is_file

Note that is_file() returns false if the parent directory doesn't have +x set for you; this make sense, but other functions such as readdir() don't seem to have this limitation. The end result is that you can loop through a directory's files but is_file() will always fail.

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:<?phpinclude('foobar/bar.php');?>and bar.php looks like this:<?phpecho (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.

### 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 -qwill print "y".is_dir resolves symlinks too.

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);?>

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.

is_file doesn't recognize files whose filenames contain strange characters like czech ů or russian characters in general.I've seen many scripts that take it for granted that a path is a directory when it fails is_file($path). When trying to determine whether a path links to a file or a dir, you should always use is_dir after getting false from is_file($path). For cases like described above, both will fail.

sometimes this function does not work because permission , you can use this function that check if the path has dot in last will return true . public function isFile($file) {        $f = pathinfo($file, PATHINFO_EXTENSION);        return (strlen($f) > 0) ? true : false;    }  isfile('http://www.ip4t.net/image.jpg');you should replace a string between '' with your file path to check

It took me a day or so to figure out that is_file() actually looks for a valid $ existing path/file in string form. It is not performing a pattern-like test on the parameter given. Its testing to see if the given parameter leads to a specific  existing 'name.ext' or other (non-directory) file type object.

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)<?phpfunction is_file_lfs($path){    exec('[ -f "'.$path.'" ]', $tmp, $ret);    return $ret == 0;}?>

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.

This Function deletes everything in a defined Folder:
Works with PHP 4 and 5.

<?php
  function deletefolder($path)
  {
    if ($handle=opendir($path)) 
    {
      while (false!==($file=readdir($handle))) 
      {
        if ($file<>"." AND $file<>"..")
        {
          if (is_file($path.'/'.$file))
          {
            @unlink($path.'/'.$file);
          }
          if (is_dir($path.'/'.$file))
          {
            deletefolder($path.'/'.$file);
            @rmdir($path.'/'.$file);
          }
        }
      }
    }
  }
?>

I have noticed that using is_file on windows servers (mainly for development) to use a full path c:\ doesn't always work.I have had to useC:/foldertowww/site/file.extso I preform an str_replace('\\', '/', $path)Sometimes I have had the \ instead of / work. (this is using apache2 on XP)but for sure you cannot have mixed separators.

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 filedefine('DIR_ROOT', dirname(__FILE__));// in other files, prefix paths with the constantrequire(DIR_ROOT . '/relative/to/bootstrap.php');?>or if you have to use a relative path:<?phprequire(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.<?phpecho __FILE__;// /www/site.com/public/index.phpecho dirname(__FILE__);// /www/site.com/publicecho dirname(dirname(__FILE__));// /www/site.com?>

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)

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).

Note also that if is_file(), (and also is_dir()), will return false if you have the open_basedir configuration set and the file (or directory) is not in one of the configured locations. Essentially as the other notes offer, if you don't have permissions to access the file or dir these functions return false but this is also another use case that one may overlook.

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

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.

I see, is_file not work properly on specifical file in /dev (linux)look : root@boofh:/data# php -r "var_dump(is_file('/dev/core'));"bool(true)root@boofh:/data# php -r "var_dump(is_file('/proc/kcore'));"bool(true)root@boofh:/data# ls -alh /proc/kcore-r-------- 1 root root 128T Aug 13 18:39 /proc/kcoreOR FIND do not detect regular file.root@boofh:/data# find /dev/ -type froot@boofh:/data#// version of php :root@boofh:/data# php -vPHP 5.4.4-14+deb7u3 (cli) (built: Jul 17 2013 14:54:08)Copyright (c) 1997-2012 The PHP GroupZend Engine v2.4.0, Copyright (c) 1998-2012 Zend Technologies

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.phpyour 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);    }}?>

Today I got the in the comments already described behaviour that between directory and file can't be distinguished by is_file() or is_dir().A dirty and incomplete hack is below, incomplete because it never includes links and I never tested what happens when a directory is not allowed to be read.$items = scandir($dir);foreach ($items as $item){    if ($item!='.' && $item!='..'){        $deep = @scandir($dir.'/'.$item);        echo ($deep ? '[DIR] ':'[FILE] '.$item.nl2br(PHP_EOL);    }}