Difference between revisions of "Script lua"

From The Foundry MODO SDK wiki
Jump to: navigation, search
(Created page with "Script_lua is a basic example plugin. This wiki page is intended as a walkthrough of the code in order to help you better understand the SDK. ==Functionality== This plugin ...")
(No difference)

Revision as of 19:05, 9 September 2013

Script_lua is a basic example plugin. This wiki page is intended as a walkthrough of the code in order to help you better understand the SDK.


Functionality

This plugin serves as a Lua script interpreter.

Code Walkthrough

Declarations

typedef struct st_IntrInstance {
       ILxScriptID	 script;		// Script being executed.
       ILxMonitorID	 monitor;		// Progress monitor used by lxmon??? functions.
       int		 askedForMonitor;	// True if we asked for the monitor.
       LxResult	 rc;			// Result code from the most recently executed/queried command.
       int		 tracing;		// 1 if tracing is active, 0 if inactive.
       int		 execFlags;		// Flags provided by the caller of Run() and used for command execution.

       CLxUser_LogEntry log;			// For logging data

       int		 queryAnglesAsDegrees;	// True if queried angles should be returned in degrees instead of radians.
} IntrInstance;

This is a struct that defines certain objects and constants that will be used by the plugin.

extern "C"  int   l_lxout(lua_State *L);
extern "C"  int   l_lx(lua_State *L);
extern "C"  int   l_lxq(lua_State *L);
extern "C"  int   l_lxqt(lua_State *L);
extern "C"  int   l_lxeval(lua_State *L);
extern "C"  int   l_lxok(lua_State *L);
extern "C"  int   l_lxres(lua_State *L);
extern "C"  int   l_lxtrace(lua_State *L);
extern "C"  int   l_lxoption(lua_State *L);
extern "C"  int   l_lxsetOption(lua_State *L);
extern "C"  int   l_lxmonInit(lua_State *L);
extern "C"  int   l_lxmonStep(lua_State *L);

Declaration of functions that will be used by the plugin.

extern "C" {

ILxScriptSysServiceID		 scriptSrv;			/* Script system service; common to all instances                */
ILxStdDialogServiceID		 dlgSrv;			/* Standard dialog service; common to all instances              */
IntrInstance			 intrStack[ MAX_STACK ];	/* Interpreter stack; allows scripts to execute other scripts    */
int				 intrTop        = -1;		/* The current script being executed as an index into interStack */
IntrInstance			*intrCur        = NULL;		/* The same as &intrStack[ intrTop ], or NULL if intrTop is -1   */

}

Here we declare a variety of scripts and services that will be used below. "extern" indicates that the objects inside have already been defined elsewhere so the compiler won't complain.

Class Declarations

class CLuaInterpreter : public CLxImpl_TextScriptInterpreter
{
       CLxUser_LogService	logSvc;
       CLxUser_CommandService	cmdSvc;
       CLxUser_ValueService	valueSvc;

   public:
       virtual			~CLuaInterpreter () {}

       virtual LxResult	 tsi_ValidateFileType (
                                       ILxUnknownID	 scriptObj,
                                       const char	*firstLine) LXx_OVERRIDE;
       virtual LxResult	 tsi_Run (
                                       ILxUnknownID	 scriptObj,
                                       int		 execFlags,
                                       const char	*args,
                                       ILxUnknownID	 messObj) LXx_OVERRIDE;
        
       void			 Init ();
       void			 Kill ();
 
       static LXtTagInfoDesc	 descInfo[];

   private:
       lua_State		*L;
};

This class is intended to take a lua script and interpret it, so we need it to be a modified text editor. To this end, we inherit from CLxImpl_TextScriptInterpreter.

Server Tags

The tags here indicate that CLuaInterpreter has the name Lua Scripts and takes files with the .lua extension.

Initialize

       void
initialize ()
{
       LXx_ADD_SERVER (TextScriptInterpreter, CLuaInterpreter, "lua");
} 

This initialize function exports one server of the type TextScriptInterpreter that is dependent on the class CLuaInterpreter and has the name lua.

