Apache2: Change response headers
I'm running on my ubuntu 12.04 system apache2 and playing around with response headers. I want to change the behavior of http response headers, especially the Content-Length header. I've tried adding following lines in my apache2.conf in the IfModule mod_headers.c section:
Header set Static-Header "Static Content with nonsense"
Header set Content-Length "1338"
If I run curl -I localhost I get the expected header field Content-Length: 1338 (curl -I performs a HEAD request).
If I run curl -i the Content-Length is correctly calculated.
In RFC2616, section 9.4 is described that the HEAD request SHOULD be identical to the information sent in response to a GET request.
Can someone explain me this behavior?!
Apache2 always calculates the content-length from scratch when it actually does deliver content. You'll experience that same behavior if you change that header using PHP. This is necessary to make sure the Content-Length matches the length of the content that is sent after the server applied, for example, compression (if mod_deflate is active).
Because of this, in any request that sends content, your change to that header is nullified. But as Apache doesn't even look at the content in an head-request (only it's metadata), it does not calculate content-length. This is valid, as HEAD-requests don't have any body, so content-length is always zero.
Therefore, you should:
a) not modify the content-length header in the first place
b) not send one for HEAD requests
上一篇: 虚拟主机Apache2（Ubuntu 14.04）
下一篇: Apache2：更改响应标题