No cache version.
Caching disabled. Default setting for this page:enabled (code LNG204)If the display is too slow, you can disable the user mode to view the cached version.
headers_sent
(PHP 4, PHP 5, PHP 7)
headers_sent — Checks if or where headers have been sent
Description
&$file
[, int &$line
]] ) : boolChecks if or where headers have been sent.
You can't add any more header lines using the header() function once the header block has already been sent. Using this function you can at least prevent getting HTTP header related error messages. Another option is to use Output Buffering.
Parameters
-
file
-
If the optional
file
andline
parameters are set, headers_sent() will put the PHP source file name and line number where output started in thefile
andline
variables. -
line
-
The line number where the output started.
Return Values
headers_sent() will return FALSE
if no HTTP headers
have already been sent or TRUE
otherwise.
Examples
Example #1 Examples using headers_sent()
<?php
// If no headers are sent, send one
if (!headers_sent()) {
header('Location: http://www.example.com/');
exit;
}
// An example using the optional file and line parameters
// Note that $filename and $linenum are passed in for later use.
// Do not assign them values beforehand.
if (!headers_sent($filename, $linenum)) {
header('Location: http://www.example.com/');
exit;
// You would most likely trigger an error here.
} else {
echo "Headers already sent in $filename on line $linenum\n" .
"Cannot redirect, for now please click this <a " .
"href=\"http://www.example.com\">link</a> instead\n";
exit;
}
?>
See Also
- ob_start() - Turn on output buffering
- trigger_error() - Generates a user-level error/warning/notice message
- headers_list() - Returns a list of response headers sent (or ready to send)
- header() - Send a raw HTTP header for a more detailed discussion of the matters involved.
Can not display this page of the Infobrol website
Type of error (18-01)
Unknown format specifier "&"Please try again in a few minutes…
Steph