# An unexpected newline appears when use memc and echo\_location\_async, how to delete the newline? **URL:** \ **Category:** NGINX\ **Created:** [June 15, 2012, 3:50pm UTC](https://www.ruby-forum.com/t/an-unexpected-newline-appears-when-use-memc-and-echo-location-async-how-to-delete-the-newline/220661 "2012-06-15T15:50:41Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![aris](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/a/258eb7/32.png) [@aris](https://www.ruby-forum.com/u/aris)\ **Post date:** [June 15, 2012, 3:50pm UTC](https://www.ruby-forum.com/t/an-unexpected-newline-appears-when-use-memc-and-echo-location-async-how-to-delete-the-newline/220661/1 "2012-06-15T15:50:41Z")
I use the agenzh’s two modules > **[Memc | NGINX](https://www.nginx.com/resources/wiki/modules/memc/)** > > The Memc module is an An extended version of the standard memcached module that supports set, add, delete, and many more memcached commands. > **[HTTP Echo Module | NGINX](https://www.nginx.com/resources/wiki/modules/echo/)** > > The HTTP Echo module brings "echo", "sleep", "time", "exec" and more shell-style goodies to your NGINX configuration files. \*\* _nginx configuration:_ ``` location ~ "^/property/([0-9]+)" { charset utf-8; default_type 'text/javascript'; echo -n "$arg_callback({\"property_$1\":\""; echo_location_async /statistic/operator ``` “cmd=incr&key=property\_$1&value=1”; echo -n “")”; } ``` # GET /statistic/operator?cmd=incr&key=property_23214&value=2 # GET /statistic/operator?cmd=decr&key=property_23214&value=1 location /statistic/operator { internal; set $memc_cmd $arg_cmd; set $memc_key $arg_key; set $memc_value $arg_value; memc_pass statistics_server_pool; memc_cmds_allowed incr decr set get delete add; add_header X-Memc-Flags 'Statistic Crement'; } ``` _Request URL:_ [http://domain.net/property/23458?hi=231231&callback=himycallback201203455](http://domain.net/property/23458?hi=231231&callback=himycallback201203455) _The Unexpect incorrect Output: (Current Configuration)_ himycallback201203455({“property\_23458”:24 }) The new line after 24 is unexpected. and how can l delete the new line ? _I expected the correct Output: ( how to configuration the nginx ? )_ himycallback201203455({“property\_23458”:24}) ---
**Author:** ![Xiangong\_Y](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/94ad74/32.png) [@Xiangong\_Y](https://www.ruby-forum.com/u/Xiangong_Y)\ **Post date:** [June 16, 2012, 4:08am UTC](https://www.ruby-forum.com/t/an-unexpected-newline-appears-when-use-memc-and-echo-location-async-how-to-delete-the-newline/220661/2 "2012-06-16T04:08:36Z")
Hello! On Fri, Jun 15, 2012 at 9:49 PM, Xiangong Y. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > The Unexpect incorrect Output: (Current Configuration) > > himycallback201203455({“property\_23458”:24 > }) > The new line after 24 is unexpected. and how can l delete the new line ? Please ensure that the value you inserted into memcached does not have the trailing new line by using telnet to access your memcached, like this: ``` $ telnet get property_23458 ``` If the original value in your memcached server contains a trailing newline, then neither ngx\_memc nor ngx\_echo will automatically strip it for you. Also, to do JSONP padding in nginx, you’re recommended to use the ngx\_xss module which is more efficient and more secure: ``` https://github.com/agentzh/xss-nginx-module ``` Best regards, -agentzh ---
**Author:** ![Xiangong\_Y](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/94ad74/32.png) [@Xiangong\_Y](https://www.ruby-forum.com/u/Xiangong_Y)\ **Post date:** [June 16, 2012, 4:34am UTC](https://www.ruby-forum.com/t/an-unexpected-newline-appears-when-use-memc-and-echo-location-async-how-to-delete-the-newline/220661/3 "2012-06-16T04:34:55Z")
Hello! On Sat, Jun 16, 2012 at 10:08 AM, agentzh [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > Please ensure that the value you inserted into memcached does not have > the trailing new line by using telnet to access your memcached, like > this: Sorry, I was reading too fast. For the memcached commands other than “get”, ngx\_memc will return the raw memcached responses, and in your case, for the “incr” command, the response is ended by a CR LF sequence. If it bothers you, then you’re recommended to use ngx\_lua with lua-resty-memcached instead, for example: # the following line is not required if the ngx\_openresty bundle is used. lua\_package\_path “/path/to/lua-resty-memcached/lib/?.lua;;”; server { listen 8080; ``` location ~ "^/property/([0-9]+)" { charset utf-8; default_type 'application/json'; xss_callback_arg callback; xss_get on; content_by_lua ' local memcached = require "resty.memcached" local memc = memcached:new() memc:set_timeout(500) -- 500 ms local ok, err = memc:connect("127.0.0.1", 11211) if not ok then ngx.log(ngx.ERR, "failed to connect to memcached: ", ``` err) return ngx.exit(500) end ``` local key = "property_" .. ngx.var[1] local newval, err = memc:incr(key, 1) if not newval then ngx.log(ngx.ERR, "failed to incr the key in memcached: ``` ", err) return ngx.exit(500) end ``` -- the connection pool capacity is set to 1024 connections memc:set_keepalive(0, 1024) ngx.print([[{"]], key, [[":"]], newval, [["}]]) '; } ``` } Then we can get: ``` $ curl -i ``` localhost:8080/property/23458?callback=himycallback201203455 HTTP/1.1 200 OK Server: nginx/1.0.15 Date: Sat, 16 Jun 2012 02:31:57 GMT Content-Type: application/x-javascript; charset=utf-8 Transfer-Encoding: chunked Connection: keep-alive ``` himycallback201203455({"property_23458":"30"}); ``` And when the callback argument is not given: ``` $ curl -i localhost:8080/property/23458 HTTP/1.1 200 OK Server: nginx/1.0.15 Date: Sat, 16 Jun 2012 02:32:51 GMT Content-Type: application/json Transfer-Encoding: chunked Connection: keep-alive {"property_23458":"31"} ``` The example above utilizes the following components: ``` http://wiki.nginx.org/HttpLuaModule https://github.com/agentzh/lua-resty-memcached https://github.com/agentzh/xss-nginx-module ``` If you’re too lazy to download and install all these dependencies, you can try out the ngx\_openresty bundle instead: ``` http://openresty.org/#Download ``` Best regards, -agentzh ---
**Author:** ![Xiangong\_Y](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/x/94ad74/32.png) [@Xiangong\_Y](https://www.ruby-forum.com/u/Xiangong_Y)\ **Post date:** [June 16, 2012, 5:36am UTC](https://www.ruby-forum.com/t/an-unexpected-newline-appears-when-use-memc-and-echo-location-async-how-to-delete-the-newline/220661/4 "2012-06-16T05:36:52Z")
Thank you very much, agentzh! I’ll immediately try the xss-nginx-module module in your guide. 2012/6/16 agentzh [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)