Implementations

       static void 
AddLogStringEntry (
       CLxLoc_LogEntry		&parent,
       const char		*s,
       LxResult		 code,
       int			 persist,
       CLxLoc_LogEntry		&entry)
{
       if (logSrv->NewEntry (code, s, entry)) {
               parent.AddEntry (entry);
       }
}

Add a string to a parent log, possibly returning a log entry for sub-entries

void
AddLogString (
       CLxLoc_LogEntry		&parent,
       const char		*s,
       LxResult		 code,
       int			 persist)
{ 
       CLxLoc_LogEntry		 entry;

       AddLogStringEntry (parent, s, code, persist, entry);
}

Adding a log entry to a parent, for clients with no need for the entry.

       void
LogString (
       const char		*s,
       LxResult		 code,
       int			 persist)
{
       CLxLoc_LogEntry		 entry;

       LogStringEntry (s, code, persist, entry);
}

Logging for clients with no need for the entry.

       int
l_lxout(lua_State *L)
{
       const char		*c = lua_tostring(L, 1);
         
       if(c)
               LogString( c, LXe_INFO, 0 );
       else
               LogString( "nil", LXe_INFO, 0 );

       return 0;
}

lxout: Output a string to the log

#define LXEVALMODEf_QUERY	1						// Query only; fail if no query is marked
#define LXEVALMODEf_EXECUTE	2						// Execute only; fail if a query is marked
#define LXEVALMODEf_EITHER	(LXEVALMODEf_QUERY | LXEVALMODEf_EXECUTE) 	// Query or execute, whatever works

       LxResult
lxeval(lua_State *L, int mode)
{
       CLxUser_Command		 command;
       CLxLoc_LogEntry		 entry;
       int			 i, x, type, queryArgIndex;
       int			 iVal;
       double			 fVal, fScalar = 1.0;
       char			 sVal[2048];
       const char		*typeName;
       LxResult		 rc;
       const LXtTextValueHint	*hints     = NULL;
       unsigned		 execFlags = intrCur->execFlags;
       const char		*c         = lua_tostring(L, 1);
       bool			 isOK;

       OutputTraceInfo( c, entry );

       /* Spawn the command and get the query argument */
       isOK = cmdSrv->NewCommandFromString (command, c, execFlags, queryArgIndex);
       if( !isOK ) {
               intrCur->rc = LXe_FAILED;

               if( intrCur->tracing )
                       AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxq/lx/lxeval failed: error spawning command/parsing arguments\03(f:FONT_DEFAULT)", LXe_FAILED, 0 );

               return LXe_FAILED;
       }

	if( (mode == LXEVALMODEf_EXECUTE) ||					// Execute only flag; execute if there's a query or not
           ((queryArgIndex == -1) && (mode & LXEVALMODEf_EXECUTE)) ) {		// No query arg; execute if the execute flag is set (in case of "either" mode)
               /* Execute */
               if( !(mode & LXEVALMODEf_EXECUTE) ) {
                       if( intrCur->tracing )
                               AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lx failed: unprocessed query argument (i.e., \'?\') specified in command   string\03(f:FONT_DEFAULT)",     
LXe_FAILED, 0 );

                       return LXe_FAILED;
               }

               intrCur->rc = cmdSrv->ExecuteSpecial( execFlags, command, queryArgIndex );
               lua_pushnumber(L, LXx_OK( intrCur->rc ) ? 1 : 0 );

               return LXe_OK;
       }

       /* See if we're allowed to query */
       if( !(mode & LXEVALMODEf_QUERY) ) {
               if( intrCur->tracing )
                       AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxq/lxeval failed: no query (i.e., \'?\') marked in command string\03(f:FONT_DEFAULT)", LXe_FAILED, 0 );

               return LXe_CMD_NO_QUERY_MARKED;
       }

       /* Create the value array and query the command */
       CLxUser_ValueArray	 qval;

