Bad file descriptor message when creating compressed file with gzip.exe on Windows, using Visual FoxPro9 and WINAPI functions

What i'm trying to do is write text to gzip.exe StdIn and redirect its StdOut to a file, all this using WINAPI functions and visual Foxpro 9.

The problem is that I always get "Stdin: Bad file descriptor" error and no output. What I expect to have is the file associated with StdOut filled with data and the file associated with StdErr empty. Instead I always endup with the file associated with StdOut empty and the file associated with StdErr filled with:

standard input: Bad file descriptor gzip:"

Here is my code:

*----------------------------------------------------------------


LOCAL cBuffer, nBytesRead, newBufSize, nBytesWritten

LOCAL hReadPipe, hWritePipe, res, cSecAttr, cFile, hFile, process_info, start_info, hProcess, hThread

*---------------------------------------------------

#DEFINE BUFF_SIZE 1024

#DEFINE WAIT_TIMEOUT 0x00000102

#DEFINE WAIT_INTERVAL 5000

#DEFINE INFINITE 0xFFFFFFFF

*---------------------------------------------------

#DEFINE HANDLE_FLAG_INHERIT 0x00000001
*---------------------------------------------------

#DEFINE FILE_APPEND_DATA 4

#DEFINE FILE_SHARE_READ 0x00000001

#DEFINE FILE_SHARE_WRITE 0x00000002

#DEFINE CREATE_ALWAYS 2

#DEFINE FILE_ATTRIBUTE_NORMAL 0x80

#DEFINE INVALID_HANDLE_VALUE -1

#DEFINE GENERIC_READ 0x80000000

#DEFINE GENERIC_WRITE 0x40000000

*---------------------------------------------------

#DEFINE STARTF_USESTDHANDLES 0x00000100

#DEFINE STARTF_USESHOWWINDOW 0x00000001

#DEFINE CREATE_NO_WINDOW 0x08000000

*---------------------------------------------------

DECLARE INTEGER WaitForSingleObject IN kernel32.DLL ;

             INTEGER hHandle, ;

             INTEGER dwMilliseconds 
DECLARE INTEGER GetLastError IN kernel32.DLL

DECLARE INTEGER CloseHandle IN kernel32.DLL INTEGER hObject

DECLARE INTEGER CreatePipe IN kernel32;

             INTEGER @ hReadPipe, ;

             INTEGER @ hWritePipe, ;

              STRING @ lpPipeAttributes, ;

                LONG   nSize 
DECLARE INTEGER SetHandleInformation IN Kernel32 ;

             INTEGER hObject, ;

                LONG dwMask, ;

                LONG dwFlags 
DECLARE INTEGER ReadFile IN kernel32 ;

             INTEGER   hFile, ;

              STRING @ lpBuffer, ;

             INTEGER   nNumberOfBytesToRead, ;


             INTEGER @ lpNumberOfBytesRead, ;

             INTEGER   lpOverlapped 
DECLARE INTEGER WriteFile IN Kernel32 ;

             INTEGER hFile, ;

             STRING lpBuffer, ;

             INTEGER nBt2Write, ;

             INTEGER @ lpBtWritten, ;

             INTEGER lpOverlapped  
DECLARE INTEGER CreateFile IN Kernel32.DLL ;

             STRING lpFileName, ;

            INTEGER dwDesiredAccess, ;

            INTEGER dwShareMode, ; 

             STRING lpSecurityAttributes, ;

            INTEGER dwCreationDisposition, ;

            INTEGER dwFlagsAndAttributes, ;

            INTEGER hTemplateFile 
DECLARE INTEGER CreateProcess IN kernel32.DLL ;

            INTEGER lpApplicationName, ;

             STRING lpCommandLine, ;

            INTEGER lpProcessAttributes, ;

            INTEGER lpThreadAttributes, ;

            INTEGER bInheritHandles, ;

            INTEGER dwCreationFlags, ;

            INTEGER lpEnvironment, ;

            INTEGER lpCurrentDirectory, ;

             STRING @lpStartupInfo, ;

             STRING @lpProcessInformation  
*-------------------------------------------------------

hReadPipe=0

hWritePipe=0

cSecAttr=BINTOC(12,'4RS')+BINTOC(0,'4RS')+BINTOC(1,'4RS')

res=CreatePipe(@hReadPipe,@hWritePipe,cSecAttr,BUFF_SIZE)

res=SetHandleInformation(hReadPipe, HANDLE_FLAG_INHERIT,0)

res=SetHandleInformation(hWritePipe, HANDLE_FLAG_INHERIT,0)

*-------------------------------------------------------

cSecAttr=BINTOC(12,'4RS')+BINTOC(0,'4RS')+BINTOC(1,'4RS')

cFile="d:\ggzz.sql.gz"

hFile=0
hFile=CreateFile(cFile,BITOR(GENERIC_READ,GENERIC_WRITE),BITOR(FILE_SHARE_READ,FILE_SHARE_WRITE),cSecAttr,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0)

*-------------------------------------------------------

cSecAttr=BINTOC(12,'4RS')+BINTOC(0,'4RS')+BINTOC(1,'4RS')

cFile="d:\gzip.err"

hGzipErr=0

hGzipErr=CreateFile(cFile,BITOR(GENERIC_READ,GENERIC_WRITE),BITOR(FILE_SHARE_READ,FILE_SHARE_WRITE),cSecAttr,CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL,0)

*-------------------------------------------------------

cKmd="d:\gzip\bin\gzip.exe"

process_info = REPLICATE(CHR(0), 16)

start_info = BINTOC(68,'4RS') + REPLICATE(CHR(0), 64) start_info=LEFT(start_info,44)+BINTOC(BITOR(STARTF_USESTDHANDLES,STARTF_USESHOWWINDOW),'4RS')+REPLICATE(CHR(0), 20)

start_info=LEFT(start_info,56)+BINTOC(hReadPipe,'4RS')+BINTOC(hFile,'4RS')+BINTOC(hGzipErr,'4RS')

res = CreateProcess(0,cKmd, 0, 0, 1, 0, 0, 0, @start_info, @process_info)

hProcess=CTOBIN(SUBSTR(process_info, 1, 4),'4RS')

hThread=CTOBIN(SUBSTR(process_info, 5, 4),'4RS')

DIMENSION aaa(3)

aaa(1)="11111111111111111111111"

aaa(2)="222222222222222222222222"

aaa(3)="3333333333333333333333"

FOR i=1 TO ALEN(aaa)

  cBuffer=aaa(i)

  newBufsize=LEN(cBuffer)

  nBytesWritten=0

  res=WriteFile(hWritePipe,cBuffer,newBufsize,@nBytesWritten,0)

  IF nBytesWritten=0

     EXIT 

  ENDIF 
ENDFOR

=WaitForSingleObject(hProcess,INFINITE)

res=CloseHandle(hFile)

res=CloseHandle(hThread)

res=CloseHandle(hProcess)

res=CloseHandle(hReadPipe)

res=CloseHandle(hWritePipe)

CLEAR DLLS "CreatePipe","GetLastError", "CreateFile", "CreateProcess", "CloseHandle","SetHandleInformation", ; "ReadFile", "WriteFile"