PHP: file_exists

file_exists

stefan at horn dot nl
11-Jul-2006 11:30


file_exists and safe_mode



file_exists under safe_mode works (I work with for php 4) doesn't work when owner of the dir where the file stands differs from the php-owner. 



e.g. file_exists in this dir will give FALSE nevertheless the file exists



rights           owner   dir

drwxr-xr-x    apache  images



change the owner of the dir to the phpowner and file_exists works.



I spent too much time to discover. Hope it will spare a lot of your time. 



Stefan

sirarthur at sirarthur dot info
10-May-2006 12:04


The following code will rename an uploaded image to a MD5 hash with a rand number added of its name and check wheter a file with same hash already exists or not:



<?php

$file = $HTTP_POST_FILES['file'];

$image=new Image($imgfld,$file);

if($image->FType != null){

if ($image->FType=="image/gif") {

$ext = ".gif";

}else{

$ext = ".jpg";

}

 $nfile = md5($image->Name . rand());

while(file_exists($imgfld . $nfile . $ext) == true){

 $nfile = md5($image->Name . rand());

}

 $image->ResizedWidth = $imggrx;

 $image->ResizedHeight = $imggry;

 $image->Resample($nfile);

?>



It uses an image class found at phpclasses.org

pilotdoofy at gmail dot com
22-Apr-2006 01:35


I wrote a very simple function that allows you to search a folder for a file name with a regular expression. It can handle both PREG and EREG regexps and can accept different case sensitivities for EREG regexps.



function regExpFile($regExp, $dir, $regType='P', $case='') {

# Two parameters accepted by $regType are E for ereg* functions

# and P for preg* functions

$func = ( $regType == 'P' ) ? 'preg_match' : 'ereg' . $case;



# Note, technically anything other than P will use ereg* functions;

# however, you can specify whether to use ereg or eregi by

# declaring $case as "i" to use eregi rather than ereg



$open = opendir($dir);

while( ($file = readdir($open)) !== false ) {

if ( $func($regExp, $file) ) {

return true;

}

} // End while

return false;

} // End function



Basically if you supply anything but "P" for $regType it will assume you're using EREG regexps. The case should only be blank or "i".

hiro at arkusa dot com
07-Feb-2006 01:23


As of php 5.0.4, many (if not all) php file manipulation functions fail if a file's size is no smaller than 2GB (i.e. 2^31) on the x86 platforms. Even file_exists() fails (always returns FALSE). This puzzled me when I was writing a video file manipulation application.



A simple alternative is like:



function file_exists_2gb($filename) {

    system("test -f $filename", $rval);

    return ($rval == 0);

}

07-Jan-2006 01:08


I wrote this little handy function to check if an image exists in a directory, and if so, return a filename which doesnt exists e.g. if you try 'flower.jpg' and it exists, then it tries 'flower[1].jpg' and if that one exists it tries 'flower[2].jpg' and so on. It works fine at my place. Ofcourse you can use it also for other filetypes than images.



<?php

function imageExists($image,$dir) {



    $i=1; $probeer=$image;



    while(file_exists($dir.$probeer)) {

        $punt=strrpos($image,".");

        if(substr($image,($punt-3),1)!==("[") && substr($image,($punt-1),1)!==("]")) {

            $probeer=substr($image,0,$punt)."[".$i."]".

            substr($image,($punt),strlen($image)-$punt);

        } else {

            $probeer=substr($image,0,($punt-3))."[".$i."]".

            substr($image,($punt),strlen($image)-$punt);

        }

        $i++;

    }

    return $probeer;

}

?>

Fabrizio (staff at bibivu dot com)
21-Dec-2005 06:11


here a function to check if a certain URL exist:

<?php

    function url_exists($url) {

        $a_url = parse_url($url);

        if (!isset($a_url['port'])) $a_url['port'] = 80;

        $errno = 0;

        $errstr = '';