       CLxUser_Attributes attr;
       if (attr.set(command)) {
               /* Get the type */
               type = attr.Type (queryArgIndex);
               if (type != -1) {
                       /* Get the type name */
                       rc = attr.TypeName (queryArgIndex, &typeName);

                       if (LXx_OK (rc)) {
                               /* Create a value array */
                               ILxUnknownID		 oqval;
                               rc = cmdSrv->CreateQueryObject( typeName, (void **)&oqval );
                               if (LXx_OK (rc)) {
                                       /* Query */
                                       qval.set (oqval);
                                       if( qval.set (oqval) )
                                               rc = command.Query (queryArgIndex, qval);
                               }
                       }
               }
               else {
                       rc = LXe_FAILED;
               }
       }

       if( LXx_FAIL (rc) ) {
               if( intrCur->tracing )
                       AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxq/lxeval failed: error querying command\03(f:FONT_DEFAULT)", LXe_FAILED, 0 );

               return rc;
       }

       /* Return the values in the value array to the script */
       i = qval.Count();

       if(0 == i) {
               /* Nothing is on the stack; return nil */
               lua_pushnil( L );
               return LXe_OK;
       }

       if( attr != NULL )
               hints = attr.Hints( queryArgIndex );

       lua_newtable(L);

       if( intrCur->queryAnglesAsDegrees ) {
               /* Special case:  convert angles to degrees, if applicable */
               if( strcmp( typeName, "angle" ) == 0 )
                       fScalar = 57.295780490442968321226628812406;	// 180 / 3.1415926;
       }

       for(x = 0 ; x < i ; x++)
       {
               lua_pushnumber(L, x+1);		// The key, which is just the index of the value

               if(type == LXi_TYPE_INTEGER) 
               {
                       bool asNumber = 1;

                       qval.GetInt (x, &iVal);
                       if( hints != NULL ) {
                               LxResult	encodeResult = valueSrv->TextHintEncode( iVal, hints, sVal, 2048 );
                               if( encodeResult != LXe_OK_NO_CHOICES ) {
                                       lua_pushlstring(L, sVal, strlen(sVal));
                                       asNumber = 0;

                                       if( intrCur->tracing ) {
                                               char buf[ 64 ];
                                               sprintf( buf, "\03(f:FONT_ITALIC)lxtrace, lxq, %d:\03(f:FONT_DEFAULT)  %s", x+1, sVal );
                                               AddLogString( entry, buf, LXe_INFO, 0 );
                                       }
                               }
                       }

                       if( asNumber ) {
                               lua_pushnumber(L, iVal);

                               if( intrCur->tracing ) {
                                       char buf[ 64 ];
                                       sprintf( buf, "\03(f:FONT_ITALIC)lxtrace, lxq, %d:\03(f:FONT_DEFAULT)  %d", x+1, iVal );
                                       AddLogString( entry, buf, LXe_INFO, 0 );
                               }
                       }
               }
               else if(type == LXi_TYPE_FLOAT) 
               {
                       qval.GetFloat (x, &fVal);
                       fVal *= fScalar;
                       lua_pushnumber(L, fVal);
 
                       if( intrCur->tracing ) {
                               char buf[ 64 ];
                               sprintf( buf, "\03(f:FONT_ITALIC)lxtrace, lxq, %d:\03(f:FONT_DEFAULT)  %g", x+1, fVal );
                               AddLogString( entry, buf, LXe_INFO, 0 );
                       }
               }
               else if(type == LXi_TYPE_STRING)
               {
                       qval.GetString (x, sVal, 2048);
                       lua_pushlstring(L, sVal, strlen(sVal));

                       if( intrCur->tracing ) {
                               char buf[ 2048 ];
                               sprintf( buf, "\03(f:FONT_ITALIC)lxtrace, lxq, %d:\03(f:FONT_DEFAULT)  %s", x+1, sVal );
                               AddLogString( entry, buf, LXe_INFO, 0 );
                       }
               }
               else
               {
                       /* Object; convert to a string and return */
                       char		 buffer[2048];

                       LXtObjectID		 value;
                       if( LXx_FAIL( (qval.GetValue (x, (void **) &value) ))) {
                               lua_pushnil( L );
                               continue;
                       }

