[reactos] 01/01: [CMDUTILS][FC] Implement text file comparison (#3625)

[Katayama Hirofumi MZ]

https://git.reactos.org/?p=reactos.git;a=commitdiff;h=d2c47132ad3d7c39e88e1…

commit d2c47132ad3d7c39e88e117c0273623726732015
Author:     Katayama Hirofumi MZ <katayama.hirofumi.mz(a)gmail.com>
AuthorDate: Tue May 4 18:05:57 2021 +0900
Commit:     GitHub <noreply(a)github.com>
CommitDate: Tue May 4 18:05:57 2021 +0900

    [CMDUTILS][FC] Implement text file comparison (#3625)
    
    Implement text file comparison by using file mappings (both Unicode and ANSI).
CORE-17500
---
 base/applications/cmdutils/fc/CMakeLists.txt |   6 +-
 base/applications/cmdutils/fc/fc.c           | 381 ++++++++--------
 base/applications/cmdutils/fc/fc.h           |  97 +++++
 base/applications/cmdutils/fc/text.h         | 620 +++++++++++++++++++++++++++
 base/applications/cmdutils/fc/texta.c        |   6 +
 base/applications/cmdutils/fc/textw.c        |   8 +
 6 files changed, 910 insertions(+), 208 deletions(-)

diff --git a/base/applications/cmdutils/fc/CMakeLists.txt
b/base/applications/cmdutils/fc/CMakeLists.txt
index fec64446ae1..4da877ca403 100644
--- a/base/applications/cmdutils/fc/CMakeLists.txt
+++ b/base/applications/cmdutils/fc/CMakeLists.txt
@@ -1,7 +1,7 @@
 include_directories(${REACTOS_SOURCE_DIR}/sdk/lib/conutils)
 
-add_executable(fc fc.c fc.rc)
+add_executable(fc fc.c texta.c textw.c fc.rc)
 set_module_type(fc win32cui UNICODE)
-target_link_libraries(fc conutils ${PSEH_LIB})
-add_importlibs(fc msvcrt user32 kernel32)
+target_link_libraries(fc conutils wine ${PSEH_LIB})
+add_importlibs(fc msvcrt user32 kernel32 ntdll)
 add_cd_file(TARGET fc DESTINATION reactos/system32 FOR all)
diff --git a/base/applications/cmdutils/fc/fc.c b/base/applications/cmdutils/fc/fc.c
index e9ec950bc2d..9350bc1a957 100644
--- a/base/applications/cmdutils/fc/fc.c
+++ b/base/applications/cmdutils/fc/fc.c
@@ -4,87 +4,116 @@
  * PURPOSE:     Comparing files
  * COPYRIGHT:   Copyright 2021 Katayama Hirofumi MZ (katayama.hirofumi.mz(a)gmail.com)
  */
-#include <stdlib.h>
-#include <string.h>
-#include <ctype.h>
-#include <windef.h>
-#include <winbase.h>
-#include <winuser.h>
-#include <winnls.h>
-#include <conutils.h>
-#include "resource.h"
-
-// See also: https://stackoverflow.com/questions/33125766/compare-files-with-a-cmd
-typedef enum FCRET { // return code of FC command
-    FCRET_INVALID = -1,
-    FCRET_IDENTICAL = 0,
-    FCRET_DIFFERENT = 1,
-    FCRET_CANT_FIND = 2
-} FCRET;
-
-#ifdef _WIN64
-    #define MAX_VIEW_SIZE (256 * 1024 * 1024) // 256 MB
+#include "fc.h"
+
+#ifdef __REACTOS__
+    #include <conutils.h>
 #else
-    #define MAX_VIEW_SIZE (64 * 1024 * 1024) // 64 MB
+    #include <stdio.h>
+    #define ConInitStdStreams() /* empty */
+    #define StdOut stdout
+    #define StdErr stderr
+    void ConPuts(FILE *fp, LPCWSTR psz)
+    {
+        fputws(psz, fp);
+    }
+    void ConPrintf(FILE *fp, LPCWSTR psz, ...)
+    {
+        va_list va;
+        va_start(va, psz);
+        vfwprintf(fp, psz, va);
+        va_end(va);
+    }
+    void ConResPuts(FILE *fp, UINT nID)
+    {
+        WCHAR sz[MAX_PATH];
+        LoadStringW(NULL, nID, sz, _countof(sz));
+        fputws(sz, fp);
+    }
+    void ConResPrintf(FILE *fp, UINT nID, ...)
+    {
+        va_list va;
+        WCHAR sz[MAX_PATH];
+        va_start(va, nID);
+        LoadStringW(NULL, nID, sz, _countof(sz));
+        vfwprintf(fp, sz, va);
+        va_end(va);
+    }
 #endif
 
