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OpenSim Scripting Languages: LSL and OSSL | Justincc's OpenSimulat...http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-...2 of 8 6/30/2012 9:48 PMAugust 2010July 2010June 2010May 2010April 2010March 2010February 2010January 2010December 2009November 2009October 2009September 2009August 2009July 2009June 2009May 2009April 2009March 2009February 2009January 2009December 2008November 2008October 2008September 2008August 2008July 2008June 2008May 2008April 2008OpenSim Scripting Languages: LSL andOSSLOctober 24, 2008By justinccIntroductionDespite our long term desire to see OpenSim become a general virtual environmentplatform, implementing all the functions in the Linden Scripting Language (LSL) for theSecond Life environment has become one of our de facto aims. This is veryunderstandable for two reasons1. There is a large stock of Second Life scripts already written in LSL. The moreaccurately our implementation of LSL, the easier it is to reuse that existing code.2. The syntax and ll functions of LSL effectively constitute a language specification.This allows lots of different open source contributors to work in ‘bazaar‘ fashion.Many different people can contribute patches that implement ll functionspiecemeal, with no need to co-ordinate their efforts with other open sourcecontributors.However, LSL is imperfect. Leaving aside any questions about the inconsistency ofLinden Lab’s ll function implementations or the deficiencies of the language itself, there

OpenSim Scripting Languages: LSL and OSSL | Justincc's OpenSimulat...http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-...3 of 8 6/30/2012 9:48 PMis also a lot of missing functionality. For instance, in LSL one cannot teleport an agent(instead various imperfect workarounds have to be used). Neither can one write data tonotecards, or find out information about avatar group roles.OpenSimulator Scripting Language (OSSL)How could the problem of missing functionality be addressed? If we leave aside theprospect of using completely different languages with their own functionimplementations (C#, Python, etc.), one way to do it is to extend LSL by adding extrafunctions that OpenSim understands. This is what the OpenSimulator ScriptingLanguage (OSSL) is. It is effectively all of LSL plus extra functions that start with an osprefix. os functions can be used in a script in exactly the same way as ll functions areused. Examples of os functions areosTeleportAgent() allows you to teleport an agent to another position and region.osSetDynamicTextureURL() allows you to display an external or dynamicallygenerated image inworld (as used in this inworld webpage display script or myown ‘graffiti board’ script that displays text on a single texture in-world.osParseJSON() allows you to parse JSON within a script. This isn’t such a goodexample as the HashTable return type probably makes it unusable currently in LSLscripts (the example here is a script in compiled C#). However, I think it could beextended to return a data structure that could be used in LSL.How to implement an OSSL functionImplementing an OSSL function is a little fiddly – you need to make changes in 3 places.First, let’s do the actual implementation itself. Just as there exists an LSL_Api class inthe OpenSim.Region.ScriptEngine.Shared.Api package that implements all the LSLfunctions, so there is an OSSL_Api class that implements OSSL functions. Toimplement a new function, one would add a method with the same name inOSSL_Api.cs. For examplepublic string osMyFunction(){// We'll talk about this in the next sectionCheckThreatLevel(ThreatLevel.None, "osMyFunction");// Let stats know that a script line has been executedm_host.AddScriptLPS(1);}return "Hello World!";The method signature for this implementation needs to be added to the interfaceIOOSL_Api in OpenSim.Region.ScriptEngine.Shared (Api/Interface directory)string osMyFunction();Finally, a method to call the function via this interface must be added to theScriptBaseClass (which underlies all LSL and OSSL scripts) in the OSSL_Stub.cs file inpackage OpenSim.Region.ScriptEngine.Shared.Api.Runtime.public string osMyFunction(){return m_OSSL_Functions.osMyFunction();}Then it’s a case of recompiling OpenSim and restarting the region server. Before yourestart, make sure thatAllowOSFunctions = trueis set in your OpenSim.ini. If this isn’t set then no os function will run no matter whatthreat level is set (as discussed below).Once you’ve restarted OpenSim, you can invoke osMyFunction() in an in-world scriptdefault{state_entry(){llSay(0, osMyFunction());}}

OpenSim Scripting Languages: LSL and OSSL | Justincc's OpenSimulat...http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-...5 of 8 6/30/2012 9:48 PM5.justincc on January 23, 2009 at 3:56 pmOSSL_Api.cs is actually in the source code at OpenSim/Region/ScriptEngine/Shared/Api/Implementation/OSSL_Api.csAs you pointed out to me by e-mail, this is a list of functions at http://opensimulator.org/wiki/OSSL_Implemented6.Ai Austin on January 23, 2009 at 9:40 pmAh, thanks Justin. You blog here also says you can individually enable/dispableosFunctions… is that mutually separate to setting the threat level, and where can you doit – is it in opensim.ini?If I want to say allow 3 specific osFunctions and no others, wehatever their threat level,how is that done?7.justincc on January 25, 2009 at 5:59 pmYes, I see this isn’t documented very well – there isn’t even anything inOpenSim.ini.example for this. There might be something on the wiki but I don’t knowwhere. A link would be appreciated if you can find one.From reading the code, it looks like a setting in OpenSim.ini in the [XEngine] or[ScriptEngine.DotNetEngine] sections such asAllow_osTeleportAgent = truewould allow it for everybody no matter what threat level threshold was set (and as long asthe general AllowOSFunctions switch is true).On the other hand, it looks like one can also supply a list of UUIDs for users so that onlyscripts owned by that user can execute that function. For instance,Allow_osTeleportAgent = 36bff189-1a29-41dd-aeaa-81139148ec08would allow only scripts owned by the user denoted by uuid 36bff189-1a29-41ddaeaa-81139148ec08to execute osTeleportAgent().8.Ai Austin on January 25, 2009 at 10:48 pmThanks, I will test with that.Can yo tell if the default for AllowOSFunctions is false as I suspect? If so we should getthe opensim.ini.example file amended… it current states the default is true. Can youcheck and make that change to get everything in sync as a developper Justin?Also, it would be great to get the osSetDynamicTextureData full function set documentedon the Wiki, and the 2 examples in the distrtibution lined explicity to the Wiki page so allthe xanmplesa are available to a wilki broswer.9.Ai Austin on January 26, 2009 at 11:22 amI found that the list of osSetDynamic TextureData functions is available athttp://opensimulator.org/wiki/OSSL_TextureDrawingThough te 3example is a C# one which I am not sure how to compile as I haveDotNetEngione enabed.I added the function list as a link inhttp://opensimulator.org/wiki/OSSL_Implemented