                       /*
                        * Check if we have a string converter.
                        */
                       CLxUser_StringConversion	stringer;
                       stringer.set (value);
                       if (!stringer.test ()) {
                               lua_pushnil( L );
                               continue;
                       }

                       if( LXx_FAIL( stringer.Encode ( buffer, 2048 ) ) ) {
                               lua_pushnil( L );
                               continue;
                       }

                       lua_pushlstring(L, buffer, strlen(buffer));

                       if( intrCur->tracing ) {
                               char buf[ 2100 ];
                               sprintf( buf, "\03(f:FONT_ITALIC)lxtrace, lxq, %d:\03(f:FONT_DEFAULT)  %s", x+1, buffer );
                               AddLogString( entry, buf, LXe_INFO, 0 );
                       }
               }

               lua_settable(L, -3);
       }

       return 1;
}

Internal function to perform queries and executions

       int
l_lxq(lua_State *L)
{
       if( LXx_FAIL( lxeval( L, LXEVALMODEf_QUERY ) ) )
               return 0;

       return 1;
}

At some point in the future, lxq() needs to use the raw string conversion feature to ensure that the values that are queried are the same kinds of values that get passed to commands.

       int
l_lxqt(lua_State *L)
{
       CLxUser_Command		 command;
       CLxLoc_LogEntry		 entry;
       int			 state;
       unsigned		 execFlags = intrCur->execFlags;
       const char		*c         = lua_tostring(L, 1);
       bool			 isOK;

       OutputTraceInfo( c, entry );

       /* Spawn the command */
       int queryArgIndex;
       isOK = cmdSrv->NewCommandFromString( command, c, execFlags, queryArgIndex );
       if( !isOK ) {
               intrCur->rc = LXe_FAILED;

               if( intrCur->tracing )
                       AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxqt failed: error spawning command/parsing arguments\03(f:FONT_DEFAULT)", LXe_FAILED, 0 );

               lua_pushnumber( L, 0 );
               return 1;
       }

       /* Query the toggle argument */
       intrCur->rc = cmdSrv->GetToggleArgState( command, &state, NULL );

       if( intrCur->tracing ) {
               if( LXx_OK( intrCur->rc ) ) {
                       if( state ) {
                               AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxqt, toggled state is true (1)\03(f:FONT_DEFAULT)", LXe_INFO, 0 );
                               lua_pushnumber( L, 1 );
                       } else {
                               AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxqt, toggled state is false (0)\03(f:FONT_DEFAULT)", LXe_INFO, 0 );
                               lua_pushnumber( L, 0 );
                       }
               } else {
                       AddLogString( entry, "\03(f:FONT_ITALIC)lxtrace, lxqt failed: error querying the command\03(f:FONT_DEFAULT)", LXe_FAILED, 0 );
                       lua_pushnumber( L, 0 );
               }
       }

       return 1;
}

lxqt(): Query a toggle command's toggle argument. Returns the query state on success (1 or 0), or 0 on failure.

       int
l_lxok(lua_State *L)
{
       lua_pushboolean(L, LXx_OK( intrCur->rc ) ? 1 : 0);
       return 1;
}

Return true if the last command executed/queried successfully.

       int
l_lxres(lua_State *L)
{
       lua_pushnumber(L, intrCur->rc);
       return 1;
}

Return the LxResult code of the last command executed or quieried.

       int
l_lxtrace(lua_State *L)
{ 
       /* See if there's at least one argument */
       const char	*c = lua_tostring(L, 1);

       if( c != NULL ) {
               intrCur->tracing = atoi( c );	// For some reason, lua_toboolean() is always returning 1, so we'll just do this
               if( intrCur->tracing )
                       LogString( "\03(f:FONT_ITALIC)lxtrace: Enabled\03(f:FONT_DEFAULT)", LXe_INFO, 0 );
               else
                       LogString( "\03(f:FONT_ITALIC)lxtrace: Disabled\03(f:FONT_DEFAULT)", LXe_INFO, 0 );
       }

       lua_pushnumber(L, intrCur->tracing);
       return 1;
}

When activated, lx() and lxq() data is output to the event log. If no args are passed in, this returns if tracing is active or not.