-#define FLAG_A (1 << 0)
-#define FLAG_B (1 << 1)
-#define FLAG_C (1 << 2)
-#define FLAG_L (1 << 3)
-#define FLAG_LBn (1 << 4)
-#define FLAG_N (1 << 5)
-#define FLAG_OFFLINE (1 << 6)
-#define FLAG_T (1 << 7)
-#define FLAG_U (1 << 8)
-#define FLAG_W (1 << 9)
-#define FLAG_nnnn (1 << 10)
-#define FLAG_HELP (1 << 11)
-
-typedef struct FILECOMPARE
-{
-    DWORD dwFlags; // FLAG_...
-    INT n, nnnn;
-    LPCWSTR file1, file2;
-} FILECOMPARE;
-
-static FCRET NoDifference(VOID)
+FCRET NoDifference(VOID)
 {
     ConResPuts(StdOut, IDS_NO_DIFFERENCE);
     return FCRET_IDENTICAL;
 }
 
-static FCRET Different(LPCWSTR file1, LPCWSTR file2)
+FCRET Different(LPCWSTR file0, LPCWSTR file1)
 {
-    ConResPrintf(StdOut, IDS_DIFFERENT, file1, file2);
+    ConResPrintf(StdOut, IDS_DIFFERENT, file0, file1);
     return FCRET_DIFFERENT;
 }
 
-static FCRET LongerThan(LPCWSTR file1, LPCWSTR file2)
+FCRET LongerThan(LPCWSTR file0, LPCWSTR file1)
 {
-    ConResPrintf(StdOut, IDS_LONGER_THAN, file1, file2);
+    ConResPrintf(StdOut, IDS_LONGER_THAN, file0, file1);
     return FCRET_DIFFERENT;
 }
 
-static FCRET OutOfMemory(VOID)
+FCRET OutOfMemory(VOID)
 {
     ConResPuts(StdErr, IDS_OUT_OF_MEMORY);
     return FCRET_INVALID;
 }
 
-static FCRET CannotRead(LPCWSTR file)
+FCRET CannotRead(LPCWSTR file)
 {
     ConResPrintf(StdErr, IDS_CANNOT_READ, file);
     return FCRET_INVALID;
 }
 
-static FCRET InvalidSwitch(VOID)
+FCRET InvalidSwitch(VOID)
 {
     ConResPuts(StdErr, IDS_INVALID_SWITCH);
     return FCRET_INVALID;
 }
 
-static HANDLE DoOpenFileForInput(LPCWSTR file)
+FCRET ResyncFailed(VOID)
+{
+    ConResPuts(StdOut, IDS_RESYNC_FAILED);
+    return FCRET_DIFFERENT;
+}
+
+VOID PrintCaption(LPCWSTR file)
+{
+    ConPrintf(StdOut, L"***** %ls\n", file);
+}
+
+VOID PrintEndOfDiff(VOID)
+{
+    ConPuts(StdOut, L"*****\n\n");
+}
+
+VOID PrintDots(VOID)
+{
+    ConPuts(StdOut, L"...\n");
+}
+
+VOID PrintLineW(const FILECOMPARE *pFC, DWORD lineno, LPCWSTR psz)
+{
+    if (pFC->dwFlags & FLAG_N)
+        ConPrintf(StdOut, L"%5d:  %ls\n", lineno, psz);
+    else
+        ConPrintf(StdOut, L"%ls\n", psz);
+}
+VOID PrintLineA(const FILECOMPARE *pFC, DWORD lineno, LPCSTR psz)
+{
+    if (pFC->dwFlags & FLAG_N)
+        ConPrintf(StdOut, L"%5d:  %hs\n", lineno, psz);
+    else
+        ConPrintf(StdOut, L"%hs\n", psz);
+}
+
+HANDLE DoOpenFileForInput(LPCWSTR file)
 {
     HANDLE hFile = CreateFileW(file, GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING,
0, NULL);
     if (hFile == INVALID_HANDLE_VALUE)
@@ -97,54 +126,54 @@ static HANDLE DoOpenFileForInput(LPCWSTR file)
 static FCRET BinaryFileCompare(FILECOMPARE *pFC)
 {
     FCRET ret;
-    HANDLE hFile1, hFile2, hMapping1 = NULL, hMapping2 = NULL;
-    LPBYTE pb1 = NULL, pb2 = NULL;
-    LARGE_INTEGER ib, cb1, cb2, cbCommon;
+    HANDLE hFile0, hFile1, hMapping0 = NULL, hMapping1 = NULL;
+    LPBYTE pb0 = NULL, pb1 = NULL;
+    LARGE_INTEGER ib, cb0, cb1, cbCommon;
     DWORD cbView, ibView;
     BOOL fDifferent = FALSE;
 
