Php что такое ошибка 404

header($_SERVER["SERVER_PROTOCOL"]." 404 Not Found");

instead of

header("HTTP/1.1 404 Not Found");

I had big troubles with an Apache/2.0.59 (Unix) answering in HTTP/1.0 while I (accidentially) added a "HTTP/1.1 200 Ok" - Header.

Most of the pages were displayed correct, but on some of them apache added weird content to it:

A 4-digits HexCode on top of the page (before any output of my php script), seems to be some kind of checksum, because it changes from page to page and browser to browser. (same code for same page and browser)

"0" at the bottom of the page (after the complete output of my php script)

It took me quite a while to find out about the wrong protocol in the HTTP-header.

If you want to redirect an user and tell him he will be redirected, e. g. "You will be redirected in about 5 secs. If not, click here." you cannot use header( 'Location: ...' ) as you can't sent any output before the headers are sent.

So, either you have to use the HTML meta refresh thingy or you use the following:

<?php

  header( "refresh:5;url=wherever.php" );

  echo 'You'll be redirected in about 5 secs. If not, click <a href="wherever.php">here</a>.';

?>



Hth someone

<?php
// 301 Moved Permanently
header("Location: /foo.php",TRUE,301);// 302 Found
header("Location: /foo.php",TRUE,302);
header("Location: /foo.php");// 303 See Other
header("Location: /foo.php",TRUE,303);// 307 Temporary Redirect
header("Location: /foo.php",TRUE,307);
?>

The HTTP status code changes the way browsers and robots handle redirects, so if you are using header(Location:) it's a good idea to set the status code at the same time.  Browsers typically re-request a 307 page every time, cache a 302 page for the session, and cache a 301 page for longer, or even indefinitely.  Search engines typically transfer "page rank" to the new location for 301 redirects, but not for 302, 303 or 307. If the status code is not specified, header('Location:') defaults to 302.

Here's how:

<?php// Test image.
    $fn = '/test/foo.png';// Getting headers sent by the client.
    $headers = apache_request_headers(); // Checking if the client is validating his cache and if it is current.
    if (isset($headers['If-Modified-Since']) && (strtotime($headers['If-Modified-Since']) == filemtime($fn))) {
        // Client's cache IS current, so we just respond '304 Not Modified'.
        header('Last-Modified: '.gmdate('D, d M Y H:i:s', filemtime($fn)).' GMT', true, 304);
    } else {
        // Image not cached or cache outdated, we respond '200 OK' and output the image.
        header('Last-Modified: '.gmdate('D, d M Y H:i:s', filemtime($fn)).' GMT', true, 200);
        header('Content-Length: '.filesize($fn));
        header('Content-Type: image/png');
        print file_get_contents($fn);
    }?>

That way foo.png will be properly cached by the client and you'll save bandwith. :)

So instead of typing:

<?php
  header("Content-Disposition: attachment; filename=" . basename($filename));
?>

you should type:

<?php
  header("Content-Disposition: attachment; filename="" . basename($filename) . """);
?>

If you don't do this then when the user clicks on the link for a file named "Example file with spaces.txt", then Firefox's Save As dialog box will give it the name "Example", and it will have no extension.

See the page called "Filenames_with_spaces_are_truncated_upon_download" at
http://kb.mozillazine.org/ for more information. (Sorry, the site won't let me post such a long link...)

Content-Disposition: attachment;
                          filename*= UTF-8''%e2%82%ac%20rates

for backward compatibility, what should be sent is:

Content-Disposition: attachment;
                          filename="EURO rates";
                          filename*=utf-8''%e2%82%ac%20rates

As a result, we should use

<?php
$filename = '中文文件名.exe';   // a filename in Chinese characters$contentDispositionField = 'Content-Disposition: attachment; '
    . sprintf('filename="%s"; ', rawurlencode($filename))
    . sprintf("filename*=utf-8''%s", rawurlencode($filename));header('Content-Type: application/octet-stream');header($contentDispositionField);readfile('file_to_download.exe');
?>

I have tested the code in IE6-10, firefox and Chrome.

If you use something like "header('text/javascript');" to set the MIME type for PHP response text (such as for echoed or Included data), you will get an undiagnosed failure.

The proper MIME-setting function is "header('Content-type: text/javascript');".

