Nginx an If statement Gazheng the expression implements string truncation _nginx

Before we tell you this question, let's look at a nginx configuration. We used the set-misc-nginx-module.

Copy Code code as follows:

location/test/{
Default_type text/html;
SET_MD5 $hash "secret" $remote _addr;
Echo $hash;
}

So the output comes to the content that might be the following

Copy Code code as follows:

202cb962ac59075b964b07152d234b70

But what if we want to intercept a few characters?
First of all, you must think of the use of modules to achieve, but only this? Is there a more convenient way?

Some.
We can use the IF + regular expression skillfully to implement this small requirement:

Copy Code code as follows:

location/test/{
Default_type text/html;
SET_MD5 $hash "secret" $remote _addr;
if ($hash ~ ^[\w][\w][\w][\w][\w][\w][\w][\w] ([\w][\w][\w][\w][\w][\w][\w][\w]) {
Set $hash $;
}
Echo $hash;
}

Access to/test/output is:

Copy Code code as follows:

ac59075b