-    hFile1 = DoOpenFileForInput(pFC->file1);
-    if (hFile1 == INVALID_HANDLE_VALUE)
+    hFile0 = DoOpenFileForInput(pFC->file[0]);
+    if (hFile0 == INVALID_HANDLE_VALUE)
         return FCRET_CANT_FIND;
-    hFile2 = DoOpenFileForInput(pFC->file2);
-    if (hFile2 == INVALID_HANDLE_VALUE)
+    hFile1 = DoOpenFileForInput(pFC->file[1]);
+    if (hFile1 == INVALID_HANDLE_VALUE)
     {
-        CloseHandle(hFile1);
+        CloseHandle(hFile0);
         return FCRET_CANT_FIND;
     }
 
     do
     {
-        if (_wcsicmp(pFC->file1, pFC->file2) == 0)
+        if (_wcsicmp(pFC->file[0], pFC->file[1]) == 0)
         {
             ret = NoDifference();
             break;
         }
-        if (!GetFileSizeEx(hFile1, &cb1))
+        if (!GetFileSizeEx(hFile0, &cb0))
         {
-            ret = CannotRead(pFC->file1);
+            ret = CannotRead(pFC->file[0]);
             break;
         }
-        if (!GetFileSizeEx(hFile2, &cb2))
+        if (!GetFileSizeEx(hFile1, &cb1))
         {
-            ret = CannotRead(pFC->file2);
+            ret = CannotRead(pFC->file[1]);
             break;
         }
-        cbCommon.QuadPart = min(cb1.QuadPart, cb2.QuadPart);
+        cbCommon.QuadPart = min(cb0.QuadPart, cb1.QuadPart);
         if (cbCommon.QuadPart > 0)
         {
-            hMapping1 = CreateFileMappingW(hFile1, NULL, PAGE_READONLY,
-                                           cb1.HighPart, cb1.LowPart, NULL);
-            if (hMapping1 == NULL)
+            hMapping0 = CreateFileMappingW(hFile0, NULL, PAGE_READONLY,
+                                           cb0.HighPart, cb0.LowPart, NULL);
+            if (hMapping0 == NULL)
             {
-                ret = CannotRead(pFC->file1);
+                ret = CannotRead(pFC->file[0]);
                 break;
             }
-            hMapping2 = CreateFileMappingW(hFile2, NULL, PAGE_READONLY,
-                                           cb2.HighPart, cb2.LowPart, NULL);
-            if (hMapping2 == NULL)
+            hMapping1 = CreateFileMappingW(hFile1, NULL, PAGE_READONLY,
+                                           cb1.HighPart, cb1.LowPart, NULL);
+            if (hMapping1 == NULL)
             {
-                ret = CannotRead(pFC->file2);
+                ret = CannotRead(pFC->file[1]);
                 break;
             }
 
@@ -152,197 +181,121 @@ static FCRET BinaryFileCompare(FILECOMPARE *pFC)
             for (ib.QuadPart = 0; ib.QuadPart < cbCommon.QuadPart; )
             {
                 cbView = (DWORD)min(cbCommon.QuadPart - ib.QuadPart, MAX_VIEW_SIZE);
+                pb0 = MapViewOfFile(hMapping0, FILE_MAP_READ, ib.HighPart, ib.LowPart,
cbView);
                 pb1 = MapViewOfFile(hMapping1, FILE_MAP_READ, ib.HighPart, ib.LowPart,
cbView);
-                pb2 = MapViewOfFile(hMapping2, FILE_MAP_READ, ib.HighPart, ib.LowPart,
cbView);
-                if (!pb1 || !pb2)
+                if (!pb0 || !pb1)
                 {
                     ret = OutOfMemory();
                     break;
                 }
                 for (ibView = 0; ibView < cbView; ++ib.QuadPart, ++ibView)
                 {
-                    if (pb1[ibView] == pb2[ibView])
+                    if (pb0[ibView] == pb1[ibView])
                         continue;
 
