View source for Lua:IPC

= Lua: IPC - Communication between Scripts =
If you have several scripts, which access the same data, you can have one script, which manages this data and one or more scripts reading (or writing) this data. 

For communication between these scripts, use the [[Lua_Mod_API#modules|et.IPCSend()]] and [[Lua_Mod_API#miscellaneous_2|et_IPCReceive( )]] functions. You cannot receive some data and send it back in the same (server) frame. These example scripts illustrate how to pass requests and the answers back and forth.

The '''ipcdemo-admin.lua''' script must be loaded first (i.e. earlier in the [[Lua_Mod_API#lua_modules|lua_modules]] cvar) otherwise the '''ipcdemo-cmd.lua''' cannot find it.

== ipcdemo-admin.lua ==
 <font color="#ff6060">-- ipcdemo-admin.lua</font>
 <font color="#8080ff"><b>local</b></font> IPCQueue = <font color="#8080ff"><b>{}</b></font>
 <font color="#8080ff"><b>local</b></font> AdminGUIDs = <font color="#8080ff"><b>{</b></font>
         <font color="#ff6060">-- name,       guid,                              level</font>
         <font color="#8080ff"><b>{</b></font> <font color="darkgreen">&quot;Vetinari&quot;</font>, <font color="darkgreen">&quot;ABCDEF1234567890ABCDEF1234567890&quot;</font>, <font color="darkgreen">5</font> <font color="#8080ff"><b>}</b></font>,
         <font color="#8080ff"><b>{</b></font> <font color="darkgreen">&quot;Havelock&quot;</font>, <font color="darkgreen">&quot;1234567890ABCDEF1234567890ABCDEF&quot;</font>, <font color="darkgreen">3</font> <font color="#8080ff"><b>}</b></font>
     <font color="#8080ff"><b>}</b></font>
 &nbsp;
 <font color="#0000ff">function</font> et_InitGame(levelTime, randomSeed, restart)
      et.RegisterModname(<font color="darkgreen">&quot;ipcdemo-admin.lua&quot;</font>)
 <font color="#0000ff">end</font>
 &nbsp;
 <font color="#0000ff">function</font> et_IPCReceive(vm, msg)
     <font color="#8080ff"><b>local</b></font> level
     <font color="#8080ff"><b>local</b></font> junk1, junk2, id = <font color="#0000ff">string.find</font>(msg, <font color="darkgreen">&quot;IsAdmin:%s+(%d+)&quot;</font>)
     <font color="#8080ff"><b>if</b></font> id ~= <font color="darkgreen">nil</font> <font color="#8080ff"><b>then</b></font>
         id    = <font color="#0000ff">tonumber</font>(id)
         guid  = et.Info_ValueForKey(et.trap_GetUserinfo(id), <font color="darkgreen">&quot;cl_guid&quot;</font>)
         level = table.foreach(AdminGUIDs,
             <font color="#0000ff">function</font>(i, admin)
                 <font color="#8080ff"><b>if</b></font> admin[<font color="darkgreen">2</font>] == guid <font color="#8080ff"><b>then</b></font>
                     <font color="#8080ff"><b>return</b></font>(admin[<font color="darkgreen">3</font>])
                 <font color="#8080ff"><b>end</b></font>
             <font color="#0000ff">end</font>
         )
         <font color="#8080ff"><b>if</b></font> level == <font color="darkgreen">nil</font> <font color="#8080ff"><b>then</b></font>
             level = <font color="darkgreen">0</font>
         <font color="#8080ff"><b>end</b></font>
         <font color="#0000ff">table.insert</font>(IPCQueue, <font color="#8080ff"><b>{</b></font> vm, level, id <font color="#8080ff"><b>}</b></font>)
     <font color="#8080ff"><b>end</b></font>
 <font color="#0000ff">end</font>
 &nbsp;
 <font color="#0000ff">function</font> et_RunFrame(lvltime)
     table.foreach(IPCQueue,
         <font color="#0000ff">function</font>(i, queue)
             <font color="#8080ff"><b>local</b></font> ok = et.IPCSend(queue[<font color="darkgreen">1</font>],
                             <font color="#0000ff">string.format</font>(<font color="darkgreen">&quot;IsAdmin: %d %d&quot;</font>, queue[<font color="darkgreen">2</font>], queue[<font color="darkgreen">3</font>]))
             <font color="#8080ff"><b>if</b></font> ok ~= <font color="darkgreen">1</font> <font color="#8080ff"><b>then</b></font>
                 <font color="#8080ff"><b>local</b></font> mod, cksum = et.FindMod(queue[<font color="darkgreen">1</font>])
                 et.G_Print(<font color="#0000ff">string.format</font>(<font color="darkgreen">&quot;ipcdemo-admin: IPCSend to %s (vm: %d) failed&quot;</font>, mod, queue[<font color="darkgreen">1</font>]))
             <font color="#8080ff"><b>end</b></font>
         <font color="#0000ff">end</font>
     )
     IPCQueue = <font color="#8080ff"><b>{}</b></font>
 <font color="#0000ff">end</font>

