Filesystem Functions

See Also

For related functions, see also the Directory and Program Execution sections.

For a list and explanation of the various URL wrappers that can be used as remote files, see also Supported Protocols and Wrappers.

Table of Contents

  • basename — Returns trailing name component of path
  • chgrp — Changes file group
  • chmod — Changes file mode
  • chown — Changes file owner
  • clearstatcache — Clears file status cache
  • copy — Copies file
  • delete — See unlink or unset
  • dirname — Returns a parent directory's path
  • disk_free_space — Returns available space on filesystem or disk partition
  • disk_total_space — Returns the total size of a filesystem or disk partition
  • diskfreespace — Alias of disk_free_space
  • fclose — Closes an open file pointer
  • fdatasync — Synchronizes data (but not meta-data) to the file
  • feof — Tests for end-of-file on a file pointer
  • fflush — Flushes the output to a file
  • fgetc — Gets character from file pointer
  • fgetcsv — Gets line from file pointer and parse for CSV fields
  • fgets — Gets line from file pointer
  • fgetss — Gets line from file pointer and strip HTML tags
  • file_exists — Checks whether a file or directory exists
  • file_get_contents — Reads entire file into a string
  • file_put_contents — Write data to a file
  • file — Reads entire file into an array
  • fileatime — Gets last access time of file
  • filectime — Gets inode change time of file
  • filegroup — Gets file group
  • fileinode — Gets file inode
  • filemtime — Gets file modification time
  • fileowner — Gets file owner
  • fileperms — Gets file permissions
  • filesize — Gets file size
  • filetype — Gets file type
  • flock — Portable advisory file locking
  • fnmatch — Match filename against a pattern
  • fopen — Opens file or URL
  • fpassthru — Output all remaining data on a file pointer
  • fputcsv — Format line as CSV and write to file pointer
  • fputs — Alias of fwrite
  • fread — Binary-safe file read
  • fscanf — Parses input from a file according to a format
  • fseek — Seeks on a file pointer
  • fstat — Gets information about a file using an open file pointer
  • fsync — Synchronizes changes to the file (including meta-data)
  • ftell — Returns the current position of the file read/write pointer
  • ftruncate — Truncates a file to a given length
  • fwrite — Binary-safe file write
  • glob — Find pathnames matching a pattern
  • is_dir — Tells whether the filename is a directory
  • is_executable — Tells whether the filename is executable
  • is_file — Tells whether the filename is a regular file
  • is_link — Tells whether the filename is a symbolic link
  • is_readable — Tells whether a file exists and is readable
  • is_uploaded_file — Tells whether the file was uploaded via HTTP POST
  • is_writable — Tells whether the filename is writable
  • is_writeable — Alias of is_writable
  • lchgrp — Changes group ownership of symlink
  • lchown — Changes user ownership of symlink
  • link — Create a hard link
  • linkinfo — Gets information about a link
  • lstat — Gives information about a file or symbolic link
  • mkdir — Makes directory
  • move_uploaded_file — Moves an uploaded file to a new location
  • parse_ini_file — Parse a configuration file
  • parse_ini_string — Parse a configuration string
  • pathinfo — Returns information about a file path
  • pclose — Closes process file pointer
  • popen — Opens process file pointer
  • readfile — Outputs a file
  • readlink — Returns the target of a symbolic link
  • realpath_cache_get — Get realpath cache entries
  • realpath_cache_size — Get realpath cache size
  • realpath — Returns canonicalized absolute pathname
  • rename — Renames a file or directory
  • rewind — Rewind the position of a file pointer
  • rmdir — Removes directory
  • set_file_buffer — Alias of stream_set_write_buffer
  • stat — Gives information about a file
  • symlink — Creates a symbolic link
  • tempnam — Create file with unique file name
  • tmpfile — Creates a temporary file
  • touch — Sets access and modification time of file
  • umask — Changes the current umask
  • unlink — Deletes a file
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User Contributed Notes 8 notes

up
51
Christian
17 years ago
I just learned that, to specify file names in a portable manner, you DON'T need 'DIRECTORY_SEPARATOR' - just use '/'. This really surprised and shocked me, as until now I typed about a zillion times 'DIRECTORY_SEPARATOR' to stay platform independent - unnecessary. Don't make the same mistake.
up
1
drapeko.com
14 years ago
You have an array of directories (straightforward list of directories):

<?php
     $array
= array(
        
'/home/drapeko/var',
        
'/home/drapeko/var/y',
        
'/home/drapeko',
        
'/home',
        
'/var/libexec'
    
);
     );
?>

And you would like to transform this array to hierarchy of directories:

<?php
$array
= array (
    
'home' => array (
        
'drapeko' => array (
            
'var' => array (
                
'y' => array()
             )
         )
     ),
    
'var' => array(
        
'libexec' => array()
     )
);
?>

How can you do it?