                     fDifferent = TRUE;
                     if (cbCommon.QuadPart > MAXDWORD)
                     {
                         ConPrintf(StdOut, L"%016I64X: %02X %02X\n",
ib.QuadPart,
-                                  pb1[ibView], pb2[ibView]);
+                                  pb0[ibView], pb1[ibView]);
                     }
                     else
                     {
                         ConPrintf(StdOut, L"%08lX: %02X %02X\n", ib.LowPart,
-                                  pb1[ibView], pb2[ibView]);
+                                  pb0[ibView], pb1[ibView]);
                     }
                 }
+                UnmapViewOfFile(pb0);
                 UnmapViewOfFile(pb1);
-                UnmapViewOfFile(pb2);
-                pb1 = pb2 = NULL;
+                pb0 = pb1 = NULL;
             }
             if (ret != FCRET_IDENTICAL)
                 break;
         }
 
-        if (cb1.QuadPart < cb2.QuadPart)
-            ret = LongerThan(pFC->file2, pFC->file1);
-        else if (cb1.QuadPart > cb2.QuadPart)
-            ret = LongerThan(pFC->file1, pFC->file2);
+        if (cb0.QuadPart < cb1.QuadPart)
+            ret = LongerThan(pFC->file[1], pFC->file[0]);
+        else if (cb0.QuadPart > cb1.QuadPart)
+            ret = LongerThan(pFC->file[0], pFC->file[1]);
         else if (fDifferent)
-            ret = Different(pFC->file1, pFC->file2);
+            ret = Different(pFC->file[0], pFC->file[1]);
         else
             ret = NoDifference();
     } while (0);
 
+    UnmapViewOfFile(pb0);
     UnmapViewOfFile(pb1);
-    UnmapViewOfFile(pb2);
+    CloseHandle(hMapping0);
     CloseHandle(hMapping1);
-    CloseHandle(hMapping2);
+    CloseHandle(hFile0);
     CloseHandle(hFile1);
-    CloseHandle(hFile2);
-    return ret;
-}
-
-static FCRET
-UnicodeTextCompare(FILECOMPARE *pFC, HANDLE hMapping1, const LARGE_INTEGER *pcb1,
-                                     HANDLE hMapping2, const LARGE_INTEGER *pcb2)
-{
-    FCRET ret;
-    BOOL fIgnoreCase = !!(pFC->dwFlags & FLAG_C);
-    DWORD dwCmpFlags = (fIgnoreCase ? NORM_IGNORECASE : 0);
-    LPCWSTR psz1, psz2;
-    LARGE_INTEGER cch1 = { .QuadPart = pcb1->QuadPart / sizeof(WCHAR) };
-    LARGE_INTEGER cch2 = { .QuadPart = pcb1->QuadPart / sizeof(WCHAR) };
-
-    do
-    {
-        psz1 = MapViewOfFile(hMapping1, FILE_MAP_READ, 0, 0, pcb1->LowPart);
-        psz2 = MapViewOfFile(hMapping2, FILE_MAP_READ, 0, 0, pcb2->LowPart);
-        if (!psz1 || !psz2)
-        {
-            ret = OutOfMemory();
-            break;
-        }
-        if (cch1.QuadPart < MAXLONG && cch2.QuadPart < MAXLONG)
-        {
-            if (CompareStringW(0, dwCmpFlags, psz1, cch1.LowPart,
-                                              psz2, cch2.LowPart) == CSTR_EQUAL)
-            {
-                ret = NoDifference();
-                break;
-            }
-        }
-        // TODO: compare each lines
-        // TODO: large file support
-        ret = Different(pFC->file1, pFC->file2);
-    } while (0);
-
-    UnmapViewOfFile(psz1);
-    UnmapViewOfFile(psz2);
-    return ret;
-}
-
-static FCRET
-AnsiTextCompare(FILECOMPARE *pFC, HANDLE hMapping1, const LARGE_INTEGER *pcb1,
-                                  HANDLE hMapping2, const LARGE_INTEGER *pcb2)
-{
-    FCRET ret;
-    BOOL fIgnoreCase = !!(pFC->dwFlags & FLAG_C);
-    DWORD dwCmpFlags = (fIgnoreCase ? NORM_IGNORECASE : 0);
-    LPSTR psz1, psz2;
-
-    do
-    {
-        psz1 = MapViewOfFile(hMapping1, FILE_MAP_READ, 0, 0, pcb1->LowPart);
-        psz2 = MapViewOfFile(hMapping2, FILE_MAP_READ, 0, 0, pcb2->LowPart);
-        if (!psz1 || !psz2)
-        {
-            ret = OutOfMemory();
-            break;
-        }
-        if (pcb1->QuadPart < MAXLONG && pcb2->QuadPart < MAXLONG)
-        {
-            if (CompareStringA(0, dwCmpFlags, psz1, pcb1->LowPart,
-                                              psz2, pcb2->LowPart) == CSTR_EQUAL)
-            {
-                ret = NoDifference();
-                break;
-            }
-        }
-        // TODO: compare each lines
-        // TODO: large file support
-        ret = Different(pFC->file1, pFC->file2);
-    } while (0);
-
-    UnmapViewOfFile(psz1);
-    UnmapViewOfFile(psz2);
     return ret;
 }
 