        $timeout = 30;

        if(isset($a_url['host']) && $a_url['host']!=gethostbyname($a_url['host'])){

            $fid = fsockopen($a_url['host'], $a_url['port'], $errno, $errstr, $timeout);

            if (!$fid) return false;

            $page = isset($a_url['path'])  ?$a_url['path']:'';

            $page .= isset($a_url['query'])?'?'.$a_url['query']:'';

            fputs($fid, 'HEAD '.$page.' HTTP/1.0'."\r\n".'Host: '.$a_url['host']."\r\n\r\n");

            $head = fread($fid, 4096);

            fclose($fid);

            return preg_match('#^HTTP/.*\s+[200|302]+\s#i', $head);

        } else {

            return false;

        }

    }

?>



in my CMS, I am using it with those lines:

<?php

        if(!isset($this->f_exist[$image]['exist']))

            if(strtolower(substr($fimage,0,4)) == 'http' || strtolower(substr($fimage,0,4)) == 'www.'){

                if(strtolower(substr($image,0,4)) == 'www.'){

                    $fimage = 'http://'.$fimage;

                    $image = 'http://'.$image;

                }

                $this->f_exist[$image]['exist'] = $this->url_exists($fimage); //for now

            } else {

                $this->f_exist[$image]['exist'] = ($fimage!='' && file_exists($fimage) && is_file($fimage) && is_readable($fimage) && filesize($fimage)>0);

            }

        }

?>

flobee
13-Dec-2005 04:24


file_exists overwrites the last access (atime) !

try:

if (@fclose(@fopen( $file, "r"))) {

                     // true;

                 } else {

                     // false;

                 }

to check if important for you

ihoss dot com at gmail dot com
19-Oct-2005 07:37


The following script checks if there is a file with the same name and adds _n to the end of the file name, where n increases. if img.jpg is on the server, it tries with img_0.jpg, checks if it is on the server and tries with img_1.jpg.

<?php 

  $img = "images/".$_FILES['bilde']['name'];

  $t=0;

  while(file_exists($img)){

    $img = "images/".$_FILES['bilde']['name'];

    $img=substr($img,0,strpos($img,"."))."_$t".strstr($img,".");

    $t++;

  }

  move_uploaded_file($_FILES['bilde']['tmp_name'], $img);

?>

phenbach at phenbach dot com
19-Sep-2005 03:37


I recently had an issue with PLESK and copying file to other directories with the move_uploaded file function.



This would work on every linux server except plesk servers. I could figure it out and have yet to find out.  I had to create a work a round and decided to use the exec() function.



As noted above the file_exist() function must need to wait for some time and I found the looking function a waste of resouces and didn't work for me anyway. So this is what I came up with.



function cp($source,$destination){



$cmd="cp -u ".$source ." ".$destination; //create the command string to copy with the update option

exec($cmd); //exec command

$cmd_test="ls -la ".$destination; //list file 

exec($cmd_test,$out); 

//If the file is present it $out[0] key will contain the file info. 

//if it is not present it will be null

if (isset($out[0])){

     return true; 

}else{

     return false;

}

    }

davidc at php dot net
13-Sep-2005 01:05


Also while using the file_exists file, please make sure you do not start using stuff like,



<?php



if(file_exists($_GET['file'] . '.php')) {

    include($_GET['file'] . '.php';

}



?>



you could use something like this..



<?php

    $inrep = "./";

    $extfichier = ".php";

    $page = $inrep.basename(strval($_REQUEST["page"]),$extfichier).extfichier;

    if(file_exist($page)) {

        include($page);

    }

?>



or even hardcode it.



  So since pretty much all commercial server(s) have url_fopen on.. you can imagine that file_exists($_GET['file']. '.php') 

is rather .. unsecure :)



-David Coallier

tma at 2p dot cz
24-Aug-2005 01:47


If checking for a file newly created by an external program in Windows then file_exists() does not recognize it immediately.  Iy seems that a short timeout may be required.



