On Centos 5, and maybe other Red Hat based systems, any attempt to use file_get_contents to access a URL on an http port other than 80 (e.g. "http://www.example.com:8040/page") may fail with a permissions violation (error 13) unless the box you are running php on has its seLinux set to 'permissive' not 'enforcing' . Otherwise the request doesn't even get out of the box, i.e. the permissions violation is generated locally by seLinux.
file_get_contents
(PHP 4 >= 4.3.0, PHP 5)
file_get_contents — Lê todo o conteúdo de um arquivo para uma string
Descrição
Esta função é semelhante à file(), exceto que file_get_contents() retorna o arquivo em uma string, começando a partir de offset até maxlen bytes. Em caso de falha, file_get_contents() retornará FALSE.
file_get_contents() é o método preferível para ler o conteúdo de um arquivo em uma string. Ela usa técnicas de mapeamento de memória suportadas pelo seu SO para melhorar a performance.
Nota: Se você estiver abrindo uma URI com caracteres especiais, como espaços, você precisa codificar a URI com urlencode().
Parâmetros
- filename
-
Nome do arquivo para ler.
- flags
-
Aviso
Para todas as versões anteriores ao PHP 6, este parâmetro é chamado use_include_path e é um bool. O parâmetro flags está disponível somente a partir do PHP 6. Se você estiver usando uma versão anterior e quiser buscar o arquivo filename no include_path, este parâmetro deve ser TRUE. A partir do PHP 6, você deve usar a flag FILE_USE_INCLUDE_PATH.
O valor de flags pode ser qualquer combinação das seguintes flags (com algumas restrições), unidas com o operador binário OR (|).
Flags disponíveis Flag Descrição FILE_USE_INCLUDE_PATH Procura o arquivo filename nos diretórios de include. Veja include_path para mais informações. FILE_TEXT Se a semântica unicode estiver habilitada, o encoding padrão dos dados lidos é UTF-8. Você pode especificar um encoding diferente criando um contexto personalizado ou alterando o encoding padrão utilizando stream_default_encoding(). Esta flag não pode ser usada com FILE_BINARY. FILE_BINARY Com esta flag, o arquivo é lido em modo binário. Esta é a opção padrão e não pode ser usada com FILE_TEXT. - context
-
Um recurso de contexto válido, criado com stream_context_create(). Se você não precisa usar um contexto personalizado, você pode ignorar este parâmetro passando NULL.
- offset
-
O ponto onde a leitura deve começar.
- maxlen
-
Comprimento máximo dos dados lidos.
Valor Retornado
A função retorna os dados lidos ou FALSE em caso de falha.
Histórico
| Versão | Descrição |
|---|---|
| 5.0.0 | Adicionado suporte a contexto. |
| 5.1.0 | Adicionados os parâmetros offset e maxlen . |
| 6.0.0 | O parâmetro use_include_path foi substituído pelo parâmetro flags . |
Notas
Nota: Esta função é compatível com dados binários
Você pode usar uma URL como um nome de arquivo nesta função se fopen wrappers estiver habilitado. Veja fopen() para mais detalhes em como especificar o nome do arquivo e List of Supported Protocols/Wrappers para uma lista de protocolos URL suportados.
Quando usando SSL, o Microsoft IIS irá violar o protocolo fechando a conexão sem enviar uma notificação close_notify. O PHP acusará isso como sendo "SSL: Fatal Protocol Error" quando tentar ler os dados. Para prevenir isso, o valor de error_reporting deve ser reduzido para um nível que não inclui avisos. para o nível que não emita warnings. O PHP 4.3.7 e seguintes conseguem detectar servidores IIS defeituosos quando você abre um stream utilizando o wrapper https:// e suprimirá os avisos. Se você está usando fsockopen() para criar um socket ssl://, a responsabilidade de detectar e suprimir esse aviso passa para você.
Veja Também
- file() - Lê todo o arquivo para um array
- fgets() - Lê uma linha de um ponteiro de arquivo
- fread() - Leitura binary-safe de arquivo
- readfile() - Lê e exibe o conteúdo de um arquivo
- file_put_contents() - Escreve uma string para um arquivo
- stream_get_contents() - Reads remainder of a stream into a string
- stream_context_create() - Create a streams context
file_get_contents
28-Oct-2009 01:00
09-Jun-2009 09:35
In my dev environment with a relatively low-speed drive (standard SATA 7200RPM) reading a 25MB zip file in 10 times...