       int
l_lxoption(lua_State *L)
{
       const char		*tag = lua_tostring(L, 1);

       if( strcmp( tag, "queryAnglesAs" ) == 0 ) {
               /* Query Angles As.  Returns "degrees" or "radians" */
               const char	*state = intrCur->queryAnglesAsDegrees ? "degrees" : "radians";
               lua_pushlstring(L, state, strlen(state));

               return 1;
       }

       /* Unknown tag */
       return 0;
}

Get the state of an option.

       int
l_lxsetOption(lua_State *L)
{
       const char		*tag   = lua_tostring(L, 1);
       const char		*value = lua_tostring(L, 2);

       if( strcmp( tag, "queryAnglesAs" ) == 0 ) {
               /* Query Angles As.  Returns "degrees" or "radians" */
               if( strcmp( tag, "queryAnglesAs" ) == 0 ) {
                       /* Query Angles As.  Supports "degrees" or "radians" */
                       if( strcmp( value, "degrees" ) == 0 ) {
                               intrCur->queryAnglesAsDegrees = 1;

                       } else if( strcmp( value, "radians" ) == 0 ) {
                               intrCur->queryAnglesAsDegrees = 0;

                       } else {
                               lua_pushboolean(L, 0);
                               return 0;
                       }

                       lua_pushboolean(L, 1);
               }

               return 1;
       }

       /* Unknown tag */
       lua_pushboolean(L, 0);
       return 0;
}

Get the state of an option.

       int
l_lxmonInit(lua_State *L)
{
       int		 count;
       LxResult	 rc;

       /* See if there's at least one argument */
       if( lua_tostring(L, 1) == NULL ) {
               lua_pushboolean(L, 0);
               return 1;
       }

       /* Make sure there's at least one step */
       count = (int)lua_tonumber(L, 1);
       if( count < 1 ) {
               lua_pushboolean(L, 0);
               return 1;
       }

       /* Get the monitor */
       if( intrCur->monitor == NULL ) {
               if( intrCur->askedForMonitor ) {
                       lua_pushboolean(L, 0);
                       return 1;
               }

               if( LXx_FAIL( dlgSrv[0]->MonitorAllocate( dlgSrv, "Progress", (void **)&intrCur->monitor ) ) || (intrCur->monitor == NULL) ) {
                       lua_pushboolean(L, 0);
                       return 1;
               }

               intrCur->askedForMonitor = 1;
       }

       /* Initialize the monitor */
       rc = intrCur->monitor[0]->Initialize( intrCur->monitor, count );
       if( LXx_OK( rc ) )
               lua_pushboolean(L, 1);
       else
               lua_pushboolean(L, 0);

       return 1;
} 

Initialize the progress bar. Initialize the progress bar with n total steps. Returns 0 on error.

       int
l_lxmonStep(lua_State *L)
{
       int		 steps;
       LxResult	 rc;

       if( intrCur->monitor == NULL ) {
               lua_pushboolean(L, 1);
               return 1;
       }

       /* See if there are any arguments */
       if( lua_tostring(L, 1) == NULL )
               steps = 1;
       else
               steps = (int)lua_tonumber(L, 1);

       /* Make sure there's at least one step */
       if( steps < 1 ) {
               lua_pushboolean(L, 1);
               return 1;
       }

       /* Increment the monitor and check for a user abort */
       rc = intrCur->monitor[0]->Increment( intrCur->monitor, steps );
       if( LXx_OK( rc ) )
               lua_pushboolean(L, 1);
       else
               lua_pushboolean(L, 0);

       return 1;
}

Step the progress bar. Increment the progress bar by n steps, or 1 step if no steps are provided. This always returns true unless the user aborts, in which case it returns false.

       LxResult
CLuaInterpreter::tsi_ValidateFileType (
       ILxUnknownID		  scriptObj,
       const char		 *firstLine)
{
       if (!strstr (firstLine, "lua"))
               return LXe_SCRIPT_UNKNOWN;
         
       return LXe_OK;

}	

verifies that the file passed in is of the lua type.

       void
CLuaInterpreter::Init()
{
       logSrv = &logSvc;
       cmdSrv = &cmdSvc;
       valueSrv = &valueSvc;

       L = lua_open();
        
