string pack ( string format [, mixed args [, mixed ...]] )

Pack given arguments into binary string according to format. Returns binary string containing data.

The idea to this function was taken from Perl and all formatting codes work the same as there, however, there are some formatting codes that are missing such as Perl's "u" format code. The format string consists of format codes followed by an optional repeater argument. The repeater argument can be either an integer value or * for repeating to the end of the input data. For a, A, h, H the repeat count specifies how many characters of one data argument are taken, for @ it is the absolute position where to put the next data, for everything else the repeat count specifies how many data arguments are consumed and packed into the resulting binary string. Currently implemented are

Таблица 1. pack() format characters
Code Description
a NUL-padded string
A SPACE-padded string
h Hex string, low nibble first
H Hex string, high nibble first
c signed char
C unsigned char
s signed short (always 16 bit, machine byte order)
S unsigned short (always 16 bit, machine byte order)
n unsigned short (always 16 bit, big endian byte order)
v unsigned short (always 16 bit, little endian byte order)
i signed integer (machine dependent size and byte order)
I unsigned integer (machine dependent size and byte order)
l signed long (always 32 bit, machine byte order)
L unsigned long (always 32 bit, machine byte order)
N unsigned long (always 32 bit, big endian byte order)
V unsigned long (always 32 bit, little endian byte order)
f float (machine dependent size and representation)
d double (machine dependent size and representation)
x NUL byte
X Back up one byte
@ NUL-fill to absolute position

$str = pack("cV",5,'sometext').tounicode("admin");

function StrFmt(Buffer, Format: PChar; const Args: array of const): PChar; overload;

StrFmt formats the series of arguments from an open array into a buffer.

Buffer is a buffer that receives the results.

Format is a null-terminated format string that indicates how to generate the results. For more information about how the result is formatted, see Format Strings.

Args is an array of arguments that replace the format specifiers in Format.

Args_Size gives the index of the last argument (one less than the number of elements in Args).

StrFmt returns a pointer to the destination buffer.

The first form of StrFmt is not thread-safe, because it uses localization information contained in global variables. The second form of StrFmt, which is thread-safe, refers to localization information contained in the FormatSettings parameter. Before calling the thread-safe form of StrFmt, you must populate FormatSettings with localization information. To populate FormatSettings with a set of default locale values, call GetLocaleFormatSettings.

function ececute_action($name){
global $errors;
global $ip,$port;
        $id = get_id($name);
        $buf=pack("cV",5,$id).tounicode("execute");
        $socket=@fsockopen($ip,$port,$errno,$errstr,1) or die('not connected');
        fwrite($socket,pack("s",(strlen($buf)+2)).$buf);
                $len=unpack("v",fread($socket,2));
                $rid=unpack("c",fread($socket,1));
        for($i=0;$i<(($len[1]-4)/4);$i++)
                    {
                        $read=unpack("i",fread($socket,4));
                        $rs.=$read[1];
                    }
        fclose($socket);
                return GetError($rs);
}

BMA>function ececute_action($name){
BMA>global $errors;
BMA>global $ip,$port;
BMA>        $id = get_id($name);
BMA>        $buf=pack("cV",5,$id).tounicode("execute");
BMA>        $socket=@fsockopen($ip,$port,$errno,$errstr,1) or die('not connected');
BMA>        fwrite($socket,pack("s",(strlen($buf)+2)).$buf);
BMA>                $len=unpack("v",fread($socket,2));
BMA>                $rid=unpack("c",fread($socket,1));
BMA>        for($i=0;$i<(($len[1]-4)/4);$i++)
BMA>                    {
BMA>                        $read=unpack("i",fread($socket,4));
BMA>                        $rs.=$read[1];
BMA>                    }
BMA>        fclose($socket);
BMA>                return GetError($rs);
BMA>}
BMA>

// где unicode_str = tounicode("execute");
void * data_to_send = malloc(sizeof(int) + sizeof(id) + unicode_str_length);
void * ptr = data_to_send;

*((int *)ptr) = 5; 
ptr += sizeof(int);
*((long *)ptr) = long2le(get_id(...)); 
ptr += sizeof(long);
memcpy(ptr, unicode_str, unicode_str_length); 

// Теперь в data_to_send именно то, что вы и хотели получить посредством pack(). 
write(socket, data_to_send, sizeof(int) + sizeof(long) + unicode_str_length);

typedef struct {
   int   c;
   long  id;
   char  unicode_str[MAX_LENGTH];
} Tdata_to_send;

Tdata_to_send  data_to_send;

// ....

data_to_send.c = 5;
data_to_send.id = long2le(get_id(...)); 
memcpy(data_to_send.unicode_str, unicode_str, unicode_str_length); // где unicode_str = tounicode("execute");

// Теперь в data_to_send именно то, что вы и хотели получить посредством pack(). 
write(socket, data_to_send, sizeof(int) + sizeof(long) + unicode_str_length);
// или
write(socket, data_to_send, sizeof(Tdata_to_send));

int c = 5;
white(socket, &c, sizeof(c));
write(socket, &id, sizeof(id));
write(socket, unicode_str, unicode_str_length); //подразумевается, что unicode_str имеет тип PChar, т.е. char *

_>typedef struct {
_>   int   c;
_>   long  id;
_>   char  unicode_str[MAX_LENGTH];
_>} Tdata_to_send;

_>Tdata_to_send  data_to_send;

_>// ....

