is_file
(PHP 4, PHP 5, PHP 7, PHP 8)
is_file — 通常ファイルかどうかを調べる
パラメータ
filename-
ファイルへのパス。
戻り値
ファイルが存在し、かつそれが通常のファイルである場合に true、
それ以外の場合に false を返します。
注意: PHP の数値型は符号付整数であり、 多くのプラットフォームでは 32 ビットの整数を取るため、 ファイルシステム関数の中には 2GB より大きなファイルについては期待とは違う値を返すものがあります。
エラー / 例外
失敗したときは E_WARNING が発生します。
例
例1 is_file() の例
<?php
var_dump(is_file('a_file.txt')) . "\n";
var_dump(is_file('/usr/bin/')) . "\n";
?>上の例の出力は以下となります。
bool(true) bool(false)
注意
注意: この関数の結果は キャッシュされます。詳細は、clearstatcache() を参照してください。
ヒント
PHP 5.0.0 以降、この関数は、
何らかの URL ラッパーと組合せて使用することができます。
どのラッパーが stat() ファミリーをサポートしているかを調べるには
サポートするプロトコル/ラッパー を参照してください。
＋add a note
User Contributed Notes 22 notes
Anonymous ¶
12 years ago
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.
Anonymous ¶
19 years ago
### 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 ¶
20 years ago
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.
cristian dot ban at neobytesolutions com ¶
17 years ago
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);
?>
andreas dot stagl at fits dot at ¶
22 years ago
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.
Anonymous ¶
13 years ago
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.
www.ip4t.net - abdelrahman nourallah ¶
9 years ago
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
rigrace at swbell dot net ¶
16 years ago
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.
gizmo at gizmo dot sk ¶
16 years ago
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 $ret == 0;
}
?>
Jonathan Shaltz ¶
19 years ago
Maybe this is a newbie mistake, but note that paths are relative to the filesystem and the location of the script. This means that MS IIS virtual directories are not available by relative path - use an absolute.
This threw me because virtual directories ARE available for URLs, at least on IIS.
Kevin Gregull ¶
16 years ago
This Function deletes everything in a defined Folder:
Works with PHP 4 and 5.
<?php
function deletefolder($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);
}
}
}
}
}
?>
bill fumerola ¶
19 years ago
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)
quietust at ircN dot org ¶
23 years ago
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).
don dot duvall at deduvall dot com ¶
15 years ago
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('\\', '/', $path)
Sometimes I have had the \ instead of / work. (this is using apache2 on XP)
but for sure you cannot have mixed separators.
samuel at jch-optimize dot net ¶
2 years ago
Note also that if is_file(), (and also is_dir()), will return false if you have the open_basedir configuration set and the file (or directory) is not in one of the configured locations.
Essentially as the other notes offer, if you don't have permissions to access the file or dir these functions return false but this is also another use case that one may overlook.
tatarynowicz at gmail dot com ¶
18 years ago
An easy way not to have to choose between hard-coding full paths and using relative paths is either via this line:
<?php
// in the bootstrap file
define('DIR_ROOT', dirname(__FILE__));
// in other files, prefix paths with the constant
require(DIR_ROOT . '/relative/to/bootstrap.php');
?>
or if you have to use a relative path:
<?php
require(dirname(__FILE__) . '/relative/to/this_file.php');
?>
This way all your paths will be absolute, yet you can move the application anywhere in the filesystem.
BTW, each successive call to dirname takes you one step up in the directory tree.
<?php
echo __FILE__;
// /www/site.com/public/index.php
echo dirname(__FILE__);
// /www/site.com/public
echo dirname(dirname(__FILE__));
// /www/site.com
?>
sy well-known-sign damla.net ¶
16 years ago
In 32 bit environments, these functions including is_file(), stat() filesize() will not work due to PHPs default integer being signed. So anything above ~2.1 billion bytes you actually get a negative value.
This is actually a bug but I dont think there is an easy workaround. Try to switch to 64 bit.
rlh at d8acom dot com ¶
21 years ago
I do a lot of file parsing and have found the following technique extremely useful:
while (false !== ($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')
rehfeld.us ¶
20 years ago
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);
}
}
?>