assert
this function errors out as the dl() cannot take the absolute path..."Warning: dl() [function.dl]: Temporary module name should contain only filename in /home/..."
dl
(PHP 4, PHP 5)
dl — Belirtilen PHP eklentisini çalışma anında yükler
Açıklama
int dl
( string $kütüphane
)
Kütüphane dosyası kütüphane değiştirgesi ile belirtilen PHP eklentisini yükler.
Belli bir eklentinin yüklü olup olmadığını sınamak için, hem yerleşik (php.ini ile yüklenen) hem de devingen olarak (dl() ile) yüklenen eklentileri bulan extension_loaded() işlevini kullanın.
Uyarı
Bu işlevin kullanımı PHP 5.3.0'dan beri ÖNERİLMEMEKTEDİR ve PHP 6.0.0'da tamamen KALDIRILMIŞTIR. Bu işleve kesinlikle güvenmemelisiniz.
Değiştirgeler
- eklenti
-
Bu değiştirge ile eklentinin platforma özgü kütüphane dosyasının ismi belirtilir. Örneğin sockets eklentisini Windows platformunda yüklemek için php_sockets.dll ismini kullanmak gerekirken Unix platformlarında sockets.so kullanmak gerekir (bir paylaşımlı modül olarak derlenmişse).
Eklentinin yükleneceği dizin platforma göre değişiklik gösterir:
Windows - php.ini içinde açıkça belirtilmemişse, eklenti öntanımlı olarak c:\php4\extensions\ dizininden yüklenir.
Unix - php.ini içinde açıkça belirtilmemişse, öntanımlı eklenti dizinin yeri şunlara bağlıdır:
- PHP'nin --enable-debug seçeneği ile derlenip derlenmediği;
- PHP'nin (deneysel) ZTS (Zend Thread Safety) desteği ile derlenip derlenmediği;
- geçerli yerleşik ZEND_MODULE_API_NO sabiti (Zend yerleşik modülü API numarası; genelde API modülünün değişiklik tarihidir. 20010901 gibi).
Dönen Değerler
Başarı durumunda TRUE, başarısızlık durumunda FALSE döner. Eğer modül yükleme işlevsel değilse
(enable_dl ile iptal edilmiş veya php.ini içinde
safe_mode etkin kılınmışsa) bir E_ERROR iletisi
çıktılanıp çalışma durdurulur. Eğer işlev, kütüphane yüklenemediğinden
dolayı başarısız olursa bir E_WARNING iletisi
çıktılayarak FALSEdöndürür.
Örnekler
Örnek 1 - dl() örnekleri
<?php
// Platforma göre eklenti yüklemek
if (!extension_loaded('sqlite')) {
if (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') {
dl('php_sqlite.dll');
} else {
dl('sqlite.so');
}
}
// PHP 4.3.0 ve sonrası için PHP_SHLIB_SUFFIX sabiti de kullanılabilir
if (!extension_loaded('sqlite')) {
$prefix = (PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '';
dl($prefix . 'sqlite.' . PHP_SHLIB_SUFFIX);
}
?>
Sürüm Bilgisi
| Sürüm: | Açıklama |
|---|---|
| 5.3.0 | Artık CLI, CGI ve Embed hariç tüm SAPI'lerde bir E_DEPRECATED üretiliyor. |
Notlar
Bilginize:
dl() işlevi çok evreli HTTP sunucularında desteklenmez. Böyle bir ortamda çalışıyorsanız php.ini içinde extensions deyimini kullanın. Ancak, CGI ve CLI sürümleri bundan etkilenmez.
Bilginize:
PHP 5'ten beri, dl() işlevinin CLI dışında kullanımı önerilmemektidir. Yerine Eklenti Yükleme Yönergelerini kullanın.
Bilginize:
PHP 6'dan beri bu işlev CLI, CGI ve embed dışında kalan tüm SAPI'lerde kaldırılmıştır.
Bilginize:
dl() işlevinin değiştirgesi Unix platformlarında harf büyüklüğüne duyarlıdır.
Bilginize: Bu işlev, PHP güvenli kipte çalışırken iptal edilir.
Ayrıca Bakınız
- Eklenti Yükleme Yönergeleri
- extension_loaded() - Belirtilen eklenti yüklü mü diye bakar
add a note
User Contributed Notes
dl
Anonymous
04-Dec-2010 10:36
CLI workaround
18-Feb-2009 03:18
NOTE: This only works using the CLI
If you need to use dl() with the CLI, but you get this warning:
"PHP Warning: dl(): Dynamically loaded extensions aren't enabled"
Then the 'enable_dl' setting in the php.ini needs to be set to 'On' - the set_ini() function does not work with this INI option.
