LSL HTTP server/examples

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< LSL HTTP server
Revision as of 17:41, 8 November 2009 by Opensource Obscure (talk | contribs) (Added a Grid URL Persister sample script + Web-based dynamic buildings reference)
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Utility Script

A script intended as a 'fill in the blank' exercise for very, very simple HTTP servers is here: Utility Script

Hello World!

Classic example, the smallest http_request script possible. <lsl> default { 

   state_entry()
   {
       llRequestURL();
   }

   http_request(key id, string method, string body)
   {
       if (method == URL_REQUEST_GRANTED)
       {
           llSay(0,"URL: " + body);
       }
       else if (method == "GET")
       {
           llHTTPResponse(id,200,"Hello World!");
       }
   }

} </lsl> A slightly more robust version: <lsl> default { 

   state_entry()
   {
       llRequestURL();
   }

   http_request(key id, string method, string body)
   {
       if (method == URL_REQUEST_GRANTED)
       {
           llSay(0,"URL: " + body);
       }
       else if (method == URL_REQUEST_DENIED)
       {
           llSay(0, "Something went wrong, no url. " + body);
       }
       else if (method == "GET")
       {
           llHTTPResponse(id,200,"Hello World!");
       }
       else
       {
           llHTTPResponse(id,405,"Unsupported Method");
       }
   }

} </lsl>

Echo World

"Echo World (Byrd Sciavo 04:19, 7 October 2009 (UTC))" is a slightly more useful "Hello World", demonstrating a basic server that echos back dynamic data fed. Echo World shows how http_request receives GET variables. To receive this "dynamic echo", append your cap url with a query string, such as https://sim3015.aditi.lindenlab.com:12043/cap/a7717681-2c04-e4ac-35e3-1f01c9861322/foo/bar?arg=gra <lsl> string url; default { 

   state_entry(){
       llRequestURL();
   }

   http_request(key id, string method, string body){    
       if (method == URL_REQUEST_GRANTED) {
           url=body;llOwnerSay(url);
       }else if(method=="GET"){
             if(llGetHTTPHeader(id,"x-query-string")=="") llHTTPResponse(id,200,"I ECHO when you append some GET variables to me, e.g., /?var=foo");
             else llHTTPResponse(id,200,llGetHTTPHeader(id,"x-query-string"));
       }        
   }

} </lsl>

Visitor List

A list of residents within sensor range of the server.
Notes:

  • This includes a method for handling multiple requests while waiting for asynchronous data requests to come back.

<lsl>integer scanning = FALSE;

list requests;

send_response(string body) { 

   integer j;
   for (j = 0; j < llGetListLength(requests); ++j)
   {
       llHTTPResponse(llList2Key(requests,j), 200, body);
   }
   requests = [];

}

default { 

   state_entry()
   {
       llRequestURL();
   }

   http_request(key id, string method, string body)
   {
       if (method == URL_REQUEST_GRANTED)
       {
           llSay(0,"URL: " + body);
       }
       else if (method == URL_REQUEST_DENIED)
       {
           llSay(0, "Something went wrong, no url. " + body);
       }
       else if (method == "GET")
       {
           if (!scanning)
           {
               llSensor("",NULL_KEY,AGENT,96,PI);
               scanning = TRUE;
           }
           
           requests += [id];
       }
       else
       {
           llHTTPResponse(id,405,"Unsupported method.");
       }
   }

   no_sensor()
   {
       send_response("There is no one here.");
       scanning = FALSE;
   }

   sensor(integer n)
   {
       string output;
       if (n < 16) output = "There are " + (string)n + " avatars nearby:";
       else output = "There are at least 16 avatars nearby:";
       
       integer i;
       for (i = 0;i<n;++i)
       {
           output += "\n\t" + llDetectedName(i);
       }
       
       send_response(output);

       scanning = FALSE;
   }

} </lsl>

Url Persistence / Visitor Counter

A more complete 'hello world', always has an url and keeps a visitor counter. <lsl> string url; integer hits;

setup() { 

   llSetObjectName("HTTP Server");
   url = "";
   llRequestURL();
   hits = (integer)llGetObjectDesc();
   llSetText((string)hits + " visitors.",<1,1,0>,1);