First of all the below function will help us.

<?php
/**
* This function converts real filesystem path to the string array representation.
*
* for example,
* '/home/drapeko/var/y            will be converted to    $result_array['home']['drapeko']['var']['y']
* '/home/drapeko/var/y/file.txt   will be converted to       $result_array['home']['drapeko']['var']['y']
*
* @param $path         realpath of the directory
* @return string        string array representation of the path
*/
function pathToArrayStr($path) {
    
// TODO constants/configs?
    
$res_path = str_replace(array(':/', ':\\', '/', '\\', DIRECTORY_SEPARATOR), '/', $path);
    
// if the first or last symbol is '/' delete it (e.g. for linux)
    
$res_path = preg_replace(array("/^\//", "/\/$/"), '', $res_path);
    
// create string
    
$res_path = '[\''.str_replace('/', '\'][\'', $res_path).'\']';

     return
$res_path;
}
?>

It simply converts the real path of the file to array string representation.

How can you use this function? I know it looks like a little confusing. But it's quite simple. Consider the example below:

<?php
$result
= array();
$check = array();
foreach(
$array as $val) {
    
$str = pathToArrayStr($val, 'result');
     foreach(
$check as $ck) {
         if (
strpos($ck, $str) !== false) {
             continue
2;
         }
     }
    
$check[] = $str;
     eval(
'$result'.$str.' = array();');
}
print_r($result);
?>

Heh, how do you find it? This approach has helped me very much. I hope you will find it useful. :)
up
-2
tunnelareaten at gmail dot com
19 years ago
I made this function to search and/or display files by extension or for a string occurance in the filename. Any comments or enhancements are welcome offcourse. I'll update this function soon.

usage: list_files([string], [string], [int 1 | 0], [int 1 | 0]);

search for extension: list_files([string], [string], [0], [int 1 | 0]);
returns array: $myArray = list_files([string], [string], [0], [0]);
echo result: list_files([string], [string], [0], [1]);

search for string occurance: list_files([string], [string], [1], [int 1 | 0]);
returns array: $myArray = list_files([string], [string], [1], [0]);
echo result: list_files([string], [string], [1], [1]);

<?php

function list_files($directory, $stringSearch, $searchHandler, $outputHandler) {
$errorHandler = false;
$result = array();
if (!
$directoryHandler = @opendir ($directory)) {
  echo (
"<pre>\nerror: directory \"$directory\" doesn't exist!\n</pre>\n");
return
$errorHandler = true;
}
if (
$searchHandler === 0) {
  while (
false !== ($fileName = @readdir ($directoryHandler))) {
   if(@
substr ($fileName, - @strlen ($stringSearch)) === $stringSearch) {
    @
array_push ($result, $fileName);
   }
  }
}
if (
$searchHandler === 1) {
  while(
false !== ($fileName = @readdir ($directoryHandler))) {
   if(@
substr_count ($fileName, $stringSearch) > 0) {
    @
array_push ($result, $fileName);
   }
  }
}
if ((
$errorHandler === true) &&  (@count ($result) === 0)) {
  echo (
"<pre>\nerror: no filetype \"$fileExtension\" found!\n</pre>\n");
}
else {
 
sort ($result);
  if (
$outputHandler === 0) {
   return
$result;
  }
  if (
$outputHandler === 1) {
   echo (
"<pre>\n");
  
print_r ($result);
   echo (
"</pre>\n");
  }
}
}

?>
up
-3
Gregor Mosheh
20 years ago
This function searches a directory and returns an array of all files whose filename matches the specified regular expression. It's similar in concept to the Unix find program.

function findfile($location='',$fileregex='') {
    if (!$location or !is_dir($location) or !$fileregex) {
       return false;
    }

    $matchedfiles = array();

    $all = opendir($location);
    while ($file = readdir($all)) {
       if (is_dir($location.'/'.$file) and $file <> ".." and $file <> ".") {
          $subdir_matches = findfile($location.'/'.$file,$fileregex);
          $matchedfiles = array_merge($matchedfiles,$subdir_matches);
          unset($file);
       }
       elseif (!is_dir($location.'/'.$file)) {
          if (preg_match($fileregex,$file)) {
             array_push($matchedfiles,$location.'/'.$file);
          }
       }
    }
    closedir($all);
    unset($all);
    return $matchedfiles;
}

$htmlfiles = findfile('/some/dir','/\.(htm|html)$/');
up
-3
mitra at mitra dot biz
20 years ago
Pollard@php.net contributed this in response to a question on setting these variables ...
This option *IS* settable within your PHP scripts.
Example:

<?php
  ini_set
('auto_detect_line_endings', true);
 
$contents = file('unknowntype.txt');

 
ini_set('auto_detect_line_endings', false);
 
$content2 = file('unixfile.txt');
?>

Note, with PHP 4.3 anytime Mac files are read using fgets or file you'll need to auto_detect_line_endings since \n is otherwise assumed.  However, with PHP 5.0, stream_get_line() will allow you to specify what line ending character to read up to.