If, however, you do not wish (or don't have access) to alter the system php.ini, then you can do the following:
<?php
if ( !ini_get('enable_dl') ) {
exec("php -d enable_dl=On $argv[0]");
exit;
}
?>
This simply calls itself and defines the enable_dl INI entry on the command line so you dont have to start the script with options in the first place (or use another script to call it.)
shaunspiller at spammenot-gmail dot com
29-Jan-2009 12:34
dl is awkward because the filename format is OS-dependent and because it can complain if the extension is already loaded. This wrapper function fixes that:
<?php
function load_lib($n, $f = null) {
return extension_loaded($n) or dl(((PHP_SHLIB_SUFFIX === 'dll') ? 'php_' : '') . ($f ? $f : $n) . '.' . PHP_SHLIB_SUFFIX);
}
?>
Examples:
<?php
// ensure we have SSL and MySQL support
load_lib('openssl');
load_lib('mysql');
// a rare few extensions have a different filename to their extension name, such as the image (gd) library, so we specify them like this:
load_lib('gd', 'gd2');
?>
buildsmart at daleenterprise dot com
29-Dec-2006 01:33
I recently came across this under PHP 4.4.4, it seems that the dl(); function generates an error/warning about registering the function if a test is done on an extension that is pre-loaded in the php.ini file (extension=gd.so).
<?php
$gd_is_shared = "shared-library";
if (function_exists('ImageCreateFromPNG') && !@dl('gd.so')) {
$gd_is_shared = "embedded";
}
print $gd_is_shared;
?>
The only purpose of this test is to determine if it is an embedded extension or a loaded extension.
I don't see this error occur under PHP 5.1.6 or PHP 5.2.0.
The test platform is Mac OS X 10.3.9 and Mac OS X 10.4.8
docey
30-Dec-2005 09:37
just some note to loading modules, they do not have to
be executable.
some examples below check for this but if an module is
not executable is does not mean you cant use it. it just
needs to be readable NOT executable.
although some modules might need this perhaps for some
reason i cannot think of, so here an example,
<?php
// fails to load mysql although it could be loaded.
if(is_executable("mysql.so")){
dl("mysql.so");
}
// loads mysql
if(is_readable("mysql.so")){
dl("mysql.so");
}
?>
watch out with this, as you can see mysql.so would not be
loaded and the script would fail. because its checked for
executable permissions although these are not needed.
mag_2000 at front dot ru
06-Dec-2005 11:13
<?php
function dl_local( $extensionFile ) {
//make sure that we are ABLE to load libraries
if( !(bool)ini_get( "enable_dl" ) || (bool)ini_get( "safe_mode" ) ) {
die( "dh_local(): Loading extensions is not permitted.\n" );
}
//check to make sure the file exists
if( !file_exists( $extensionFile ) ) {
die( "dl_local(): File '$extensionFile' does not exist.\n" );
}
//check the file permissions
if( !is_executable( $extensionFile ) ) {
die( "dl_local(): File '$extensionFile' is not executable.\n" );
}
//we figure out the path
$currentDir = getcwd() . "/";
$currentExtPath = ini_get( "extension_dir" );
$subDirs = preg_match_all( "/\//" , $currentExtPath , $matches );
unset( $matches );
//lets make sure we extracted a valid extension path
if( !(bool)$subDirs ) {
die( "dl_local(): Could not determine a valid extension path [extension_dir].\n" );
}
$extPathLastChar = strlen( $currentExtPath ) - 1;
if( $extPathLastChar == strrpos( $currentExtPath , "/" ) ) {
$subDirs--;
}
$backDirStr = "";
for( $i = 1; $i <= $subDirs; $i++ ) {
$backDirStr .= "..";
if( $i != $subDirs ) {
$backDirStr .= "/";
}
}
//construct the final path to load
$finalExtPath = $backDirStr . $currentDir . $extensionFile;
//now we execute dl() to actually load the module
if( !dl( $finalExtPath ) ) {
die();
}
//if the module was loaded correctly, we must bow grab the module name
$loadedExtensions = get_loaded_extensions();
$thisExtName = $loadedExtensions[ sizeof( $loadedExtensions ) - 1 ];
//lastly, we return the extension name
return $thisExtName;
}//end dl_local()
?>
james at gogo dot co dot nz
18-Jul-2005 04:30
WARNING: enable_dl/dl()
*********************
There is an exploit circulating currently which takes advantage of dl() to inject code into Apache which causes all requests to all virtual hosts to be redirected to a page of the attackers choice.