       /* Add the new functions to lua */
       lua_pushcfunction(L, l_lxout);
       lua_setglobal(L, "lxout");
        
       lua_pushcfunction(L, l_lx);
       lua_setglobal(L, "lx");
        
       lua_pushcfunction(L, l_lxq);
       lua_setglobal(L, "lxq");

       lua_pushcfunction(L, l_lxqt);
       lua_setglobal(L, "lxqt");

       lua_pushcfunction(L, l_lxeval);
       lua_setglobal(L, "lxeval");

       lua_pushcfunction(L, l_lxok);
       lua_setglobal(L, "lxok");

       lua_pushcfunction(L, l_lxres);
       lua_setglobal(L, "lxres");

       lua_pushcfunction(L, l_lxtrace);
       lua_setglobal(L, "lxtrace");

       lua_pushcfunction(L, l_lxoption);
       lua_setglobal(L, "lxoption");

       lua_pushcfunction(L, l_lxsetOption);
       lua_setglobal(L, "lxsetOption");

       lua_pushcfunction(L, l_lxmonInit);
       lua_setglobal(L, "lxmonInit");
        
       lua_pushcfunction(L, l_lxmonStep);
       lua_setglobal(L, "lxmonStep");
 
       /* Other lua init */	

       /*
        * Updated for Lua 5.1, per the Lua API Programming FAQ:
        *
        * http://lua-users.org/wiki/LuaFaq
        *
        * See "Why do I get a 'no calling environment' error?"
        */
       luaL_openlibs(L);

       /* Init our level of the stack */
       intrTop++;
       assert( intrTop < MAX_STACK );

       intrCur = &intrStack[ intrTop ];
       intrCur->script               = NULL;
       intrCur->monitor              = NULL;
       intrCur->askedForMonitor      = 0;
       intrCur->rc                   = LXe_OK;
       intrCur->tracing              = 0;
       intrCur->execFlags            = LXfCMD_EXEC_DEFAULT;
       intrCur->queryAnglesAsDegrees = 1;
}

adds all of the functions just implemented in lxlua.cpp to CLuaInterpreter

       LxResult
CLuaInterpreter::tsi_Run (
       ILxUnknownID		 scriptObj,
       int			 execFlags,
       const char		*args,
       ILxUnknownID		 messObj )
{
       // Hybrid access: Let the localization handle the reference-counting, but
       // extract the interface for old-style direct usage.
       //
       CLxLoc_Script		 u_script (scriptObj);
       CLxLoc_Message		 u_mess   (messObj);
       ILxScriptID		 script = u_script.m_loc;
       ILxMessageID		 mess   = u_mess.m_loc;

       const char		*name, *hash;
       unsigned int		 size = 0;
       const char		*st;
       char			*localBuf, nameBuf[ 512 ];
       LxResult		 rc = LXe_OK;
       int			 error;
       int			 errMsg = -1;
       int			 numArgs = 0;

       Init();
       script[0]->GetBuffer( script, &st, &size );
       size -= 1;	// Remove the \0 from the buffer length

       /* Variable initialization */
       scriptSrv          = (ILxScriptSysServiceID)lx::GetGlobal(LXu_SCRIPTSYSSERVICE);
       dlgSrv             = (ILxStdDialogServiceID)lx::GetGlobal (LXu_STDDIALOGSERVICE);
       intrCur->script    = script;
       intrCur->execFlags = execFlags;

       /* Load up the default libraries */

       /*
        * Updated for Lua 5.1, per the Lua API Programming FAQ:
        *
        * http://lua-users.org/wiki/LuaFaq
        *
        * See "Why do I get a 'no calling environment' error?"
        */
       luaL_openlibs(L);

       /* Log Setup */
       if( LXx_FAIL( script[0]->UserName( script, &name ) ) )
               script[0]->Hash( script, &name );

       sprintf( nameBuf, "%s   (lua script)", name );
       logSvc.NewEntry( LXe_INFO, nameBuf, intrCur->log );

       if( intrTop == 0 ) {
               /* Add the entry to the subsystem */
               CLxLoc_Log	 logSubSys;
               logSvc.GetSubSystem( LXsLOG_SCRIPTSYS, logSubSys );

               logSubSys.AddEntry( ILxUnknownID(intrCur->log) );