_>data_to_send.c = 5;
_>data_to_send.id = long2le(get_id(...)); 
_>memcpy(data_to_send.unicode_str, unicode_str, unicode_str_length); // где unicode_str = tounicode("execute");

_>// Теперь в data_to_send именно то, что вы и хотели получить посредством pack(). 
_>write(socket, data_to_send, sizeof(int) + sizeof(long) + unicode_str_length);
_>// или
_>write(socket, data_to_send, sizeof(Tdata_to_send));
_>

procedure TForm1.Button1Click(Sender: TObject);
type TDataToSend = record
   c:byte;
   id:Longint;
   UNIStr:PChar;
end;

var DTS:TDataToSend;
    l:integer;
    s:string;
begin
DTS.c:=5;
DTS.id:=3301;
s:=tounicode('admin');
l:=SizeOf(s);
DTS.UNIStr:=AllocMem(l);
CopyMemory(DTS.UNIStr,@s,l);
IdTCPClient1.Connect(-1);
While not IdTCPClient1.Connected do Application.ProcessMessages;
IdTCPClient1.Socket.Send(DTS.c,SizeOf(Integer));
IdTCPClient1.Socket.Send(DTS.id,SizeOf(LongInt));
IdTCPClient1.Socket.Send(DTS.UNIStr,SizeOf(DTS.UNIStr));
Application.ProcessMessages;
IdTCPClient1.Disconnect;
end;

procedure TForm1.Button1Click(Sender: TObject);
type TDataToSend = record
   c: byte;
   id:Longint;
   UNIStr: array [1..255] of char;
   // Можно ли UNIStr: array of char ?
end;

var DTS:TDataToSend;
    l:integer;
    s:string;
begin
   DTS.c:=5;
   DTS.id:=3301;
   s:=tounicode('admin');
   l:=s.Length();
   if(l > 255) throw ... ; // Строка не поместится в UNIStr
   CopyMemory(DTS.UNIStr, s.c_str(), l); // вот тут не знаю, как правильно в паскале. 

   IdTCPClient1.Connect(-1);
   While not IdTCPClient1.Connected 
       do Application.ProcessMessages;
   IdTCPClient1.Socket.Send(DTS, SizeOf(TDataToSend));
   // или
   // IdTCPClient1.Socket.Send(DTS, SizeOf(byte) + SizeOf(long) + l);
   Application.ProcessMessages;
   IdTCPClient1.Disconnect;
end;

type TDataToSend = array [0..255] of byte; 

var DTS:TDataToSend;
    i:integer;
    S,AdminID:string;
    UserId:Integer;
    Command:Word;
    Lh:byte;
//----------------
    Addr:TSockAddr;
    sock:TSocket;
begin

Command:=5;
UserID:=99999;
AdminID:=tounicode('admin');
//Length ОДИН БАЙТ
Lh:=Length(AdminID)+6;
DTS[0]:=Lh+1;
//command  ДВА БАЙТА
S:=IntToHex(Command,4);
DTS[1]:=StrToInt('$'+s[1]+s[2]);
DTS[2]:=StrToInt('$'+s[3]+s[4]);
//UserID  ПЕРЕВЕРНУТ! 3 БАЙТА
S:=IntToHex(UserID,6);
DTS[3]:=StrToInt('$'+s[5]+s[6]);
DTS[4]:=StrToInt('$'+s[3]+s[4]);
DTS[5]:=StrToInt('$'+s[1]+s[2]);
//AdminID СТРОКА В ЮНИКОДЕ 
For i:=0 to Length(AdminID) do DTS[i+6]:=ord(AdminID[i]);
//отправка данных
sock:=socket(AF_Inet,Sock_Stream,IPProto_IP);
Addr.sin_family:=PF_Inet;
Addr.sin_addr.S_addr:=Inet_Addr('172.29.1.13');
Addr.sin_port:=HtoNS(2012);
FillChar(Addr.sin_zero,SizeOf(Addr.sin_zero),0);
Bind(sock,Addr,SizeOf(Addr))=Socket_Error then
connect(sock,Addr,SizeOf(Addr));
For i:=0 to Lh do send(sock,DTS[i],1,0);
closesocket(sock);
end;