HTTP_CACHE_LAST_MODIFIED(3) 1 HTTP_CACHE_LAST_MODIFIED(3)
http_cache_last_modified - Caching by last modification
SYNOPSIS
bool http_cache_last_modified ([int $timestamp_or_expires])
DESCRIPTION
Attempts to cache the sent entity by its last modification date.
If the supplied argument is greater than 0, it is handled as timestamp and will be sent as date of last modification. If it is 0 or omit-
ted, the current time will be sent as Last-Modified date. If it's negative, it is handled as expiration time in seconds, which means that
if the requested last modification date is not between the calculated timespan, the Last-Modified header is updated and the actual body
will be sent.
A log entry will be written to the cache log if the INI settinghttp.log.cache is set and the cache attempt was successful.
Note
This function may be used in conjunction with http_send_data(3), http_send_file(3) and http_send_stream(3).
PARAMETERS
o $timestamp_or_expires
- Unix timestamp
RETURN VALUES
Returns FALSE or exits on success with 304 Not Modified if the entity is cached. See the INI settinghttp.force_exit for what "exits"
means.
EXAMPLES
Example #1
A http_cache_last_modified(3) example
Caching for 5 seconds.
<?php
http_cache_last_modified(-5);
printf("%s
", http_date());
?>
SEE ALSO
http_cache_etag(3), the HttpResponse class if you are using PHP 5.1.0 and above.
PHP Documentation Group HTTP_CACHE_LAST_MODIFIED(3)