Consultor Eletrônico

Status: Unverified

GOAL:

How to get the HostName from a Windows Client through 4GL

FACT(s) (Environment):

Windows NT 32 Intel/Windows 2000

FIX:

&SCOPED-DEFINE WSADESCRIPTION_LEN 256
&SCOPED-DEFINE WSASYS_STATUS_LEN 128

&SCOPED-DEFINE WSADATA_VERSION_LOW 1 /* WORD(2) */
&SCOPED-DEFINE WSADATA_VERSION_HIGH 3 /* WORD(2) */
&SCOPED-DEFINE WSADATA_DESCRIPTION 5 /*
CHAR(WSADESCRIPTION_LEN + 1)
*/
&SCOPED-DEFINE WSADATA_SYSTEM_STATUS 262 /* CHAR(WSASYS_STATUS_LEN
+ 1)
*/
&SCOPED-DEFINE WSADATA_MAX_SOCKETS 391 /* SHORT(4) */
&SCOPED-DEFINE WSADATA_MAX_UDP 395 /* SHORT(4) */
&SCOPED-DEFINE WSADATA_VENDOR_INFO 399 /* CHAR*(4) */
&SCOPED-DEFINE WSADATA_LENGTH 403

&SCOPED-DEFINE HOSTENT_NAME 1 /* CHAR*(4) */
&SCOPED-DEFINE HOSTENT_ALIASES 5 /* CHAR**(4) */
&SCOPED-DEFINE HOSTENT_ADDR_TYPE 9 /* SHORT(2) */
&SCOPED-DEFINE HOSTENT_ADDR_LENGTH 11 /* SHORT(2) */
&SCOPED-DEFINE HOSTENT_ADDR_LIST 13 /* CHAR**(4) */
&SCOPED-DEFINE HOSTENT_LENGTH 16


PROCEDURE i-GetTcpInfo:
/*------------------------------------------------------------------------
Procedure : i-GetTcpInfo

Description : Return the windows TCP host name and address of this PC.

Parms : - Host name. (OUTPUT, CHARACTER)
- Host address. (OUTPUT, CHARACTER):

Sample usage: RUN i-GetTcpInfo (OUTPUT w-TcpName,
OUTPUT w-TcpAddr).

Notes : -
------------------------------------------------------------------------*/
DEFINE OUTPUT PARAMETER p-TcpName AS CHARACTER NO-UNDO.
DEFINE OUTPUT PARAMETER p-TcpAddr AS CHARACTER NO-UNDO.

DEFINE VARIABLE w-TcpName AS CHARACTER NO-UNDO.
DEFINE VARIABLE w-Length AS INTEGER NO-UNDO.
DEFINE VARIABLE w-Return AS INTEGER NO-UNDO.
DEFINE VARIABLE ptr-WsaData AS MEMPTR NO-UNDO.
DEFINE VARIABLE w-Hostent AS INTEGER NO-UNDO.
DEFINE VARIABLE ptr-Hostent AS MEMPTR NO-UNDO.
DEFINE VARIABLE ptr-AddrString AS MEMPTR NO-UNDO.
DEFINE VARIABLE ptr-AddrList AS MEMPTR NO-UNDO.
DEFINE VARIABLE ptr-ListEntry AS MEMPTR NO-UNDO.
DEFINE VARIABLE w-TcpLong AS INTEGER NO-UNDO.

/* Initialize return values */
ASSIGN p-TcpName = ?
p-TcpAddr = ?
.

/* Allocate work structure for WSADATA */
SET-SIZE(ptr-WsaData) = {&WSADATA_LENGTH}.

/* Ask Win32 for winsock usage */
RUN WSAStartup (INPUT 257, /* requested version 1.1 */
INPUT GET-POINTER-VALUE(ptr-WsaData),
OUTPUT w-Return).

/* Release allocated memory */
SET-SIZE(ptr-WsaData) = 0.

/* Check for errors */
IF w-Return NE 0 THEN DO:
MESSAGE "Error accessing WINSOCK support." VIEW-AS ALERT-BOX.
RETURN.
END.

/* Set up variables */
ASSIGN w-Length = 100
w-TcpName = FILL(" ", w-Length)
.

/* Call Win32 routine to get host name */
RUN gethostname (OUTPUT w-TcpName,
INPUT w-Length,
OUTPUT w-Return).

/* Check for errors */
IF w-Return NE 0 THEN DO:
MESSAGE "Error getting tcp name." VIEW-AS ALERT-BOX.
RUN WSACleanup (OUTPUT w-Return).
RETURN.
END.

/* Pass back gathered info */
/* remember: the string is null-terminated so there is a CHR(0)
inside w-TcpName. We have to trim it: */
p-TcpName = ENTRY(1,w-TcpName,CHR(0)).

/* Call Win32 routine to get host address */
RUN gethostbyname (INPUT w-TcpName,
OUTPUT w-Hostent).

/* Check for errors */
IF w-Hostent EQ 0 THEN DO:
MESSAGE "Error resolving host name." VIEW-AS ALERT-BOX.
RUN WSACleanup (OUTPUT w-Return).
RETURN.
END.

/* Set pointer to HostEnt data structure */
SET-POINTER-VALUE(ptr-Hostent) = w-Hostent.

. /* "Chase" pointers to get to first address list entry */
SET-POINTER-VALUE(ptr-AddrList) = GET-LONG(ptr-Hostent,
{&HOSTENT_ADDR_LIST}).
SET-POINTER-VALUE(ptr-ListEntry) = GET-LONG(ptr-AddrList, 1).
w-TcpLong = GET-LONG(ptr-ListEntry, 1).

RUN inet_ntoa (INPUT w-TcpLong,
OUTPUT ptr-AddrString).

/* Pass back gathered info */
p-TcpAddr = GET-STRING(ptr-AddrString, 1).

/* Terminate winsock usage */
RUN WSACleanup (OUTPUT w-Return).

END PROCEDURE.

PROCEDURE gethostname EXTERNAL "wsock32.dll" :
DEFINE OUTPUT PARAMETER p-Hostname AS CHARACTER.
DEFINE INPUT PARAMETER p-Length AS LONG.
DEFINE RETURN PARAMETER p-Return AS LONG.
END PROCEDURE.

PROCEDURE gethostbyname EXTERNAL "wsock32.dll" :
DEFINE INPUT PARAMETER p-Name AS CHARACTER.
DEFINE RETURN PARAMETER p-Hostent AS LONG.
END PROCEDURE.

PROCEDURE inet_ntoa EXTERNAL "wsock32.dll" :
DEFINE INPUT PARAMETER p-AddrStruct AS LONG.
DEFINE RETURN PARAMETER p-AddrString AS MEMPTR.
END PROCEDURE.

PROCEDURE WSAStartup EXTERNAL "wsock32.dll" :
DEFINE INPUT PARAMETER p-VersionReq AS SHORT.
DEFINE INPUT PARAMETER ptr-WsaData AS LONG.
DEFINE RETURN PARAMETER p-Return AS LONG.
END PROCEDURE.

PROCEDURE WSACleanup EXTERNAL "wsock32":
DEFINE RETURN PARAMETER p-Return AS LONG.
END PROCEDURE.


DEF VAR my_tcpname AS CHAR NO-UNDO.
DEF VAR my_tcpipad AS CHAR NO-UNDO.

RUN i-GetTCPInfo(OUTPUT my_tcpname, OUTPUT my_tcpipad).

MESSAGE my_tcpname my_tcpipad VIEW-AS ALERT-BOX..