<?php

$last_modified_time = filemtime($file);

$etag = md5_file($file);
header("Last-Modified: ".gmdate("D, d M Y H:i:s", $last_modified_time)." GMT");

header("Etag: $etag");

if (@

strtotime($_SERVER['HTTP_IF_MODIFIED_SINCE']) == $last_modified_time ||

    trim($_SERVER['HTTP_IF_NONE_MATCH']) == $etag) {

    header("HTTP/1.1 304 Not Modified");

    exit;

}

?>

// In other words, use 301 if permanent, 302 if temporary, and 303 if a results page from a submitted form.
// Maybe use 307 if a form processing script has moved.

Cache-control:no-store
Cache-control:no-cache

See: http://support.microsoft.com/kb/323308

Workaround: do not send those headers.

Also, be aware that IE versions 5, 6, 7, and 8 double-compress already-compressed files and do not reverse the process correctly, so ZIP files and similar are corrupted on download.

Workaround: disable compression (beyond text/html) for these particular versions of IE, e.g., using Apache's "BrowserMatch" directive. The following example disables compression in all versions of IE:

BrowserMatch ".*MSIE.*" gzip-only-text/html

«An obsolete version of the HTTP 1.1 specifications (IETF RFC 2616) required a complete absolute URI for redirection.[2] The IETF HTTP working group found that the most popular web browsers tolerate the passing of a relative URL[3] and, consequently, the updated HTTP 1.1 specifications (IETF RFC 7231) relaxed the original constraint, allowing the use of relative URLs in Location headers.»

session_cache_limiter('');

...after you set your custom cache headers. It will tell the PHP session code to not do any cache header changes of its own.

This redirects to 2.html since the second header replaces the first.

<?php
header("location: 1.html");
header("location: 2.html"); //replaces 1.html
?>

This redirects to 1.html since the header is sent as soon as the echo happens. You also won't see any "headers already sent" errors because the browser follows the redirect before it can display the error.

<?php
header("location: 1.html");
echo "send data";
header("location: 2.html"); //1.html already sent
?>

Wrapping the previous example in an output buffer actually changes the behavior of the script! This is because headers aren't sent until the output buffer is flushed.

<?php
ob_start();
header("location: 1.html");
echo "send data";
header("location: 2.html"); //replaces 1.html
ob_end_flush(); //now the headers are sent
?>

<?php

    header("Location: URL");

    exit();

?>



is recommended if you want to be sure the session is updated before proceeding to the redirection.

We encountered a situation where the script accessed by the redirection wasn't loading the session correctly because the precedent script hadn't the time to update it (we used a database handler).

JP.

Content-Transfer-Encoding specifies the encoding used to transfer the data within the HTTP protocol, like raw binary or base64. (binary is more compact than base64. base64 having 33% overhead).
Eg Use:- header('Content-Transfer-Encoding: binary');

Content-Encoding is used to apply things like gzip compression to the content/data.
Eg Use:- header('Content-Encoding: gzip');

    header_remove();
    header("Cache-Control: no-store, no-cache, must-revalidate, max-age=0");
    header("Cache-Control: post-check=0, pre-check=0", false);
    header("Pragma: no-cache");
    // ... and then try redirecting
    // 201 = The request has been fulfilled, resulting in the creation of a new resource however it's still not loading
    // 302 "moved temporarily" does seems to load it!
    header("location:$dst", FALSE, 302); // redirect to the file now we have it

<?php
header("Content-Disposition: attachment; filename=" . urlencode($file));   
header("Content-Type: application/force-download");
header("Content-Type: application/octet-stream");
header("Content-Type: application/download");
header("Content-Description: File Transfer");            
header("Content-Length: " . filesize($file));
flush(); // this doesn't really matter.$fp = fopen($file, "r");
while (!feof($fp))
{
    echo fread($fp, 65536);
    flush(); // this is essential for large downloads
} 
fclose($fp);
?>

header

('Location: http://www.example.com/');
die();?>
'CAUSE all die function does is to stop the script ,there is no other place for interpretation and the scope you choose to break the action of your script is quickly DONE!!!

there are many situations  with others examples and the right choose for small parts of your scrips that make differences when you write your php framework at well!

Thanks Rasmus Lerdorf and his team to wrap off parts of unusual php functionality ,php 7 roolez!!!!!

PHP, by default, always returns the following header:

"Content-Type: text/html"

Which your entire header response will look like

HTTP/1.1 200 OK
Server: Apache/2.2.11 (Unix)
X-Powered-By: PHP/5.2.8
Date: Fri, 16 Oct 2009 23:05:07 GMT
Content-Type: text/html; charset=UTF-8
Connection: close

If you call the header name with no value like so...

