is_link

is_executable

Last updated: Fri, 08 Aug 2008

is_file

(PHP 4, PHP 5)

is_file — Tells whether the filename is a regular file

Description

bool is_file ( string $filename )

Tells whether the given file is a regular file.

Parameters

filename: Path to the file.

Return Values

Returns TRUE if the filename exists and is a regular file, FALSE otherwise.

Examples

Example #1 is_file() example


<?php
var_dump(is_file('a_file.txt')) . "\n";
var_dump(is_file('/usr/bin/')) . "\n";
?>

The above example will output:

bool(true)
bool(false)

Notes

Note: The results of this function are cached. See clearstatcache() for more details.

Tip

As of PHP 5.0.0, this function can also be used with some URL wrappers. Refer to List of Supported Protocols/Wrappers for a listing of which wrappers support stat() family of functionality.


In 32 bit environments, these functions including is_file(), stat() filesize() will not work due to PHPs default integer being signed. So anything above ~2.1 billion bytes you actually get a negative value.



This is actually a bug but I dont think there is an easy workaround. Try to switch to 64 bit.

gizmo at gizmo dot sk
22-Feb-2008 09:50


here is a workaround for the file size limit. uses bash file testing operator, so it may be changed to test directories etc.  (see http://tldp.org/LDP/abs/html/fto.html for possible test operators)



<?php

function is_file_lfs($path){

    exec('[ -f "'.$path.'" ]', $tmp, $ret);

    return $ret == 0;

}

?>

Guilherme guilherme at gmail dot com
17-Jul-2007 01:36


If you are trying to get the extension of the file. I have the following piece of code for you:



<?php

$extension = substr($file_name, strrpos($file_name, "."));



// That code must get the correctly extension in any cases.

?>

cristian dot ban at neobytesolutions com
27-Jun-2007 08:46


regarding note from rehfeld dot us : 



In my experience the best( and easiest ) way to find the extension of a file is : 



<?php



// use this when you are sure it actually has an extension.

$extension = end(explode(".", $file_name));



?>



or 



<?php



// this one will also check if it actually has an extension

$parts = explode(".", $file_name);

if (is_array($parts) && count($parts) > 1)

    $extension = end($parts);



?>

riki1512 / a_t / gmx / d_ot / de
07-Feb-2007 11:22


Be careful with big files. I get a 



Warning: is_file(): Stat failed for all.rar (errno=75 - Value too large for defined data type) in /.../test.php on line 3



and FALSE as result for a file of 3,5 GB.

tatarynowicz at gmail dot com
18-Oct-2006 02:35


An easy way not to have to choose between hard-coding full paths and using relative paths is either via this line:



<?php

// in the bootstrap file

define('DIR_ROOT', dirname(__FILE__));

// in other files, prefix paths with the constant

require(DIR_ROOT . '/relative/to/bootstrap.php');

?>



or if you have to use a relative path:



<?php

require(dirname(__FILE__) . '/relative/to/this_file.php');

?>



This way all your paths will be absolute, yet you can move the application anywhere in the filesystem.



BTW, each successive call to dirname takes you one step up in the directory tree.



<?php

echo __FILE__;

// /www/site.com/public/index.php

echo dirname(__FILE__);

// /www/site.com/public

echo dirname(dirname(__FILE__));

// /www/site.com

?>

SimonCharest at gmail dot com
08-Aug-2006 05:39


In rlh's example, "$ext=explode('.',$document);" is only good if you consider that the filename only possesses a single dot (".") and that it is right before the extension. You should get the last dot's position with the strRPos() function instead.



Another note : some files might not even have an extension (i.e.: mostly under Linux/Unix).

Emin Sadykhov (azdg_nospam at azdg dot com)
12-Dec-2005 01:57


File operations such as is_file (also is_dir, opendir, readdir) work slower with Absolute paths - processing time is increase in 2-3 times. 



Current rule is actual only for PHP5 (tested on 5.0.4, 5.1.1, Windows and Linux, 1st and 2nd Apache)



Try to use relative paths in these operators.



