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(PHP 4, PHP 5)
is_file — Prüft, ob der Dateiname eine reguläre Datei ist
Prüft, ob der Dateiname eine reguläre Datei ist.
Pfad zur Datei.
Gibt TRUE zurück, wenn der Dateiname existiert und eine reguläre Datei ist, sonst FALSE.
Beispiel #1 is_file()-Beispiel
<?php
var_dump(is_file('eine_datei.txt')) . "\n";
var_dump(is_file('/usr/bin/')) . "\n";
?>
Das oben gezeigte Beispiel erzeugt folgende Ausgabe:
bool(true) bool(false)
Upon failure, an E_WARNING is emitted.
Hinweis: Die Ergebnisse dieser Funktion werden gecached. Weitere Details erhalten Sie bei clearstatcache().
Seit PHP 5.0.0 kann diese Funktion mit einigen URL-Wrappern benutzt werden. Schauen Sie in der Liste unter Supported Protocols and Wrappers nach, welcher Wrapper die Funktionalität von stat() unterstützt.
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 use
C:/foldertowww/site/file.ext
so I preform an str_replace('\\', '/', $path)
Sometimes I have had the \ instead of / work. (this is using apache2 on XP)
but for sure you cannot have mixed separators.
this is a simple way to find specific files instead of using is_file().
this example is made for mac standards, but easily changed for pc.
<?php
function isfile($file){
return preg_match('/^[^.^:^?^\-][^:^?]*\.(?i)' . getexts() . '$/',$file);
//first character cannot be . : ? - subsequent characters can't be a : ?
//then a . character and must end with one of your extentions
//getexts() can be replaced with your extentions pattern
}
function getexts(){
//list acceptable file extensions here
return '(app|avi|doc|docx|exe|ico|mid|midi|mov|mp3|
mpg|mpeg|pdf|psd|qt|ra|ram|rm|rtf|txt|wav|word|xls)';
}
echo isfile('/Users/YourUserName/Sites/index.html');
?>
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);
}
}
}
}
}
?>
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.
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.
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;
}
?>
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.
?>
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);
?>
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.
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
?>
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).
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';
?>
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.
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)
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)!
### 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.
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.
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, $pos + 1);
}
}
?>
I do a lot of file parsing and have found the following technique extremely useful:
while (false !== ($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 != '..' && $ext[1]=='doc')
if you're running apache as a service on a win32 machine, an you try to determinate if a file on an other pc in your network exists - ex.: is_file('//servername/share/dir1/dir2/file.txt') - you may return false when you're running the service as LocalSystem. To avoid this, you have to start the Apache-Service as a 'registered' domain user.
In PHP 4.1.0 under win32, this seems to print out a warning message if the file does not exist (using error_reporting = E_ALL & ~E_NOTICE).
It seems that is_file doesn't return true for a file that is 0 bytes. Perhaps it is something with the file system. I am using IIS 3.0 on an NT4 box. I worked around it using !is_dir($filename) but that seems a clunky way to do it.
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