}

default { 

   state_entry() { setup(); }
   on_rez(integer n) { setup(); }
   
   changed(integer c)
   {
       if (c & (CHANGED_REGION | CHANGED_REGION_START | CHANGED_TELEPORT) )
       {
           setup();
       }
   }
   
   touch_start(integer n)
   {
       llSay(0,"My url is: " + url);
   }

   http_request(key id, string method, string body)
   {
       if (method == URL_REQUEST_GRANTED)
       {
           url = body;
       }
       else if (method == URL_REQUEST_DENIED)
       {
           llSay(0, "Something went wrong, no url. " + body);
       }
       else if (method == "GET")
       {
           ++hits;
           llSetObjectDesc((string)hits);
           llSetText((string)hits + " visitors.",<1,1,0>,1);
           llHTTPResponse(id,200,"Hello!  You are visitor " + (string)hits + ".");
       }
       else
       {
           llHTTPResponse(id,405,"Method unsupported");
       }
   }

} </lsl>


Perl/Python Examples Using POST

Here are a set of scripts to provide another example using POST. The first script is the LSL code to receive the information on the grid. The second script is a PERL script that is used on the outside server to contact the code on the grid. The third script is a Python script that is also used on the outside server to contact the code on the grid. (Grandma Bates 12:42, 27 May 2009 (UTC)) <lsl> key requestURL;

default { 

   state_entry() {
       requestURL = llRequestURL();     // Request that an URL be assigned to me.
   }
   
   
    http_request(key id, string method, string body) {
       
       if ((method == URL_REQUEST_GRANTED) && (id == requestURL) ){
           // An URL has been assigned to me.
           llOwnerSay("Obtained URL: " + body);
           requestURL = NULL_KEY;
       }
       
       
       else if ((method == URL_REQUEST_DENIED) && (id == requestURL)) {
           // I could not obtain a URL
           llOwnerSay("There was a problem, and an URL was not assigned: " + body);
           requestURL = NULL_KEY;
       }

       else if (method == "POST") {
           // An incoming message was received.
           llOwnerSay("Received information from the outside: " + body);
           llHTTPResponse(id,200,"Thank you for calling. All of our operators are busy.");
       }



       else {
           // An incoming message has come in using a method that has not been anticipated.
           llHTTPResponse(id,405,"Unsupported Method");
       }
   }

} </lsl>

Here is the PERL script to contact the prim on the grid.

<perl>

  1. !/usr/bin/perl
  2. Routine to contact a script on the SL Grid using http server

use LWP; require HTTP::Request; use URI::Escape; use strict;


  1. #################################################
  2. Routine to send the information to the prim
  3. submitInformation($url,$information)

sub submitInformation{ 

   # First get the arguments.
   my $url = shift;
   my $information = shift;

   # Create the objects to be used to send out the HTTP request
   my $browser = LWP::UserAgent->new;
   my $request = HTTP::Request->new(POST => $url);

   # Set the encoding method and specify the information to be sent.
   $request->content_type('application/x-www-form-urlencoded');
   $request->content(uri_escape($information));

   # Send the request.
   my $response = $browser->request($request);

   # Return the information sent back
   return($response->content);

}


  1. Set the URL manually....

my $url = 'http://sim3015.aditi.lindenlab.com:12046/cap/d57a7c8b-3ace-3186-730a-f22fde870d48';

my $info = submitInformation 

   ($url,'id=244195d6-c9b7-4fd6-9229-c3a8b2e60e81&name=M Linden');

print $info,"\n"; </perl>

Here is the Python code that does the same thing as the PERL code above.

<python>

  1. !/usr/bin/python

import urllib


  1. #################################################
  2. Routine to send the information to the prim
  3. submitInformation(url,information)

def submitInformation(url,parameters) : 

   # Set the parameters to be sent.
   encodedParams =  urllib.urlencode(parameters);

   # Post the data.
   net = urllib.urlopen(url,encodedParams);

   # return the result.
   return(net.read());


if __name__ == "__main__": 

   # Set the URL manually
   url = 'http://sim3015.aditi.lindenlab.com:12046/cap/d57a7c8b-3ace-3186-730a-f22fde870d48';

   # Define the parameters
   parameters = {'id':'244195d6-c9b7-4fd6-9229-c3a8b2e60e81',
                 'name':'M Linden'}

   # Pass the information along to the prim
   info = submitInformation(url,parameters);
   print(info);

</python>

Perl/Python Examples Using POST With Argument Parsing

Here are a set of scripts to provide another example using POST. In this example the scripts are adapted to handle the parsing of the arguments that are passed. The first script is the LSL code to receive the information on the grid. The second script is a PERL script that is used on the outside server to contact the code on the grid. The third script is a Python script that is also used on the outside server to contact the code on the grid. (Grandma Bates 12:42, 27 May 2009 (UTC))