<?php

    header

( 'Content-Type:' );?>

Your headers now look like this:

HTTP/1.1 200 OK
Server: Apache/2.2.11 (Unix)
X-Powered-By: PHP/5.2.8
Date: Fri, 16 Oct 2009 23:05:07 GMT
Connection: close

Warning: Cannot modify header information - headers already sent by (output started at C:wwwinfo.php:1) in C:wwwinfo.php on line 1

  Take a look at this code, which replicates the normal download of a Javascript:

<?php
if(strstr($_SERVER["HTTP_USER_AGENT"],"MSIE")==false) {
  header("Content-type: text/javascript");
  header("Content-Disposition: inline; filename="download.js"");
  header("Content-Length: ".filesize("my-file.js"));
} else {
  header("Content-type: application/force-download");
  header("Content-Disposition: attachment; filename="download.js"");
  header("Content-Length: ".filesize("my-file.js"));
}
header("Expires: Fri, 01 Jan 2010 05:00:00 GMT");
if(strstr($_SERVER["HTTP_USER_AGENT"],"MSIE")==false) {
  header("Cache-Control: no-cache");
  header("Pragma: no-cache");
}
include("my-file.js");
?>

Now let me explain:

  I start out by checking for IE, then if not IE, I set Content-type (case-sensitive) to JS and set Content-Disposition (every header is case-sensitive from now on) to inline, because most browsers outside of IE like to display JS inline. (User may change settings). The Content-Length header is required by some browsers to activate download box. Then, if it is IE, the "application/force-download" Content-type is sometimes required to show the download box. Use this if you don't want your PDF to display in the browser (in IE). I use it here to make sure the box opens. Anyway, I set the Content-Disposition to attachment because I already know that the box will appear. Then I have the Content-Length again.

  Now, here's my big point. I have the Cache-Control and Pragma headers sent only if not IE. THESE HEADERS WILL PREVENT DOWNLOAD ON IE!!! Only use the Expires header, after all, it will require the file to be downloaded again the next time. This is not a bug! IE stores downloads in the Temporary Internet Files folder until the download is complete. I know this because once I downloaded a huge file to My Documents, but the Download Dialog box put it in the Temp folder and moved it at the end. Just think about it. If IE requires the file to be downloaded to the Temp folder, setting the Cache-Control and Pragma headers will cause an error!

I hope this saves someone some time!
~Cody G.

After decompressing the file, I ran into the problem, that the download dialog would always pop up, even when I told the dialog to 'Always perform this operation with this file type'.

As I found out, the problem was in the header directive 'Content-Disposition', namely the 'attachment' directive.

If you want your browser to simulate a plain link to a file, either change 'attachment' to 'inline' or omit it alltogether and you'll be fine.

This took me a while to figure out and I hope it will help someone else out there, who runs into the same problem.

1. All used headers have first letters uppercase, so you MUST follow this. For example:

Location, not location

Content-Type, not content-type, nor CONTENT-TYPE

2. Then there MUST be colon and space, like

good: header("Content-Type: text/plain");

wrong: header("Content-Type:text/plain");

3. Location header MUST be absolute uri with scheme, domain, port, path, etc.

good: header("Location: http://www.example.com/something.php?a=1");

4. Relative URIs are NOT allowed

wrong:  Location: /something.php?a=1

wrong:  Location: ?a=1

It will make proxy server and http clients happier.

     header("status: 204");  (or the other call)

     header("HTTP/1.0 204 No Response");

<?PHP

header( 'Expires: Sat, 26 Jul 1997 05:00:00 GMT' );

header( 'Last-Modified: ' . gmdate( 'D, d M Y H:i:s' ) . ' GMT' );

header( 'Cache-Control: no-store, no-cache, must-revalidate' );

header( 'Cache-Control: post-check=0, pre-check=0', false );

header( 'Pragma: no-cache' );
?>

On another note: Safari can display CMYK images (at least the OS X version, because it uses the services of QuickTime)

// INSTEAD USE THIS ->
header("Location: #wahtever"); // -> will work forever !

It will also disregard any expressly set "Content-Type: " and forces:

"Content-Type: text/html; charset=UTF-8"

The HTTP RFCs don't call for such a drastic action. They simply state that a redirect content SHOULD include a link to the destination page (in which case ANY HTML compatible content type would do). But PHP even overrides a perfectly standards-compliant
"Content-Type: application/xhtml+xml"!

//This line causes the error
        7
header('Location : index.php&controller=produit&action=index');

// While It must be written without the space
header('Location: index.php&controller=produit&action=index');