as a cgi module

If you have your own server:
You can use the AcceptPathInfo directive to force the core handler to accept requests with PATH_INFO and thereby restore the ability to use PATH_INFO in server-side includes.

Further information:
http://httpd.apache.org/docs-2.0/mod/core.html#acceptpathinfo

junk at plaino dot com (19-Aug-2004 02:41)

Convert a URL to the local file path and vice versa, convert a local file path to a URL.

// this sets the sytem / or \ :
strstr( PHP_OS, "WIN") ? $slash = "\\" : $slash = "/";

// This is the location of the php file that contains this
// function. Usually this request is made to files/folders
// down the directory structure, so the php file that
// contains these functions is a good "where am i"
// reference point:
$WIMPY_BASE['path']['physical'] = getcwd();
$WIMPY_BASE['path']['www'] = "http://".$_SERVER['HTTP_HOST'];

function url2filepath($theURL){
    global $WIMPY_BASE, $slash;
    $AtheFile = explode ("/", $theURL);
    $theFileName = array_pop($AtheFile);
    $AwimpyPathWWW = explode ("/", $WIMPY_BASE['path']['www']);
    $AtheFilePath = array_values (array_diff ($AtheFile, $AwimpyPathWWW));
    if($AtheFilePath){
        $theFilePath = $slash.implode($slash, $AtheFilePath).$slash.$theFileName;
    } else {
        $theFilePath = implode($slash, $AtheFilePath).$slash.$theFileName;
    }
    return ($WIMPY_BASE['path']['physical'].$theFilePath);
}

function filepath2url ($theFilepath){
    global $WIMPY_BASE, $slash;
    $AtheFile = explode ($slash, $theFilepath);
    $theFileName = array_pop($AtheFile);
    $AwimpyPathFILE = explode ($slash, $WIMPY_BASE['path']['physical']);
    $AtheFilePath = array_values (array_diff ($AtheFile, $AwimpyPathFILE));
    $thFileURL = implode("/", $AtheFilePath)."/".$theFileName;
    return ($WIMPY_BASE['path']['www']."$thFileURL");
}

albertof at deltasoft dot com dot ar (29-May-2002 09:10)

This code is to work in index.php/var/var

if(isset($PATH_INFO)) {
      $viewcode = explode('/', $PATH_INFO);
        $num = count($viewcode);
        if($num % 2 == 0) {
            $viewcode[] = '';
            $num++;
        }
        for($i = 1; $i < $num; $i += 2) {

            $$viewcode[$i] = $viewcode[$i+1];

          }
    }

m-symons at home dot com (25-Aug-2001 03:01)

And, of course, to account for the problem noted in the first post whereby calling a directory, not a file, messes with the output of pathinfo(), you can include the following test:

if($pathinfo[extension] == "") {

$deep++;

}

Ooops...sorry for missing that.

m-symons at home dot com (25-Aug-2001 02:54)

Here's a neat wee function to grab the relative path to root (especially useful if you're using mock-directories to pass variables into scripts with mod_rewrite).  The function simply iterates through every occurence of "/" within the REQUEST_URI environment variable, appending "../" to the output for every instance:

<?php

function path_to_root($path) {

    $pathinfo = pathinfo($path);
   
    $deep = substr_count($pathinfo[dirname], "/");
   
    $path_to_root = "./";
   
    for($i = 1; $i <= $deep; $i++) {
   
        $path_to_root .= "../";
       
    }
   
    return $path_to_root;
}

path_to_root($REQUEST_URI);

?>

mikep at oeone dot com (22-Aug-2001 06:27)

If you run this on a directory, basename is the last directory in the path, dirname is the path before the final directory and extension is empty.