Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

  • Congratulations strongm on being selected by the Tek-Tips community for having the most helpful posts in the forums last week. Way to Go!

Passing structures to external functions

Status
Not open for further replies.

gatorrob

Programmer
Apr 30, 2004
9
US
I have written an app in PB8 that makes calls to the Seagate Info 7 SDK. Using the SDK examples as a guide, I have managed to successfully perform the desired SDK functions. Unfortunately, the SDK does not appear to be receiving the values in my structures correctly. As a result, the functions perform the wrong action. Below is the documented code in C along with my implementation in PowerBuilder. Here are some observations. The first field of each structure stores the size of the structure. When I calculate the size manually (I count the full length of char fields), I get a number that is less than the documented length. My calculation is based on 2 bytes for int, unit; 4 bytes for long, ulong; n bytes for char[n]. The lengths of the char fields are always defined as n+1. Not sure if the "+1" is somehow significant. The SDK comes with Init functions for the structures which populate the first field (structsize). The value is always way less than even my manual calculation. I have tried setting the field lenghts to n, n+1, n+2. I have tried setting the structsize to my manual calculation as well as the documented length. Nothing seems to make a difference. I have run out of ideas and would appreciate any suggestions. The code below is of one of the simplier structures. I have structures with sub-structures as well, but I don't want to complicate the issue.

C Code:
#define CI_FOLDER_NAME_BUFFER_SIZE (50 + 1)
#define CI_FOLDER_DESC_BUFFER_SIZE (255 + 1)
#define CI_USER_NAME_BUFFER_SIZE (128 + 1)
typedef short CI_BOOL;
typedef unsigned long CI_SEC_ID;
typedef struct tagCIFolderInfo
{
DWORD StructSize; /* 456 bytes (32-bit), 450 bytes (16-bit) */
char Name [CI_FOLDER_NAME_BUFFER_SIZE];
char Desc [CI_FOLDER_DESC_BUFFER_SIZE];
CI_BOOL IsPrivate;
CI_SEC_ID ParentId;
CI_SEC_ID Id;
char Owner [CI_USER_NAME_BUFFER_SIZE]; /* Output of folder info getting */
} CIFOLDERINFO;
typedef CIFOLDERINFO FAR * LPCIFOLDERINFO;

PB code:
global type str_cifolderinfo from structure
unsignedlong structsize
character foldername[51]
character folderdesc[256]
integer isprivate
unsignedlong parentid
unsignedlong id
character owner[129]
end type

lstr_folderinfo.StructSize = 450
lstr_folderinfo.FolderName = "Test Folder"
lstr_folderinfo.FolderDesc = "This folder was created for testing purposes. Do not publish reports to this folder."
lstr_folderinfo.IsPrivate = 1
lstr_folderinfo.ParentId = nullulong




 
Status
Not open for further replies.

Part and Inventory Search

Sponsor

Back
Top