是否可以读取大型网页的最后几行（或1000个字符）？(is it possible to read the last few lines (or 1000 characters say) of a l

是否可以读取大型网页的最后几行（或1000个字符）？(is it possible to read the last few lines (or 1000 characters say) of a large web page?)

我们需要每5分钟轮询一次网页，并且网页正在变得相当大。 网页是一个目录列表，我们需要最后一行（获取文件名）。 得到最后一行的最佳方式是什么？

（如果这是一个本地文件，我可以在文件末尾找一个相对位置并读取）。

We need to poll a web page every 5 minutes and the web page is growing rather large. The web page is a directory listing and we need the last line (to get a file name). What is the best way to get just this last line?

(If this was a local file I could position back a little relative to the end of file and read).

最满意答案

HTTP 1.1确实支持一组标题来只请求特定范围的字节，包括仅支持文件的最后n个字节（使用“后缀”格式）。 看到这里 。 例如，

Range: bytes=-1000

为最后的1000字节。 （当然，假设服务器支持Range标头。）

HTTP 1.1 does support a set of headers to request only a particular range of bytes, including support for just the last n bytes of a file (using the "suffix" format). See here. For instance,

Range: bytes=-1000

for the last 1000 bytes. (Assuming the server supports the Range header, of course.)