Example tested on my machine:

<?php

# note: in the both conditions file really exists!



# WIN XP, PHP4

# processing time: ~ 0.0003 sec.

if(is_file("images/10.jpg")) echo 'file exists';



# processing time: ~ 0.0002 sec. !!!

if(is_file("C:/server/htdocs/mysite/images/10.jpg")) echo 'file exists';



# WIN XP, PHP5

# processing time: ~ 0.0004 sec.

if(is_file("images/10.jpg")) echo 'file exists';



# processing time: ~ 0.0010 sec.

if(is_file("C:/server/htdocs/mysite/images/10.jpg")) echo 'file exists';

?>

Jonathan Shaltz
14-Oct-2005 05:23


Maybe this is a newbie mistake, but note that paths are relative to the filesystem and the location of the script.  This means that MS IIS virtual directories are not available by relative path - use an absolute.

This threw me because virtual directories ARE available for URLs, at least on IIS.

bill fumerola
31-Aug-2005 01:45


be careful, is_file() fails on files larger than your integer storage (2^32 for most).



Warning: is_file(): Stat failed for bigfile (errno=75 - Value too large for defined data type)

punknroll at gmx dot at
11-Aug-2005 03:11


is_file returns false if you don't have the permissions for the file or the directory (eg.: you are web34 and the directory belongs to root)!

08-Mar-2005 05:02


### Symbolic links are resolved ###



If you pass a symlink (unix symbolic link) as parameter, is_file will resolve the symlink and will give information about the refered file. For example:



  touch file

  ln -s file link

  echo '<? if (is_file("link")) echo "y\n"; ?>' | php -q



will print "y".



is_dir resolves symlinks too.

ludvig dot ericson at gmail dot com
25-Oct-2004 06:06


I tend to use alot of includes, and I found that the is_file is based on the script executed, not ran.

if you request /foo.php and foo.php looks like this:

<?php

include('foobar/bar.php');

?>

and bar.php looks like this:

<?php

echo (is_file('foo/bar.txt'));

?>



Then PHP (on win32, php 5.x) would look for /foo/bar.txt and not /foobar/foo/bar.txt.

you would have to rewrite the is_file statement for that, or change working directory.

Noting this since I sat with the problem for some time,



cheers, Toxik.

rehfeld.us
03-Sep-2004 10:04


regarding rlh at d8acom dot com method,



It is incorrect. Well, it works but you are not guaranteed the file extension using that method.



for example :   filename.inc.php



your method will tell you the ext is "inc", but it is in fact "php"



heres a way that will work properly.



<?php



$dh = opendir($dir);



while (false !== ($document = readdir($dh))) {

    $pos = strrpos($document, '.');

    if (false !== $pos && strlen($document) > $pos + 1) {

        $ext = substr($document, $pos + 1);

    }

}



?>

rlh at d8acom dot com
12-Feb-2003 01:17


I do a lot of file parsing and have found the following technique extremely useful:



while (false !== ($document = readdir($my_dir))) 

{

    $ext=explode('.',$document);

    if($document != '.' && $document != '..' && $ext[1])

    {

                       'Do something to file...'

              }

}



It gets around the fact that, when working on website pages, the html files are read as directories when downloaded. It also allows you to extend the usefulness of the above method by adding the ability to determine file types e.g.



if($document != '.' && $document != '..' && $ext[1]=='htm')

or

if($document != '.' && $document != '..' && $ext[1]=='doc')

andreas dot stagl at fits dot at
27-Mar-2002 07:34


if you're running apache as a service on a win32 machine, an you try to determinate if a file on an other pc in your network exists - ex.: is_file('//servername/share/dir1/dir2/file.txt') - you may return false when you're running the service as LocalSystem. To avoid this, you have to start the Apache-Service as a 'registered' domain user.

quietust at ircN dot org
14-Dec-2001 04:20


In PHP 4.1.0 under win32, this seems to print out a warning message if the file does not exist (using error_reporting = E_ALL & ~E_NOTICE).

amraam at ao dot net
12-Mar-2000 02:56


It seems that is_file doesn't return true for a file that is 0 bytes.  Perhaps it is something with the file system.  I am using IIS 3.0 on an NT4 box.  I worked around it using !is_dir($filename) but that seems a clunky way to do it.

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