PHP 手册
上一页 |  | 下一页

# http_cache_last_modified

(PECL)

http_cache_last_modified -- Caching by last modification

## 说明

bool http_cache_last_modified ( [int timestamp_or_expires] )

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 omitted, 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 设定 http.log.cache is set and the cache attempt was successful.

> 注意: This function may be used in conjunction with http_send_data(), http_send_file() 和 http_send_stream().

## 参数

`timestamp_or_expires`

  Unix timestamp

## 返回值

Returns `FALSE` or exits on success with `304 Not Modified` if the entity is cached. See the INI 设定 http.force_exit for what "exits" means.

## 范例

例 1. A http_cache_last_modified() example

Caching for 5 seconds.

`<?php http_cache_last_modified(-5); printf("%s\n", http_date()); ?>`

## 参见

http_cache_etag()
the HttpResponse class if you are using PHP-5.1 and above

上一页 | 起始页 | 下一页
http_cache_etag | 上一级 | http_chunked_decode