<lsl> key requestURL;

// ############################################### // Routine to parse a string sent through the // http server via post. // parsePostData(theMessage) // Returns a strided list with stride length 2. // Each set has the key and then its value. list parsePostData(string message) { 

   list postData = [];         // The list with the data that was passed in.
   list parsedMessage = llParseString2List(message,["&"],[]);    // The key/value pairs parsed into one list.
   integer len = ~llGetListLength(parsedMessage);

   while(++len) {          
       string currentField = llList2String(parsedMessage, len); // Current key/value pair as a string.

       integer split = llSubStringIndex(currentField,"=");     // Find the "=" sign
       if(split == -1) { // There is only one field in this part of the message.
           postData += [llUnescapeURL(currentField),""];  
       } else {
           postData += [llUnescapeURL(llDeleteSubString(currentField,split,-1)), llUnescapeURL(llDeleteSubString(currentField,0,split))];
       }
   }
   // Return the strided list.
   return postData ;

}

default { 

   state_entry() {
       requestURL = llRequestURL(); // Request that an URL be assigned to me.
   }
   
   http_request(key id, string method, string body) {
        list incomingMessage;
       
       if ((method == URL_REQUEST_GRANTED) && (id == requestURL) ){
           // An URL has been assigned to me.
           llOwnerSay("Obtained URL: " + body);
           requestURL = NULL_KEY;
       }
       else if ((method == URL_REQUEST_DENIED) && (id == requestURL)) {
           // I could not obtain a URL
           llOwnerSay("There was a problem, and an URL was not assigned: " + 
                      body);
           requestURL = NULL_KEY;
       }
       else if (method == "POST") {
           // An incoming message was received.
           llOwnerSay("Received information form the outside: " + body);
           incomingMessage = parsePostData(body);
           llOwnerSay(llDumpList2String(incomingMessage,"\n"));

           llHTTPResponse(id,200,"You passed the following:\n" + 
                          llDumpList2String(incomingMessage,"\n"));

       }
       else {
           // An incoming message has come in using a method that has
           // not been anticipated.
           llHTTPResponse(id,405,"Unsupported Method");
       }
   }

} </lsl>

Here is the coresponding PERL script for contacting the LSL script on the grid.

<perl>

  1. !/usr/bin/perl
  2. Routine to contact a script on the SL Grid using http server

use LWP; require HTTP::Request; use URI::Escape; use strict;


  1. #################################################
  2. Routine to send the information to the prim
  3. submitInformation($url,$information)

sub submitInformation{ 


   my $url = shift;                   # First get the arguments.
   my $information = shift;

   my $browser = LWP::UserAgent->new;                # Create the object
   my $request = HTTP::Request->new(POST => $url);   # used to send the
                                                     # HTTP request

   $request->content_type                            # Set the

('application/x-www-form-urlencoded'); # encoding type. 

   $request->content(hash2URI($information));        # Set the content to
                                                     # send.

   my $response = $browser->request($request);       # Send the request.
   return($response->content);                       # Return the

# information that # was sent back }


  1. #########################################################################
  2. Convert a hash to a url encoded string
  3. hash2URI(\%hash)

sub hash2URI { 

   my $theHash = shift;            # Get the arguments passed.
   my $encodedString = ;         # The encoded string to return.
   my $lupe;                       # a loop variable.



   foreach $lupe (keys %{$theHash}) {                #

$encodedString .= uri_escape($lupe) . '=' . # Add each item in the uri_escape($$theHash{$lupe}) . '&'; # hash to the encoded string. 

   }
   $encodedString =~ s/&$//;                         # Remove the trailing "&"
   return($encodedString);                           # Send the encoded string.

}


  1. Set the URL manually....

my $url = 'http://sim3015.aditi.lindenlab.com:12046/cap/5a1b89cd-e681-8110-7245-fb98969f32a0';

my $info = submitInformation 

   ($url,{'action' => 'send message',

'value'=> 'Hi there chief!', 'id'=>'244195d6-c9b7-4fd6-9229-c3a8b2e60e81', 'name'=>'M Linden'});

print($info,"\n");


</perl>


Here is the coresponding Python script. It does the same thing as the PERL script above.

