LibRPC

Library used to execute functions or script send from server. For remotely executing functions of npcscripts from server, see function RFC available with plugin npc04relxx. For executing functions of server from npcscripts, continue reading.

Calling Functions of VCMP Server

From v1.6 beta 4 and rpclib(API 1.2) onwards, npc can remotely execute functions of server, provided the server runs squirrel gamemode and player.IsAdmin=true for npc.

//npcscripts
RFC("SetWeather")(5);
RFC("SetHour")(12);
RFC("SetDriveOnWater")(true);

The following functions are added to npcscripts:

• F
• RFC (click to see more complicated examples)
• Fa
• RFCa
• Z (get)
• S (set)

ServerData Identifier

LibRPC when loaded works on server data whose first four bytes is the following:

Offset	Type	Value
0	Integer	0x40000000

ServerData structure

Offset	Type	Value
4	Character	'F' or 'G'	Function

Function structure

'F' type function

print(500)

F type functions are those functions to be called through a name, ( unlike to be called through other methods see 'G' type functions ). The function name is encoded from offset 7.

Offset^	Type	Value
0	Character	'F'
1-4	Unsigned Integer	size of the function buffer
5-6	unsigned short	length of the function name
7 - 7+len(funcname)-1	characters	Function Name
7+len - ...	...	...

^Offset relative to this buffer and not relative to ServerData ( complete buffer. )

'G' type function

compilestring("print(500)")()  //--second order

G type functions (The name G because character F already taken ). They are functions returned by another function. So the buffer of the G type function contain another function which is first called and its return value, if it is a function, is then called. They can be said to be second order functions.

Offset^	Type	Value
0	Character	'G'
1-4	Unsigned Integer	size of the buffer
5	Character	'G' or 'F'
...	...	...

^Offset relative to 'G' function buffer and not relative to complete buffer of ServerData. Functions of higher order can be called through this method.

Example

Offset	Value	Explanation
0-3	00 00 00 40	0x40000000
4	46	F
5-8	00 00 00 0f	len of func buffer
9-10	00 05	len of func name (11-15)
11-15	70 72 69 6e 74	p r i n t
16	73	s (for string)
17	00 05	len of string (19-23)
19-23	48 65 6c 6c 6f	H e l l o

Other structures

String

Offset^	Type	Value
0	char	's'
1-2	unsigned short	len of string
3 - 3+len of string-1	char sequence	the string

Integers

Offset^	Type	Value
0	char	'i'
1-4	int	integer

Float

Offset^	Type	Value
0	char	'f'
1-4	float	floating point number

null

Offset^	Type	Value
0	char	'o'

bool

Offset^	Type	Value
0	char	'b'
1	unsigned char	0 or 1

Vector

Offset^	Type	Value
0	char	'v'
1-4	float	Vector.x
5-8	float	Vector.y
9-12	float	Vector.z

Quaternion

Offset^	Type	Value
0	char	'q'
1-4	float	Quaternion.x
5-8	float	Quaternion.y
9-12	float	Quaternion.z
13-16	float	Quaternion.w

Arrays

Offset^	Type	Value
0	char	'a'
1-4	unsigned int	length of the array stream
5	char	...

^All Offsets relative to respective type buffers.

More added since API 1.4

'E' type function

E type functions are same as F type function with the exception that roottable will be the environment for the latter where as in 'E' type functions, any table( or class/instance) can be passed as environment by specifying its name as first parameter. On remote side, the sq_get of function name is performed after pushing first parameter and then if the resultant object is function, it is called with 'first parameter' as env.

Offset^	Type	Value
0	Character	'E'
1-4	Unsigned Integer	size of the function buffer
5-6	unsigned short	length of the function name
7 - 7+len(funcname)-1	characters	Function Name
7+len - ...	...	...

D type function

This is same as G type function with the exception that custom environment can be passed to the function.

Offset^	Type	Value
0	Character	'D'
1-4	Unsigned Integer	size of the buffer
5	Character	'G'/ 'F'/ 'E' or 'D'
...	...	...

^Offset relative to this buffer and not relative to ServerData ( complete buffer. )

'g' structure

Used for sq_get operation

Offset^	Type	Value
0	Character	'g'
1-4	Unsigned Integer	size of the buffer
...	...	...

'h' structure

Used for sq_set operation on remote vm. Unlike other structures, this one can be send independently with RPC_STREAM_IDENTIFIER

Offset^	Type	Value
0	Character	'h'
1-4	Unsigned Integer	size of the buffer
...	...	...

API Version

1.4 (June 2023)

Downloads

These are old versions(1.2). New ones are available with npcclient.

Operating system	bit	Link	Size	API
Windows		rpclib.dll	16 KB	1.2
Linux	x64	rpclib64.so	25.58 KB	1.2
Linux	x86	rpclib32.so	24.46 KB	1.2
Source	-	LibRPC-master.zip	18.65 KB	1.2

See Also

• Examples