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Contents 1 mod_curl (HTTP request API) 1.1 Installing 1.2 Application 1.3 CLI / API 1.4 Lua Usage

mod_curl (HTTP request API)

mod_curl allows one to make a http request and receive the response. Output can be plain text (headers optional) or a json object.

Installing

To use mod_curl:

Tell FreeSWITCH to compile in this module by editing modules.conf in /usr/src/freeswitch/trunk and uncomment:

#applications/mod_curl

Now go recompile FreeSWITCH.

make
make install

Tell FreeSWITCH to actually use the curl module when running by adding the module to modules.conf.xml in /usr/local/freeswitch/conf/autoload_configs:

<load module="mod_curl"/>

There is no separate config file for mod_curl.

Now load up FreeSWITCH!

Application

The syntax is:

<action application="curl" data="url [headers|json] [get|head|post [url_encode_data]]"/>

The curl application sets the variables curl_response_data and curl_response_code. curl_response_data can also be headers/body or json if requested.

<action application="curl" data="http://www.google.com"/>
<action application="info"/>
<action application="curl" data="http://www.google.com headers"/>
<action application="info"/>
<action application="curl" data="http://www.google.com json"/>
<action application="info"/>

CLI / API

The CLI uses the api interface. The syntax is:

curl url [headers|json] [get|head|post [url_encode_data]]

From the commandline line issue:

curl http://www.google.com

This will return google's home page.

curl http://www.google.com/ headers

Will give you the headers followed by the body. And

curl http://www.google.com/ json

Will give you the headers and body in a structured json stream.

Send POST and GET request.

curl http://www.myhost.com/?get=myGetValue
curl http://www.myhost.com post post=myPostValue%20a%20space

Mix with headers or JSON.

curl http://www.myhost.com/?get=myGetValue json
curl http://www.myhost.com headers post post=myPostValue%20a%20space

Lua Usage

Note: it is good practice to check session:ready() before any long function calls such as a HTTP request so that your script stops running and releases its resources as soon as possible if the call is hung up.

This shows how to do a GET request:

session:execute("curl", "http://www.myhost.com/?name1=value1&name2=value2")
curl_response_code = session:getVariable("curl_response_code")
curl_response      = session:getVariable("curl_response_data")

This shows how to do a POST request:

session:execute("curl", "http://www.myhost.com/ post name1=value1&name2=value2")
curl_response_code = session:getVariable("curl_response_code")
curl_response      = session:getVariable("curl_response_data")

You can also use the API interface:

api = freeswitch.API();
get_response = api:execute("curl", "http://www.myhost.com/?name1=value1&name2=value2")
post_response = api:execute("curl", "http://www.myhost.com/ post name1=value1&name2=value2")

In all the above examples, the submitted values must be URL encoded.

Submit:
 first  = "a short value"
 second = "a slightly longer value"
as:
 first=a%20short%20value&second=a%20slightly%20longer%20value

This shows one method of encoding parameters to form a GET/POST request: (or use CGILua's urlcode)

function codificaParametros(paramsT)
	function escape (s)
	  s = string.gsub(
		s, 
		'([\r\n"#%%&+:;<=>?@^`{|}%\\%[%]%(%)$!~,/\'])', 
		function (c)
			return '%'..string.format("%X", string.byte(c))
		end
	)
	  s = string.gsub(s, "%s", "+")
	  return s
	end

	function encode (t)
	  local s = ""
	  for k , v in pairs(t) do
		s = s .. "&" .. escape(k) .. "=" .. escape(v)
	  end
	  return string.sub(s, 2)     -- remove first `&'
	end
	
	if type(paramsT) == 'table' then
		return encode(paramsT)
	else
		local tmp = Utils:commaText(paramsT, '&'); 
		local myParamsT = {};
		for k, v in pairs(tmp) do
			local pos = 0
			pos = string.find(v, '=')
			if not pos then return '' end
			myParamsT[string.sub(v, 1, pos-1 )] = string.sub(v, pos+1 )
		end
		return encode(myParamsT)
	end
end

 
 local paramsT  = {
    param1 = 'valor1',
    param2 = '\nh@la<>?'
 }
 local encode = codificaParametros (paramsT)
 session:answer()
 print (string.format("\n%s\n", encode));
--param1=valor1&param2=%Ah%40la%3C%3E%3F
 session:hangup();