<python>

  1. !/usr/bin/python

import urllib import re

  1. #################################################
  2. Routine to send the information to the prim
  3. submitInformation(url,information)

def submitInformation(url,parameters) :

  1. encodedParams = urllib.urlencode(parameters); # encode the parameters
   encodedParams  = dictionary2URI(parameters);    # encode the parameters
   net = urllib.urlopen(url,encodedParams);        # Post the data.
   return(net.read());                             # return the result.



  1. ################################################
  2. Routine to encode a dictionary without using
  3. "+" for spaces.
  4. dictionary2URI(theDictionary)

def dictionary2URI(theDictionary) : 

   encoded = ;           # Initialize the string to return
   for key, value in theDictionary.iteritems():
       # Encode each item in the dictionary.
       encoded += urllib.quote(key)+"="+urllib.quote(value)+"&";

   remove = re.compile('&$')             # Remove the trailing ampersand.
   encoded = remove.sub(,encoded);

   return(encoded);


if __name__ == "__main__": 

   # Set the URL manually
   url = 'http://sim3015.aditi.lindenlab.com:12046/cap/5a1b89cd-e681-8110-7245-fb98969f32a0';

   # Define the parameters
   parameters = {'id':'244195d6-c9b7-4fd6-9229-c3a8b2e60e81',
                 'name':'M Linden',
                 'action':'send message',
                 'value':'Hey there, hi there, ho there!'};

   # Pass the information along to the prim
   info = submitInformation(url,parameters);
   print(info);

</python>

<lsl></lsl>


Simple script for sending data to an LSL via PHP

This example by Simba Fuhr

Warning!

Some hosting providers only allow fsockopen on the standard 80 and 443 ports. This script will not work on those providers.

<lsl> default { 

state_entry()
{
 llRequestURL();
}
http_request(key id, string method, string body)
{
 if ((method == URL_REQUEST_GRANTED))
 {
  llOwnerSay("URL: " + body);
 }
 else if (method == "POST")
 {
  llHTTPResponse(id, 200, body + " there !");
 }
}

} </lsl>

Here the PHP. It sends "Hello" to the LSL Script which adds " there !" and returns it, so the php will return "Hello there !"

<php> <?php $Data = CallLSLScript("http://sim3015.aditi.lindenlab.com:12046/cap/5a1b89cd-e681-8110-7245-fb98969f32a0", "Hello"); die($Data);

//Function by Simba Fuhr //Use under the GPL License function CallLSLScript($URL, $Data, $Timeout = 10) { 

//Parse the URL into Server, Path and Port
$Host = str_ireplace("http://", "", $URL);
$Path = explode("/", $Host, 2);
$Host = $Path[0];
$Path = $Path[1];
$PrtSplit = explode(":", $Host);
$Host = $PrtSplit[0];
$Port = $PrtSplit[1];

//Open Connection
$Socket = fsockopen($Host, $Port, $Dummy1, $Dummy2, $Timeout);
if ($Socket)
{
 //Send Header and Data
 fputs($Socket, "POST /$Path HTTP/1.1\r\n");
 fputs($Socket, "Host: $Host\r\n");
 fputs($Socket, "Content-type: application/x-www-form-urlencoded\r\n");
 fputs($Socket, "User-Agent: Opera/9.01 (Windows NT 5.1; U; en)\r\n");
 fputs($Socket, "Accept-Language: de-DE,de;q=0.9,en;q=0.8\r\n");
 fputs($Socket, "Content-length: ".strlen($Data)."\r\n");
 fputs($Socket, "Connection: close\r\n\r\n");
 fputs($Socket, $Data);
  
 //Receive Data
 while(!feof($Socket))
  {$res .= fgets($Socket, 128);}
 fclose($Socket);
}
 
//ParseData and return it
$res = explode("\r\n\r\n", $res);
return $res[1];

} ?> </php>

Kelly's Stupid Web Status Updater

Is actually on its own page: Kelly's Stupid Web Status Updater
Kurai's mod from Kelly's stupid thing: Kurai's Stupid Web Status Updater Mod

Grid URL Persister sample script

This script shows how to use the free Grid URL Persister web service in order to deal with LSL HTTP Server temporary URLs.

Web-based dynamic buildings

HTTP-in may be used to easily send commands from a web page to an in-world object, so that web users can control and interact with buildings. The interactive installation Chromutate is based upon this idea: see its documentation page for free scripts and more details.

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