       } else {
               /* Add the entry to the parent script's entry */
               intrStack[ intrTop - 1 ].log.AddEntry (intrCur->log);
       }

       /* Load the script into the interpreter */
       error = luaL_loadbuffer(L, st, strlen(st), "lua script");
       if( error ) {
               errMsg = 1;
       } else {
               /* Create the argument table */
               lua_newtable(L);		// arg table

               /* Push the script name onto the table at index 0 */
               script[0]->Hash( script, &hash );

               lua_pushnumber(L, 0);
               lua_pushstring(L, hash);
               lua_settable(L, -3);

               /* Parse the arguments and add them to the table */
               if (args) {
                       int alen = static_cast<int>(strlen (args)) + 1;
                       localBuf = new char [alen];
                       strcpy (localBuf, args);

                       char	*arg = localBuf;
                       char	*endQuote;

                       int	 index = 0;

                       while( (arg != NULL) && (arg[0] != '\0') ) {
                               /* Skip white space */
                               for( /*NULL*/; isspace( arg[0] ) && (arg[0] != '\0'); arg++ ) { ; }

                               if( arg[0] == '\0' )
                                       break;

                               /* Check for quoted arguments */
                               if( arg[0] == '\"' ) {
                                       arg++;
                                       endQuote = strchr( arg, '\"' );
                                       if( endQuote == NULL ) {
                                               /* Unbalanced quotes; fail */
                                               rc = LXe_FAILED;

                                               mess[0]->SetCode           (mess, rc);
                                               mess[0]->SetMessage        (mess, "lualintr", NULL, 3);
                                               mess[0]->SetArgumentString (mess, 1, args);

                                               error  = 1;
                                               errMsg = 2;
                                               break;
                                       }

                                       endQuote[0] = '\0';

                                       lua_pushnumber(L, ++index);
                                       lua_pushstring(L, arg);
                                       lua_settable(L, -3);

                                       numArgs++;

                                       arg = endQuote + 1;

                               } else {
                                       /* Normal space delimiting */
                                       endQuote = strchr( arg, ' ' );
                                       if( endQuote )
                                               endQuote[0] = '\0';

                                       lua_pushnumber(L, ++index);
                                       lua_pushstring(L, arg);
                                       lua_settable(L, -3);
                                       numArgs++;

                                       if( endQuote == NULL )
                                               arg = NULL;
                                       else
                                               arg = endQuote + 1;
                               }
                       }
               }

               /* Make the table into the global "arg" variable */
               lua_setglobal(L, "arg");

               if( !error ) {
                       /* Execute */
                       error = lua_pcall(L, 0, 0, 0);
                       if( error )
                               errMsg = 2;
               }
       }

       if( (errMsg == 1) || (errMsg == 2) ) {
               /* Error Handling */
               const char	*c = lua_tostring(L, -1);

               LogString( c, LXe_FAILED, 0 );
               lua_pop(L, 1);

               rc = LXe_FAILED;

               // TODO:  Figure out how to handle aborts differently from failures

               mess[0]->SetCode(           mess, rc );
               mess[0]->SetMessage(        mess, "luaintr", NULL, errMsg );
               mess[0]->SetArgumentString( mess, 1, c );
       }

       /* Clean Up */
       if (args)
               delete[] localBuf;

       Kill();

       return rc;
}  

performs most of the work, is the function that actually interprets the file.

       void
CLuaInterpreter::Kill()
{
       lua_close(L);

       /* Clean up our level of the stack */
       intrCur->script    = NULL;
       intrCur->rc        = LXe_OK;
       intrCur->tracing   = 0;
       intrCur->execFlags = LXfCMD_EXEC_DEFAULT;

       if( intrCur->askedForMonitor ) {
               dlgSrv[0]->MonitorRelease( dlgSrv );

               intrCur->askedForMonitor = 0;
               intrCur->monitor         = NULL;
       }

       assert( intrTop >= -1 );

       /* Set the current pointer to the previous level */
       intrTop--;
       intrCur = (intrTop == -1) ? NULL : &intrStack[ intrTop ];

}

This function cleans up.