What means?

Question

There is a line in the Apache configuration file to avoid gzip compression for images:

SetEnvIfNoCase Request_URI \.(?:gif|jpe?g|png)$ no-gzip dont-vary

I do not believe that a file name exists .gif, for example myfile.*:gif.

So what does it mean ?:?

Answer 1

This particular part (?:gif|jpe?g|png)is almost the same as (gif|jpe?g|png).

The difference here is that the first will not “capture” the group in parentheses. In other words, when viewing matches, the material in the first example will not be included as a special group.

, , " ". , "", . (?:stuff), , .

, , , :

"([^.]\.)(?:gif|png|tiff)"

. , .