/******************************************************************************

Module: FileRev.cpp

Notices: Copyright (c) 2000 Jeffrey Richter

******************************************************************************/

#include "..\CmnHdr.h" /* See Appendix A. */

#include <windowsx.h>

#include <tchar.h>

#include <commdlg.h>

#include <string.h> // For _strrev

#include "Resource.h"

///////////////////////////////////////////////////////////////////////////////

#define FILENAME TEXT("FILEREV.DAT")

///////////////////////////////////////////////////////////////////////////////

BOOL FileReverse(PCTSTR pszPathname, PBOOL pfIsTextUnicode) {

*pfIsTextUnicode = FALSE; // Assume text is Unicode

// Open the file for reading and writing.

HANDLE hFile = CreateFile(pszPathname, GENERIC_WRITE | GENERIC_READ, 0,

NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);

if (hFile == INVALID_HANDLE_VALUE) {

chMB("File could not be opened.");

return(FALSE);

}

// Get the size of the file (I assume the whole file can be mapped).

DWORD dwFileSize = GetFileSize(hFile, NULL);

// Create the file-mapping object. The file-mapping object is 1 character

// bigger than the file size so that a zero character can be placed at the

// end of the file to terminate the string (file). Because I don't yet know

// if the file contains ANSI or Unicode characters, I assume worst case

// and add the size of a WCHAR instead of CHAR.

HANDLE hFileMap = CreateFileMapping(hFile, NULL, PAGE_READWRITE,

0, dwFileSize + sizeof(WCHAR), NULL);

if (hFileMap == NULL) {

chMB("File map could not be opened.");

CloseHandle(hFile);

return(FALSE);

}

// Get the address where the first byte of the file is mapped into memory.

PVOID pvFile = MapViewOfFile(hFileMap, FILE_MAP_WRITE, 0, 0, 0);

if (pvFile == NULL) {

chMB("Could not map view of file.");

CloseHandle(hFileMap);

CloseHandle(hFile);

return(FALSE);

}

// Does the buffer contain ANSI or Unicode?

int iUnicodeTestFlags = -1; // Try all tests

*pfIsTextUnicode = IsTextUnicode(pvFile, dwFileSize, &iUnicodeTestFlags);

if (!*pfIsTextUnicode) {

// For all the file manipulations below, we explicitly use ANSI

// functions because we are processing an ANSI file.

// Put a zero character at the very end of the file.

PSTR pchANSI = (PSTR) pvFile;

pchANSI[dwFileSize / sizeof(CHAR)] = 0;

// Reverse the contents of the file.

_strrev(pchANSI);

// Convert all "\n\r" combinations back to "\r\n" to

// preserve the normal end-of-line sequence.

pchANSI = strchr(pchANSI, '\n'); // Find first '\n'.

while (pchANSI != NULL) {

// We have found an occurrence....

*pchANSI++ = '\r'; // Change '\n' to '\r'.

*pchANSI++ = '\n'; // Change '\r' to '\n'.

pchANSI = strchr(pchANSI, '\n'); // Find the next occurrence.

}

} else {

// For all the file manipulations below, we explicitly use Unicode

// functions because we are processing a Unicode file.

// Put a zero character at the very end of the file.

PWSTR pchUnicode = (PWSTR) pvFile;

pchUnicode[dwFileSize / sizeof(WCHAR)] = 0;

if ((iUnicodeTestFlags & IS_TEXT_UNICODE_SIGNATURE) != 0) {

// If the first character is the Unicode BOM (byte-order-mark),

// 0xFEFF, keep this character at the beginning of the file.

pchUnicode++;

}

// Reverse the contents of the file.

_wcsrev(pchUnicode);

// Convert all "\n\r" combinations back to "\r\n" to

// preserve the normal end-of-line sequence.

pchUnicode = wcschr(pchUnicode, L'\n'); // Find first '\n'.

while (pchUnicode != NULL) {

// We have found an occurrence....

