#DEFINE PAGE_READONLY 2
#DEFINE PAGE_READWRITE 4
#DEFINE PAGE_WRITECOPY 8
#DEFINE PAGE_EXECUTE_READ 0x20
#DEFINE PAGE_EXECUTE_READWRITE 0x40
 
#DEFINE SECTION_QUERY 1
#DEFINE SECTION_MAP_WRITE 2
#DEFINE SECTION_MAP_READ 4
#DEFINE SECTION_MAP_EXECUTE 8
#DEFINE SECTION_EXTEND_SIZE 0x10
#DEFINE STANDARD_RIGHTS_REQUIRED 0xF0000
 
#DEFINE SECTION_ALL_ACCESS BITOR(STANDARD_RIGHTS_REQUIRED,;
    SECTION_QUERY, SECTION_MAP_WRITE, SECTION_MAP_READ,;
    SECTION_MAP_EXECUTE, SECTION_EXTEND_SIZE)
 
#DEFINE FILE_MAP_WRITE SECTION_MAP_WRITE
#DEFINE FILE_MAP_READ SECTION_MAP_READ
#DEFINE FILE_MAP_ALL_ACCESS SECTION_ALL_ACCESS
 
#DEFINE INVALID_HANDLE_VALUE -1
#DEFINE MAX_PATH 260
 
DO declare
DO ScanDevices
 
PRIVATE cFilename, nError, nFileSize, nFileType, hFileIndex, hProcess
cFilename=""
STORE 0 TO nError
* obtain (pseudo) handle for the current process
hProcess=GetCurrentProcess()
 
* try to open a file using FoxPro low-level file functions
LOCAL hFile1
hFile1 = FOPEN("MYFILE.TXT", 2)
? "hFile1:", hFile1
 
CREATE CURSOR cs (hfile I, errorcode I, filename C(250),;
    filesize I, filetype I)
 
FOR hFileIndex=1 TO 4096
    nError=0
    cFilename=""
    nFileSize = GetFileSize(hFileIndex)
    nFileType = GetFileType(hFileIndex)
 
    * both modes should match, for example:
    * PAGE_READONLY, SECTION_MAP_READ
    * PAGE_READWRITE, SECTION_MAP_WRITE
    = GetName(hFileIndex, PAGE_READONLY, SECTION_MAP_READ)
 
    INSERT INTO cs VALUES (m.hFileIndex, m.nError,;
        m.cFilename, m.nFilesize, m.nFileType)
NEXT
 
IF hFile1 <> INVALID_HANDLE_VALUE
    = FCLOSE(hFile1)
ENDIF
 
BROWSE NORMAL FOR errorcode=0 NOWAIT
* end of main
 
PROCEDURE GetName(hFile, nCreateFlag, nMapFlag)
    LOCAL hFileMap, hMem, cBuffer, nBufsize
 
    hFileMap = CreateFileMapping(hFile, 0, nCreateFlag, 0,1, Null)
    IF hFileMap <= 0
        nError=GetLastError()
        RETURN
    ENDIF
 
    hMem = MapViewOfFile(hFileMap, nMapFlag, 0,0,1)
    IF hMem = 0
        nError=GetLastError()
        cBuffer=""
    ELSE
        cBuffer = REPLICATE(CHR(0), MAX_PATH)
        nBufsize = GetMappedFileName(hProcess, hMem,;
            @cBuffer, MAX_PATH)
 
        IF nBufsize=0
            nError=GetLastError()
            cBuffer=""
        ELSE
            cBuffer = SUBSTR(cBuffer, 1, nBufsize)
        ENDIF
        = UnmapViewOfFile(hMem)
    ENDIF
    CloseHandle(hFileMap)
    cFilename=cBuffer
 
FUNCTION GetFileSize(hFile)
#DEFINE MAX_DWORD 0xffffffff
    LOCAL cBuffer
    cBuffer = REPLICATE(CHR(0), 8)
    IF GetFileSizeEx(hFile, @cBuffer) = 0
        RETURN 0
    ELSE
        RETURN buf2dword(SUBSTR(cBuffer,1,4)) +;
                buf2dword(SUBSTR(cBuffer,5,4)) * (MAX_DWORD+1)
    ENDIF
 
PROCEDURE ScanDevices
    CREATE CURSOR csDosDevices (drvletter C(2), targetpath C(250))
 
    LOCAL cDrives, nBufsize, cDrvLetter, ch, cTargetPath
    cDrives = REPLICATE(CHR(0), 250)
    nBufsize = GetLogicalDriveStrings(LEN(cDrives), @cDrives)
    cDrives = PADR(cDrives, nBufsize)
 
    cDrvLetter=""
    FOR nBufsize=1 TO LEN(cDrives)
        ch = SUBSTR(cDrives, nBufsize,1)
        IF ch = Chr(0)
            cDrvLetter=PADR(cDrvLetter,2)
            cTargetPath = REPLICATE(CHR(0), MAX_PATH)
 
            = QueryDosDevice(cDrvLetter, @cTargetPath,;
                LEN(cTargetPath))
 
            cTargetPath = STRTRAN(cTargetPath, CHR(0), "")
            INSERT INTO csDosDevices VALUES (;
                cDrvLetter, cTargetPath)
 
            cDrvLetter = ""
        ELSE
            cDrvLetter = cDrvLetter + m.ch
        ENDIF
    NEXT
 
PROCEDURE declare
    DECLARE INTEGER CloseHandle IN kernel32 INTEGER hObject
    DECLARE INTEGER GetLastError IN kernel32
    DECLARE INTEGER GetFileType IN kernel32 INTEGER hFile
    DECLARE INTEGER GetFileSizeEx IN kernel32;
        INTEGER hFile, STRING @lpFileSize
 
    DECLARE INTEGER CreateFileMapping IN kernel32;
        INTEGER hFile, INTEGER lpAttributes, INTEGER flProtect,;
        LONG dwMaximumSizeHi, LONG dwMaximumSizeLo, STRING lpName
 
    DECLARE LONG MapViewOfFile IN kernel32;
        INTEGER hFileMappingObject, INTEGER dwDesiredAccess,;
        LONG dwFileOffsetHi, LONG dwFileOffsetLo,;
        LONG dwNumberOfBytesToMap
 
    DECLARE INTEGER UnmapViewOfFile IN kernel32 LONG lpBaseAddress
    DECLARE INTEGER GetCurrentProcess IN kernel32
 
    DECLARE INTEGER GetMappedFileName IN psapi;
        INTEGER hProcess, INTEGER lpv,;
        STRING @lpFilename, INTEGER nSize
 
    DECLARE INTEGER OpenFile IN kernel32;
        STRING lpFileName, STRING @lpReOpenBuff, INTEGER wStyle 
 
    DECLARE INTEGER GetLogicalDriveStrings IN kernel32;
        INTEGER nBufferLength, STRING @lpBuffer
 
    DECLARE INTEGER QueryDosDevice IN kernel32;
        STRING lpDeviceName, STRING @lpTargetPath, LONG ucchMax
 
FUNCTION buf2dword(lcBuffer)
RETURN Asc(SUBSTR(lcBuffer, 1,1)) + ;
    BitLShift(Asc(SUBSTR(lcBuffer, 2,1)),  8) +;
    BitLShift(Asc(SUBSTR(lcBuffer, 3,1)), 16) +;
    BitLShift(Asc(SUBSTR(lcBuffer, 4,1)), 24)