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nocache_headers()

Set the headers to prevent caching for the different browsers.

Description

Different browsers support different nocache headers, so several headers must be sent so that all of them get the point that no caching should occur.

See also

Source

File: wp-includes/functions.php

function nocache_headers() {
	$headers = wp_get_nocache_headers();

	unset( $headers['Last-Modified'] );

	// In PHP 5.3+, make sure we are not sending a Last-Modified header.
	if ( function_exists( 'header_remove' ) ) {
		@header_remove( 'Last-Modified' );
	} else {
		// In PHP 5.2, send an empty Last-Modified header, but only as a
		// last resort to override a header already sent. #WP23021
		foreach ( headers_list() as $header ) {
			if ( 0 === stripos( $header, 'Last-Modified' ) ) {
				$headers['Last-Modified'] = '';
				break;
			}
		}
	}

	foreach ( $headers as $name => $field_value ) {
		@header( "{$name}: {$field_value}" );
	}
}

Changelog

Version Description
2.0.0 Introduced.

© 2003–2019 WordPress Foundation
Licensed under the GNU GPLv2+ License.
https://developer.wordpress.org/reference/functions/nocache_headers