OpenSim Scripting Languages: LSL and OSSL | Justincc's OpenSimulat...http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-...6 of 8 6/30/2012 9:48 PMThe Opensim Wiki is difficult to fund one way round.10.justincc on January 30, 2009 at 9:09 pmI correct the information in OpenSim.ini.example about AllowOSFunctions in r8184.Filling out the functions I’m afraid I will have to leave to somebody else, since I have toprioritize my (always) limited timeYou might be somewhat disturbed to know that while looking for the os functions page inthe wiki, I came across another one athttp://opensimulator.org/wiki/LSL_osFunctionsThis should really be amalgamated withhttp://opensimulator.org/wiki/OSSL_Implemented11.justincc on January 30, 2009 at 10:04 pmOops my mistake. The stuff on http://opensimulator.org/wiki/LSL_osFunctions is largelysuggestions for functions, not actually implemented ones.12.Nolo on February 7, 2009 at 8:23 pmI felt compelled to second the notion of Ai @ #8.“Also, it would be great to get the osSetDynamicTextureData full function setdocumented on the Wiki, and the 2 examples in the distrtibution lined explicity to theWiki page so all the xanmplesa are available to a wilki broswer.”I understand that it’s difficult to ask for such things and to do so leans toward optimism,but ANY help in the area of documentation would greatly serve /everybody’s/ cause todate. Calling all units – rapid fire reporting needed on site! I tend to border on theinsane though…13.justincc on February 8, 2009 at 6:53 pm@Nolo. Oh, I do agree, proper documentation would be very nice. Unfortunately, itseems that my fellow developers don’t always agree with me – hopefully this is an area inwhich we will improve as OpenSim matures.Actually, I believe that osSetDynamicTextureData is only a thin wrapper around a .NETlibrary function for drawing lines, text, etc. dynamically on a surface. So if one were tohunt that down in the .NET SDK documentation that might provide all the informationthat you need.14.Stefanie on June 3, 2010 at 4:40 pmthanks for providing this description, but how to implement events in OSSL?15.justincc on June 14, 2010 at 11:13 pmHi Stefanie. Unfortunately, I suspect that there’s no easy way to provide custom events inOSSL at this time without changing a lot of core OpenSim code.16.David on August 10, 2010 at 8:34 pm

OpenSim Scripting Languages: LSL and OSSL | Justincc's OpenSimulat...http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-...7 of 8 6/30/2012 9:48 PMGreat!!! Worked just fine. Recompiled with VS# 2008 Express, I’m testing my ownosFunctions on my Standalone region an all it´s ok!!Thanks17.AdelleF on October 22, 2010 at 11:45 pm18.Thanks for this Justin, it was a great help in my getting started with programmingOpenSimOpenSimulator Scripting Language (OOSL) and Linden Scripting Language (LSL) « TheEducational Technologist on September 6, 2011 at 12:19 am[...] http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-ossl/ SimOn A Stick [...]Leave a ReplyYour email address will not be published. Required fields are marked *Name *Email *WebsiteABOUT MEHi, I'm Justin Clark-Casey, an OpenSim coredeveloper andprofessional softwareengineer.On the Linden Lab gridI go by the name ofLulworth Beaumont. Onother grids I'm just plainold Justin Clark-Casey.I'm currently working asa freelance consultantspecializing inOpenSimulator andrelated technologies. Ifyou're interested inlearning more thenplease read the Hire Mepage.I've also written a paperon distributed virtualenvironments, whichexamines how virtualworlds could becomemore like the web,rather than individualsilos of users andcontent.

OpenSim Scripting Languages: LSL and OSSL | Justincc's OpenSimulat...http://justincc.org/blog/2008/10/24/opensim-scripting-languages-lsl-and-...8 of 8 6/30/2012 9:48 PMI often attend theOpenSim Office Hourson a Tuesday on WrightPlaza at OSgrid.orgMetaLog inEntries RSSComments RSSWordPress.orgBlogroll@jusincc onGitHub@justincc onLinked In@justincc onTwitterBlueWall's blogDiva Canto's blogEner Hax's blogHypergridBusinessKitelyMOSESOpenSimulatorOSgridScienceSimCopyright © 2012 Justincc's OpenSimulator blog. All Rights Reserved.Magazine Basic theme designed by Themes by bavotasan.com.Powered by WordPress.