*pchUnicode++ = L'\r'; // Change '\n' to '\r'.

*pchUnicode++ = L'\n'; // Change '\r' to '\n'.

pchUnicode = wcschr(pchUnicode, L'\n'); // Find the next occurrence.

}

}

// Clean up everything before exiting.

UnmapViewOfFile(pvFile);

CloseHandle(hFileMap);

// Remove trailing zero character added earlier.

SetFilePointer(hFile, dwFileSize, NULL, FILE_BEGIN);

SetEndOfFile(hFile);

CloseHandle(hFile);

return(TRUE);

}

///////////////////////////////////////////////////////////////////////////////

BOOL Dlg_OnInitDialog(HWND hwnd, HWND hwndFocus, LPARAM lParam) {

chSETDLGICONS(hwnd, IDI_FILEREV);

// Initialize the dialog box by disabling the Reverse button

EnableWindow(GetDlgItem(hwnd, IDC_REVERSE), FALSE);

return(TRUE);

}

///////////////////////////////////////////////////////////////////////////////

void Dlg_OnCommand(HWND hwnd, int id, HWND hwndCtl, UINT codeNotify) {

TCHAR szPathname[MAX_PATH];

switch (id) {

case IDCANCEL:

EndDialog(hwnd, id);

break;

case IDC_FILENAME:

EnableWindow(GetDlgItem(hwnd, IDC_REVERSE),

Edit_GetTextLength(hwndCtl) > 0);

break;

case IDC_REVERSE:

GetDlgItemText(hwnd, IDC_FILENAME, szPathname, chDIMOF(szPathname));

// Make copy of input file so that we don't destroy it

if (!CopyFile(szPathname, FILENAME, FALSE)) {

chMB("New file could not be created.");

break;

}

BOOL fIsTextUnicode;

if (FileReverse(FILENAME, &fIsTextUnicode)) {

SetDlgItemText(hwnd, IDC_TEXTTYPE,

fIsTextUnicode ? TEXT("Unicode") : TEXT("ANSI"));

// Spawn Notepad to see the fruits of our labors.

STARTUPINFO si = { sizeof(si) };

PROCESS_INFORMATION pi;

TCHAR sz[] = TEXT("Notepad ") FILENAME;

if (CreateProcess(NULL, sz,

NULL, NULL, FALSE, 0, NULL, NULL, &si, &pi)) {

CloseHandle(pi.hThread);

CloseHandle(pi.hProcess);

}

}

break;

case IDC_FILESELECT:

OPENFILENAME ofn = { OPENFILENAME_SIZE_VERSION_400 };

ofn.hwndOwner = hwnd;

ofn.lpstrFile = szPathname;

ofn.lpstrFile[0] = 0;

ofn.nMaxFile = chDIMOF(szPathname);

ofn.lpstrTitle = TEXT("Select file for reversing");

ofn.Flags = OFN_EXPLORER | OFN_FILEMUSTEXIST;

GetOpenFileName(&ofn);

SetDlgItemText(hwnd, IDC_FILENAME, ofn.lpstrFile);

SetFocus(GetDlgItem(hwnd, IDC_REVERSE));

break;

}

}

///////////////////////////////////////////////////////////////////////////////

INT_PTR WINAPI Dlg_Proc(HWND hwnd, UINT uMsg, WPARAM wParam, LPARAM lParam) {

switch (uMsg) {

chHANDLE_DLGMSG(hwnd, WM_INITDIALOG, Dlg_OnInitDialog);

chHANDLE_DLGMSG(hwnd, WM_COMMAND, Dlg_OnCommand);

}

return(FALSE);

}

///////////////////////////////////////////////////////////////////////////////

int WINAPI _tWinMain(HINSTANCE hinstExe, HINSTANCE, PTSTR pszCmdLine, int) {

DialogBox(hinstExe, MAKEINTRESOURCE(IDD_FILEREV), NULL, Dlg_Proc);

return(0);

}

//////////////////////////////// End of File //////////////////////////////////