== ipcdemo-cmd.lua ==
 <font color="#ff6060">-- ipcdemo-cmd.lua</font>
 <font color="#8080ff"><b>local</b></font> admin_vm    = -<font color="darkgreen">1</font>
 <font color="#8080ff"><b>local</b></font> CommandQueue = <font color="#8080ff"><b>{}</b></font>
 &nbsp;
 <font color="#0000ff">function</font> et_InitGame(levelTime, randomSeed, restart)
     <font color="#8080ff"><b>local</b></font> mod = <font color="darkgreen">&quot;&quot;</font>
     <font color="#8080ff"><b>local</b></font> sig = <font color="darkgreen">&quot;&quot;</font>
     <font color="#8080ff"><b>local</b></font> i = <font color="darkgreen">1</font>
     <font color="#8080ff"><b>while</b></font> mod ~= <font color="darkgreen">nil</font> <font color="#8080ff"><b>do</b></font>
         mod, sig = et.FindMod(i)
         <font color="#8080ff"><b>if</b></font> <font color="#0000ff">string.find</font>(mod, <font color="darkgreen">&quot;^ipcdemo-admin.lua&quot;</font>) == <font color="darkgreen">1</font> <font color="#8080ff"><b>then</b></font>
             admin_vm = i
             mod      = <font color="darkgreen">nil</font>
         <font color="#8080ff"><b>end</b></font>
         i = i + <font color="darkgreen">1</font>
     <font color="#8080ff"><b>end</b></font>
     <font color="#8080ff"><b>if</b></font> admin_vm == -<font color="darkgreen">1</font> <font color="#8080ff"><b>then</b></font>
         et.G_Print(<font color="darkgreen">&quot;ipcdemo-cmd.lua: Could not find vm number for ipcdemo-admin.lua&quot;</font>)
     <font color="#8080ff"><b>end</b></font>
     et.RegisterModname(<font color="darkgreen">&quot;ipcdemo-cmd.lua&quot;</font>)
 <font color="#0000ff">end</font>
 &nbsp;
 <font color="#0000ff">function</font> et_IPCReceive(vm, msg)
     <font color="#8080ff"><b>if</b></font> vm == admin_vm <font color="#8080ff"><b>then</b></font>
         <font color="#8080ff"><b>local</b></font> junk1,junk2,level,id = <font color="#0000ff">string.find</font>(msg, <font color="darkgreen">&quot;IsAdmin:%s+(%d+)%s+(%d)&quot;</font>)
         <font color="#8080ff"><b>if</b></font> level ~= <font color="darkgreen">nil</font> <font color="#8080ff"><b>and</b></font> id ~= <font color="darkgreen">nil</font> <font color="#8080ff"><b>then</b></font>
             runAction(<font color="#0000ff">tonumber</font>(id), <font color="#0000ff">tonumber</font>(level))
         <font color="#8080ff"><b>end</b></font>
     <font color="#8080ff"><b>end</b></font>
 <font color="#0000ff">end</font>
 &nbsp;
 <font color="#0000ff">function</font> runAction(id, level)
     <font color="#8080ff"><b>local</b></font> done = table.foreach(CommandQueue,
         <font color="#0000ff">function</font>(i, queue)
             <font color="#8080ff"><b>if</b></font> id == queue[<font color="darkgreen">1</font>] <font color="#8080ff"><b>then</b></font>
                 <font color="#8080ff"><b>if</b></font> queue[<font color="darkgreen">2</font>] &lt;= level <font color="#8080ff"><b>then</b></font>
                     <font color="#8080ff"><b>if</b></font> queue[<font color="darkgreen">4</font>] == <font color="darkgreen">nil</font> <font color="#8080ff"><b>then</b></font>
                         et.trap_SendConsoleCommand(et.EXEC_INSERT, queue[<font color="darkgreen">3</font>])
                     <font color="#8080ff"><b>else</b></font>
                         et.trap_SendConsoleCommand(et.EXEC_INSERT,