<?php
$data = `cat /tmp/test.zip`;
// 1.05 seconds
$fh = fopen('/tmp/test.zip', 'r');
$data = fread($fh, filesize('/tmp/test.zip'));
fclose($fh);
// 1.31 seconds
$data = file_get_contents('/tmp/test.zip');
// 1.33 seconds
?>
However, on a 21k text file running 100 iterations...
<?php
$data = `cat /tmp/test.txt`;
// 1.98 seconds
$fh = fopen('/tmp/test.txt', 'r');
$data = fread($fh, filesize('/tmp/test.txt'));
fclose($fh);
// 0.00082 seconds
$data = file_get_contents('/tmp/test.txt');
// 0.0069 seconds
?>
Despite the comment about file_get_contents being faster do to memory mapping, file_get_contents is slowest in both of the above examples. If you need the best performance out of your production box, you might want to throw together a script to check out which method is fastest for what size files on that particular machine, then optimize your code to check the file size and use the appropriate function for it.
10-Aug-2008 09:34
A UTF-8 issue I've encountered is that of reading a URL with a non-UTF-8 encoding that is later displayed improperly since file_get_contents() related to it as UTF-8. This small function should show you how to address this issue:
<?php
function file_get_contents_utf8($fn) {
$content = file_get_contents($fn);
return mb_convert_encoding($content, 'UTF-8',
mb_detect_encoding($content, 'UTF-8, ISO-8859-1', true));
}
?>
07-Aug-2008 12:34
if $filename has a relative path file_get_contents returns the uninterpreted sourcecode of the php-file with all comments etc.
I don't know whether this is a bug or intented or caused by server-configuration.
I think this behaviour should be included in the description of the function.
05-Aug-2008 11:13
I recently upgraded my server to Slackware 12.0.
After this, a program of mine stopped working: the call to file_get_contents (to an URL served by a custom HTTP server) was returning false without generating any error!
After some investigations I saw this: my custom HTTP server closes the connection at the end of the content. This (without the header "Connection: close") seems to cause the problem I described.
To solve the problem I simply added that header to the answer of my custom HTTP server.
19-Jul-2008 12:17
if( false == ($str=file_get_contents( '../relative_path/test.txt' )))
echo "Could not read file.";
else
echo "File contents: $str";
# Note: if the file cannot be opened then file_get_contents will attempt to warn the following:
# Warning: file_get_contents(filename): failed to open stream
http://www.codesplunk.com/nr/questions/php1.html
15-Apr-2008 09:38
Setting the timeout properly without messing with ini values:
<?php
$ctx = stream_context_create(array(
'http' => array(
'timeout' => 1
)
)
);
file_get_contents("http://example.com/", 0, $ctx);
?>
02-Apr-2008 09:12
This is a nice and simple substitute to get_file_contents() using curl, it returns FALSE if $contents is empty.
<?php
function curl_get_file_contents($URL)
{
$c = curl_init();
curl_setopt($c, CURLOPT_RETURNTRANSFER, 1);
curl_setopt($c, CURLOPT_URL, $URL);
$contents = curl_exec($c);
curl_close($c);
if ($contents) return $contents;
else return FALSE;
}
?>
Hope this help, if there is something wrong or something you don't understand let me know :)
29-Jan-2008 07:29
<?PHP
//PHP 4.2.x Compatibility function
if (!function_exists('file_get_contents')) {
function file_get_contents($filename, $incpath = false, $resource_context = null)
{
if (false === $fh = fopen($filename, 'rb', $incpath)) {
trigger_error('file_get_contents() failed to open stream: No such file or directory', E_USER_WARNING);
return false;
}
clearstatcache();
if ($fsize = @filesize($filename)) {
$data = fread($fh, $fsize);
} else {
$data = '';
while (!feof($fh)) {
$data .= fread($fh, 8192);
}
}
fclose($fh);
return $data;
}
}
?>
15-Jan-2008 11:58
I decided to make a similar function to this, called file_post_contents, it uses POST instead of GET to call, kinda handy...
<?php
function file_post_contents($url,$headers=false) {
$url = parse_url($url);
if (!isset($url['port'])) {
if ($url['scheme'] == 'http') { $url['port']=80; }
elseif ($url['scheme'] == 'https') { $url['port']=443; }
}
$url['query']=isset($url['query'])?$url['query']:'';
$url['protocol']=$url['scheme'].'://';
$eol="\r\n";
$headers = "POST ".$url['protocol'].$url['host'].$url['path']." HTTP/1.0".$eol.
"Host: ".$url['host'].$eol.
"Referer: ".$url['protocol'].$url['host'].$url['path'].$eol.
"Content-Type: application/x-www-form-urlencoded".$eol.
