Checking size of remote image

ripman

Hello,

I have trouble with checking the size of an image which doesn't return content-lenght in it's header.

Have anyone got any idea how to do it without downloading the whole file and checking it locally ?

regards,
Marcin

bretticus

without content-length and not downloading it, how else could you do it??? Is this being done via HTTP. I mean, will a browser even accept it without content-length?

I'm sure I'm speculating in all the wrong directions. Can you give some more information?

Weedpacket

Well, no; if the client won't tell the server what the file's size is, the server has to get the file in order to look and see how large it is.

ripman

http://img.allegro.pl/photos/oryginal/30/3094/309454/30945462

returns :

HTTP/1.0 200 OK
Date: Tue, 21 Sep 2004 18:51:19 GMT
Server: Apache/1.3.31 (Debian GNU/Linux) AuthMySQL/4.3.3 PHP/4.3.4
Cache-Control: max-age=1209600
Expires: Tue, 05 Oct 2004 18:51:19 GMT
Last-Modified: Wed, 08 Sep 2004 18:17:02 GMT
ETag: "770244-bbc7-413f4c9e"
Content-Type: image/jpeg
Age: 47290
X-Cache: HIT from s210.allegro.pl
X-Cache-Lookup: HIT from s210.allegro.pl:80
X-Cache: MISS from s214.allegro.pl
X-Cache-Lookup: MISS from s214.allegro.pl:80
Connection: close

any ideas ?

Weedpacket

Conversely; if the server won't tell the client what the file's size is, the client has to download the file in order to look and see how large it is.

Installer

You could use "fsockopen()", then "fgetc()" to read the bytes one at a time. For a gif image the width is stored in byte offset 6 and 7, and the height in bytes 8 and 9 (little-endian). For jpeg, even though there are several variations of the format, I think they all contain two-byte start-of-frame markers throughout the file, with the height in the 5th and 6th bytes after, and the width in the 7th and 8th bytes (big-endian).

Edit: code removed. I screwed it up before posting it. Besides, you want size, not dimensions, I guess. Sorry. Check out verran's user comment on the " fosockopen()" page.