All operators of shared web hosting servers with Apache and PHP should disable dl() by setting enable_dl to off otherwise your servers are vulnerable to this exploit.
This exploit is generally known as flame.so (the object that is loaded into Apache) and flame.php (the php script that loads it).
Google gives more information:
http://www.google.co.nz/search?q=flame.so+flame.php
endofyourself at yahoo dot com
18-Oct-2003 04:12
If you need to load an extension from the CURRENT local directory because you do not have privelages to place the extension in your servers PHP extensions directory, this function i wrote may be of use to you
<?php
/*
Function: dl_local()
Reference: http://us2.php.net/manual/en/function.dl.php
Author: Brendon Crawford <endofyourself |AT| yahoo>
Usage: dl_local( "mylib.so" );
Returns: Extension Name (NOT the extension filename however)
NOTE:
This function can be used when you need to load a PHP extension (module,shared object,etc..),
but you do not have sufficient privelages to place the extension in the proper directory where it can be loaded. This function
will load the extension from the CURRENT WORKING DIRECTORY only.
If you need to see which functions are available within a certain extension,
use "get_extension_funcs()". Documentation for this can be found at
"http://us2.php.net/manual/en/function.get-extension-funcs.php".
*/
function dl_local( $extensionFile ) {
//make sure that we are ABLE to load libraries
if( !(bool)ini_get( "enable_dl" ) || (bool)ini_get( "safe_mode" ) ) {
die( "dh_local(): Loading extensions is not permitted.\n" );
}
//check to make sure the file exists
if( !file_exists( $extensionFile ) ) {
die( "dl_local(): File '$extensionFile' does not exist.\n" );
}
//check the file permissions
if( !is_executable( $extensionFile ) ) {
die( "dl_local(): File '$extensionFile' is not executable.\n" );
}
//we figure out the path
$currentDir = getcwd() . "/";
$currentExtPath = ini_get( "extension_dir" );
$subDirs = preg_match_all( "/\//" , $currentExtPath , $matches );
unset( $matches );
//lets make sure we extracted a valid extension path
if( !(bool)$subDirs ) {
die( "dl_local(): Could not determine a valid extension path [extension_dir].\n" );
}
$extPathLastChar = strlen( $currentExtPath ) - 1;
if( $extPathLastChar == strrpos( $currentExtPath , "/" ) ) {
$subDirs--;
}
$backDirStr = "";
for( $i = 1; $i <= $subDirs; $i++ ) {
$backDirStr .= "..";
if( $i != $subDirs ) {
$backDirStr .= "/";
}
}
//construct the final path to load
$finalExtPath = $backDirStr . $currentDir . $extensionFile;
//now we execute dl() to actually load the module
if( !dl( $finalExtPath ) ) {
die();
}
//if the module was loaded correctly, we must bow grab the module name
$loadedExtensions = get_loaded_extensions();
$thisExtName = $loadedExtensions[ sizeof( $loadedExtensions ) - 1 ];
//lastly, we return the extension name
return $thisExtName;
}//end dl_local()
?>
tychay at php dot net
05-Jul-2003 08:15
MacOS makes a distinction between dynamically loadable shared libraries and loadable modules of code (bundles). The former has an extension .dylib and the latter has an extension .so. The former is in Mac-O and the latter is in ELF.
Thus PHP's extensions are built as .so whereas the symbol PHP_SHLIB_SUFFIX is bound (currently) to .dylib. I don't think this is the correct behavior, but nonetheless, it is the behavior as of PHP-5.0.0b2-dev. Right now, the config binds to SHLIB_SUFFIX_NAME (which is correctly bound to .dylib on Mac OS X). I imagine this is related to why there is so much trouble getting dl() to work on Mac OS X. (For instance, I have no trouble phpizing in a new shared library, but when compiling in stuff as shared... much evilness!)
BTW, to get dl() to work in Mac OS X you need to install the dlcompat library (via Fink, DarwinPorts, or Gentoo ports). Remember in the case of Fink, you better make sure your environment variables are adjusted to point to where dlcompat (and your other fink libraries) are.
terry