"Content-Length: ".strlen($url['query']).$eol.
$eol.$url['query'];
$fp = fsockopen($url['host'], $url['port'], $errno, $errstr, 30);
if($fp) {
fputs($fp, $headers);
$result = '';
while(!feof($fp)) { $result .= fgets($fp, 128); }
fclose($fp);
if (!$headers) {
//removes headers
$pattern="/^.*\r\n\r\n/s";
$result=preg_replace($pattern,'',$result);
}
return $result;
}
}
?>
03-Dec-2007 04:56
Seems file looks for the file inside the current working (executing) directory before looking in the include path, even with the FILE_USE_INCLUDE_PATH flag specified.
Same behavior as include actually.
By the way I feel the doc is not entirely clear on the exact order of inclusion (see include). It seems to say the include_path is the first location to be searched, but I have come across at least one case where the directory containing the file including was actually the first to be searched.
Drat.
11-Jul-2007 09:38
If you're having problems with binary and hex data:
I had a problem when trying to read information from a ttf, which is primarily hex data. A binary-safe file read automatically replaces byte values with their corresponding ASCII characters, so I thought that I could use the binary string when I needed readable ASCII strings, and bin2hex() when I needed hex strings.
However, this became a problem when I tried to pass those ASCII strings into other functions (namely gd functions). var_dump showed that a 5-character string contained 10 characters, but they weren't visible. A binary-to-"normal" string conversion function didn't seem to exist and I didn't want to have to convert every single character in hex using chr().
I used unpack with "c*" as the format flag to see what was going on, and found that every other character was null data (ordinal 0). To solve it, I just did
str_replace(chr(0), "", $string);
which did the trick.
This took forever to figure out so I hope this helps people reading from hex data!
02-May-2007 04:26
you'll find the http response headers in: $http_response_header
;o)
17-Apr-2007 04:37
[Editors note: As of PHP 5.2.1 you can specify `timeout` context option and pass the context to file_get_contents()]
The only way I could get get_file_contents() to wait for a very slow http request was to set the socket timeout as follows.
ini_set('default_socket_timeout', 120);
$a = file_get_contents("http://abcxyz.com");
Other times like execution time and input time had no effect.
05-Dec-2006 08:52
Use the previous example if you want to request the server for a special part of the content, IF and only if the server accepts the method.
If you want a simple example to ask the server for all the content, but only save a portion of it, do it this way:
<?
$content=file_get_contents("http://www.google.com",FALSE,NULL,0,20);
echo $content;
?>
This will echo the 20 first bytes of the google.com source code.
04-Aug-2006 08:55
the bug #36857 was fixed.
http://bugs.php.net/36857
Now you may use this code,to fetch the partial content like this:
<?php
$context=array('http' => array ('header'=> 'Range: bytes=1024-', ),);
$xcontext = stream_context_create($context);
$str=file_get_contents("http://www.fcicq.net/wp/",FALSE,$xcontext);
?>
that's all.
15-Nov-2005 10:47
If, like me, you are on a Microsoft network with ISA server and require NTLM authentication, certain applications will not get out of the network. SETI@Home Classic and PHP are just 2 of them.
The workaround is fairly simple.
First you need to use an NTLM Authentication Proxy Server. There is one written in Python and is available from http://apserver.sourceforge.net/. You will need Python from http://www.python.org/.
Both sites include excellent documentation.
Python works a bit like PHP. Human readable code is handled without having to produce a compiled version. You DO have the opportunity of compiling the code (from a .py file to a .pyc file).
Once compiled, I installed this as a service (instsrv and srvany - parts of the Windows Resource Kit), so when the server is turned on (not logged in), the Python based NTLM Authentication Proxy Server is running.
Then, and here is the bit I'm really interested in, you need to tell PHP you intend to route http/ftp requests through the NTLM APS.
To do this, you use contexts.
Here is an example.
<?php
// Define a context for HTTP.
$aContext = array(
'http' => array(
'proxy' => 'tcp://127.0.0.1:8080', // This needs to be the server and the port of the NTLM Authentication Proxy Server.
'request_fulluri' => True,
),
);
$cxContext = stream_context_create($aContext);
// Now all file stream functions can use this context.
$sFile = file_get_contents("http://www.php.net", False, $cxContext);
echo $sFile;
?>
Hopefully this helps SOMEONE!!!
31-Jan-2005 07:23
This functionality is now implemented in the PEAR package PHP_Compat.
More information about using this function without upgrading your version of PHP can be found on the below link:
http://pear.php.net/package/PHP_Compat