                                 <font color="#0000ff">string.format</font>(<font color="darkgreen">&quot;%s %s&quot;</font>, queue[<font color="darkgreen">3</font>], queue[<font color="darkgreen">4</font>]))
                     <font color="#8080ff"><b>end</b></font>
                 <font color="#8080ff"><b>end</b></font>
                 <font color="#8080ff"><b>return</b></font>(i)
             <font color="#8080ff"><b>end</b></font>
         <font color="#0000ff">end</font>
     )
     <font color="#8080ff"><b>if</b></font> done ~= <font color="darkgreen">nil</font> <font color="#8080ff"><b>then</b></font>
         <font color="#0000ff">table.remove</font>(CommandQueue, done)
     <font color="#8080ff"><b>end</b></font>
 <font color="#0000ff">end</font>
 &nbsp;
 <font color="#0000ff">function</font> et_ClientCommand(id, command)
     <font color="#8080ff"><b>local</b></font> arg0 = et.trap_Argv(<font color="darkgreen">0</font>)
     <font color="#8080ff"><b>local</b></font> arg1 = et.trap_Argv(<font color="darkgreen">1</font>)
     <font color="#8080ff"><b>if</b></font> arg0 == <font color="darkgreen">&quot;say&quot;</font> <font color="#8080ff"><b>then</b></font>
         <font color="#8080ff"><b>if</b></font> arg1 == <font color="darkgreen">&quot;!axis&quot;</font> <font color="#8080ff"><b>then</b></font>
             <font color="#ff6060">--          id, lvl, cmd,         argument</font>
             queueCommand(id, <font color="darkgreen">4</font>, <font color="darkgreen">&quot;forceteam r&quot;</font>, id)
         <font color="#8080ff"><b>elseif</b></font> arg1 == <font color="darkgreen">&quot;!allies&quot;</font> <font color="#8080ff"><b>then</b></font>
             queueCommand(id, <font color="darkgreen">4</font>, <font color="darkgreen">&quot;forceteam b&quot;</font>, id)
         <font color="#8080ff"><b>elseif</b></font> arg1 == <font color="darkgreen">&quot;!shuffle&quot;</font> <font color="#8080ff"><b>then</b></font>
             queueCommand(id, <font color="darkgreen">3</font>, <font color="darkgreen">&quot;shuffleteamsxp_norestart&quot;</font>, <font color="darkgreen">nil</font>)
         <font color="#8080ff"><b>end</b></font>
     <font color="#8080ff"><b>end</b></font>
     <font color="#8080ff"><b>return</b></font>(<font color="darkgreen">0</font>)
 <font color="#0000ff">end</font>
 &nbsp;
 <font color="#0000ff">function</font> queueCommand(id, level, cmd, argument)
     <font color="#8080ff"><b>if</b></font> admin_vm ~= -<font color="darkgreen">1</font> <font color="#8080ff"><b>then</b></font>
         <font color="#8080ff"><b>local</b></font> ok = et.IPCSend(admin_vm, <font color="#0000ff">string.format</font>(<font color="darkgreen">&quot;IsAdmin: %d&quot;</font>, id))
         <font color="#8080ff"><b>if</b></font> ok ~= <font color="darkgreen">1</font> <font color="#8080ff"><b>then</b></font>
             et.G_Print(<font color="darkgreen">&quot;ipcdemo-cmd: IPCSend to ipcdemo-admin failed&quot;</font>)
         <font color="#8080ff"><b>else</b></font>
             <font color="#0000ff">table.insert</font>(CommandQueue, <font color="#8080ff"><b>{</b></font> id, level, cmd, argument <font color="#8080ff"><b>}</b></font>)
         <font color="#8080ff"><b>end</b></font>
     <font color="#8080ff"><b>end</b></font>
 <font color="#0000ff">end</font>

[[Category:Lua]]