reqular expression in lua

ming.liu1123

Hi guys

There is another question about re in ngx content_by_lua

local request_uri, n = ngx.re.gsub(original_request_uri, "(jsonp_)?callback=jsonp\\d+", "") or

local request_uri, n = ngx.re.gsub(original_request_uri, "(jsonp_)?callback=jsonp%d+", "")

seem not work for

http://localhost:80/search?id=0267&jsonp_callback=jsonp111

http://localhost:80/search?id=0267&callback=jsonp111

Any suggestions?

Thanks

agentzh

Hello!

On Wed, Jun 13, 2012 at 10:00 AM, james_openresty
<ming....@gmail.com> wrote:
> There is another question about re in ngx content_by_lua
> local request_uri, n = ngx.re.gsub(original_request_uri,
> "(jsonp_)?callback=jsonp\\d+", "")  or
> local request_uri, n = ngx.re.gsub(original_request_uri,
> "(jsonp_)?callback=jsonp%d+", "")
> seem not work for
> http://localhost:80/search?id=0267&jsonp_callback=jsonp111
> http://localhost:80/search?id=0267&callback=jsonp111
> Any suggestions?
>

I think you're experiencing issues with regex escaping while inlining
Lua code right into nginx.conf (see
http://wiki.nginx.org/HttpLuaModule#Special_PCRE_Sequences ). It
requires special attention for \ escaping.

Try the following example instead:

    location = /search {
        content_by_lua '
            local uri = ngx.var.request_uri
            local new_uri, n = ngx.re.gsub(uri,
                 [[(?:jsonp_)?callback=jsonp\\d+]], "")
            ngx.say(new_uri)
        ';
    }

Then GET /search?id=0267&jsonp_callback=jsonp111 gives

    /search?id=0267&

which should be what you would expect :)

Regards,
-agentzh

ming.liu1123

Thanks agentzh!

I changed to use lua string.gsub

I will try this later

On Wednesday, June 13, 2012 10:55:32 AM UTC+8, agentzh wrote:

Hello!

On Wed, Jun 13, 2012 at 10:00 AM, james_openresty
wrote:
> There is another question about re in ngx content_by_lua
> local request_uri, n = ngx.re.gsub(original_request_uri,
> "(jsonp_)?callback=jsonp\\d+", "") or
> local request_uri, n = ngx.re.gsub(original_request_uri,
> "(jsonp_)?callback=jsonp%d+", "")
> seem not work for
> http://localhost:80/search?id=0267&jsonp_callback=jsonp111
> http://localhost:80/search?id=0267&callback=jsonp111
> Any suggestions?
>

I think you're experiencing issues with regex escaping while inlining
Lua code right into nginx.conf (see
http://wiki.nginx.org/HttpLuaModule#Special_PCRE_Sequences ). It
requires special attention for \ escaping.

Try the following example instead:

location = /search {
content_by_lua '
local uri = ngx.var.request_uri
local new_uri, n = ngx.re.gsub(uri,
[[(?:jsonp_)?callback=jsonp\\d+]], "")
ngx.say(new_uri)
';
}

Then GET /search?id=0267&jsonp_callback=jsonp111 gives

/search?id=0267&

which should be what you would expect :)

Regards,
-agentzh