<?

    $file = 'file.tmp';

    if ($h = popen("start \"bla\" touch $file", "r")) {

      pclose($h);

   // now I would like know if a file was created

   // note: usleep not supported 

      $start = gettimeofday();   

      while (!file_exists(trim($file, " '\""))) {

        $stop = gettimeofday();

        if ( 1000000 * ($stop['sec'] - $start['sec']) + $stop['usec'] - $start['usec'] > 500000) break;  // wait a moment

     }



     if (file_exists($file))   // now should be reliable

?>

09-Aug-2005 07:20


That is true feshi. But, if you have your server configured correctly, those access logs will only be accessible by an admin or the root account. The webuser account that runs the php script will be unable to start reading from that file. That's the easiest fix.

feshi
04-Aug-2005 03:34


this code looks inocent



<?php

$filename=$_REQUEST["var"];

$filename .= ".data";

file_exist($filename){

  include($filename);

}

?>



but if you pass something like script.php?var=test%00asbs

it should really can do bad things like including accesslog files if you replace "test" with something like "../logs/accesslog"

joe dot knall at gmx dot net
15-Mar-2005 03:59


concerning file_exists and safe_mode:

if safe_mode=ON and $file (in safe_mode_include_dir) is not owned by the user who executes file_exists($file), file_exists returns FALSE but still $file can be included;

I could handle this by setting safe_mode_gid=On and appropriate group-ownership

07-Mar-2005 02:00


Nathaniel, you should read the manual carefuly next time prior to posting anything here, as all you indicated is the fact you missed the idea of the include_path. To remind - include_path is for some functions only, mainly intended for include and require to simpify include/require operations (kinda way the #include works). It is NOT for any filesystem function, which would be damn annoying than helpful, which is quite understandable and obvious.

andrewNOSPAMPLEASE at abcd dot NOSPAMERSca
11-Feb-2005 05:29


file_exists will have trouble finding your file if the file permissions are not read enabled for 'other' when not owned by your php user. I thought I was having trouble with a directory name having a space in it (/users/andrew/Pictures/iPhoto Library/AlbumData.xml) but the reality was that there weren't read permissions on Pictures, iPhoto Library or AlbumData.xml. Once I fixed that, file_exists worked.

Nathaniel
08-Feb-2005 09:08


I spent the last two hours wondering what was wrong with my if statement: file_exists($file) was returning false, however I could call include($file) with no problem.



It turns out that I didn't realize that the php include_path value I had set in the .htaccess file didn't carry over to file_exists, is_file, etc.



Thus:



<?PHP

// .htaccess php_value include_path '/home/user/public_html/';



// includes lies in /home/user/public_html/includes/



//doesn't work, file_exists returns false

if ( file_exists('includes/config.php') )

{

     include('includes/config.php');

}



//does work, file_exists returns true

if ( file_exists('/home/user/public_html/includes/config.php') )

{

    include('includes/config.php');

}

?>



Just goes to show that "shortcuts for simplicity" like setting the include_path in .htaccess can just cause more grief in the long run.

ceo at l-i-e dot com
02-Dec-2004 03:44


Prior to 4.3.2, and 4.3.3 with open_basedir, this function generated an error/warning message when the file/directory in question did not exist.

aidan at php dot net
10-Apr-2004 09:46


If you'd like to check if a file exists anywhere your include path, have a look at this function:





http://aidan.dotgeek.org/lib/?file=function.file_exists_incpath.php

alex at raynor nospam dot ru
05-Apr-2004 08:16


If you use open_basedir in php.ini and use file_exists for file outside open_basedir path, you will not be warned at log and file_exists returns false even if file really exists.

11-Feb-2004 06:32


On nix systems file_exists will report a link that doesn't point to a valid file as non-existant, ie: the link itself exists but the file it points to does not.  Using is_link will report true whether the link points to a valid file or not.

file_exists

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