\\ Read a line from a MAC file
stream_get_line($fp, 4096, "\r");

\\ Read a line from a UNIX file
stream_get_line($fp, 4096, "\n");

\\ Read a line from a DOS file
stream_get_line($fp, 4096, "\r\n");

\\ Read a line up to any filesystem line ending
ini_set('auto_detect_line_endings', true); fgets($fp);

\\ You can also make up your own line ending characters:
\\ Read up to the first instance of ":"
stream_get_line($fp, 4096, ":");
up
-7
jdhurn at uberidx dot com
21 years ago
This is a function I use to determine if a file contains Binary information. I use this for my search engine so that it doesn't try to index files like .zip or .mp3 or any other file that doesn't contain readable information. It makes use of the Character Type Extension if it's loaded, if it's not then it uses Regular Expressions.

function is_binary($link)
{
     $tmpStr  = '';
     @$fp     = fopen($link, 'rb');
     @$tmpStr = fread($fp, 256);
     @fclose($fp);

     if($tmpStr != '')
     {
          $tmpStr = str_replace(chr(10), '', $tmpStr);
          $tmpStr = str_replace(chr(13), '', $tmpStr);

          $tmpInt = 0;

           for($i =0; $i < strlen($tmpStr); $i++)
          {
                if( extension_loaded('ctype') )
               {
                    if( !ctype_print($tmpStr[$i]) )
                         $tmpInt++;
               }
               else
               {
                   if( !eregi("[[:print:]]+", $tmpStr[$i]) )
                         $tmpInt++;
               }
           }

           if($tmpInt > 5)
                return(0);
            else
                return(1);
     }
     else
           return(0);
}
up
-7
regis at webstuff dot com dot br
20 years ago
Here is a useful function if you're having trouble writing raw bytes into a file.

It receives an integer and returns an array containing the ASCII values of the bytes on each index of the array.

function int2bytes($number){
  $byte = $number;
  $i=0;
  do{
    $dec_tmp = $byte;
   
    $byte = bcdiv($byte,256,0);
    $resto = $dec_tmp - (256 * $byte);
    $return[] = $resto;
  } while($byte >= 256);
  if($byte) $return[] = $byte;
  return array_reverse($return);
}

Example:

$arr = int2bytes(75832);

$arr will contain the following values:
Array
(
    [0] => 1
    [1] => 40
    [2] => 56
)

Now, to write this data to the file, just use a fputs() with chr(), just like this:

fputs($fp,chr($arr[0]).chr($arr[1]).chr($arr[2]))

-- Regis
up
-11
ob at babcom dot biz
11 years ago
a function based on "tunnelareaten at gmail dot com"s idea to search for files in a given directory by a searchstring or by fileextension.

I added support to search recursively through all sub-directories an to determine weather the filepath should be returned or not.

<?php
// recursive function to get contents of given folder by searchterm or fileextension
// (does not show folders)
// standards: Foldername:                    string
//            Searchterm:                    string
//            Searchtype:                    ext/search (file-extension or searchterm within filename)
//            SaveCompletePath:        true/1
// usage:     array FileSearch_r($Folder,$Search[,$SearchType,$SavePath])

function FileSearch_r($Dir,$Search,$SearchType="search",$SavePath=1) {
 
$Array=array();
 
$D=dir($Dir);
  while (
false!==($Entry=$D->read()))
    if (
$Entry!='.' && $Entry!='..') {
     
$Entry=$Dir.$Entry;
      if (
is_dir($Entry)) $Array=array_merge($Array,FileSearch_r($Entry.'/',$Search,$SearchType,$SavePath));
      else
          if (
$SearchType=="search"
                     
?substr_count($Entry,$Search)>0
                     
:($SearchType=="ext"
                         
?substr($Entry,-strlen($Search))===$Search
                         
:true))
             
$Array[]=$Entry;
    }
 
$D->close();
 
sort($Array,SORT_STRING);
  if(!(bool)
$SavePath) $Array=str_replace($Dir,"",array_values($Array));
  return
$Array;
}
?>
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