 static FCRET TextFileCompare(FILECOMPARE *pFC)
 {
     FCRET ret;
-    HANDLE hFile1, hFile2, hMapping1 = NULL, hMapping2 = NULL;
-    LARGE_INTEGER cb1, cb2;
+    HANDLE hFile0, hFile1, hMapping0 = NULL, hMapping1 = NULL;
+    LARGE_INTEGER cb0, cb1;
     BOOL fUnicode = !!(pFC->dwFlags & FLAG_U);
 
-    hFile1 = DoOpenFileForInput(pFC->file1);
-    if (hFile1 == INVALID_HANDLE_VALUE)
+    hFile0 = DoOpenFileForInput(pFC->file[0]);
+    if (hFile0 == INVALID_HANDLE_VALUE)
         return FCRET_CANT_FIND;
-    hFile2 = DoOpenFileForInput(pFC->file2);
-    if (hFile2 == INVALID_HANDLE_VALUE)
+    hFile1 = DoOpenFileForInput(pFC->file[1]);
+    if (hFile1 == INVALID_HANDLE_VALUE)
     {
-        CloseHandle(hFile1);
+        CloseHandle(hFile0);
         return FCRET_CANT_FIND;
     }
 
     do
     {
-        if (_wcsicmp(pFC->file1, pFC->file2) == 0)
+        if (_wcsicmp(pFC->file[0], pFC->file[1]) == 0)
         {
             ret = NoDifference();
             break;
         }
-        if (!GetFileSizeEx(hFile1, &cb1))
+        if (!GetFileSizeEx(hFile0, &cb0))
         {
-            ret = CannotRead(pFC->file1);
+            ret = CannotRead(pFC->file[0]);
             break;
         }
-        if (!GetFileSizeEx(hFile2, &cb2))
+        if (!GetFileSizeEx(hFile1, &cb1))
         {
-            ret = CannotRead(pFC->file2);
+            ret = CannotRead(pFC->file[1]);
             break;
         }
-        if (cb1.QuadPart == 0 && cb2.QuadPart == 0)
+        if (cb0.QuadPart == 0 && cb1.QuadPart == 0)
         {
             ret = NoDifference();
             break;
         }
-        hMapping1 = CreateFileMappingW(hFile1, NULL, PAGE_READONLY,
-                                       cb1.HighPart, cb1.LowPart, NULL);
-        if (hMapping1 == NULL)
+        hMapping0 = CreateFileMappingW(hFile0, NULL, PAGE_READONLY,
+                                       cb0.HighPart, cb0.LowPart, NULL);
+        if (hMapping0 == NULL)
         {
-            ret = CannotRead(pFC->file1);
+            ret = CannotRead(pFC->file[0]);
             break;
         }
-        hMapping2 = CreateFileMappingW(hFile2, NULL, PAGE_READONLY,
-                                       cb2.HighPart, cb2.LowPart, NULL);
-        if (hMapping2 == NULL)
+        hMapping1 = CreateFileMappingW(hFile1, NULL, PAGE_READONLY,
+                                       cb1.HighPart, cb1.LowPart, NULL);
+        if (hMapping1 == NULL)
         {
-            ret = CannotRead(pFC->file2);
+            ret = CannotRead(pFC->file[1]);
             break;
         }
 
         if (fUnicode)
-            ret = UnicodeTextCompare(pFC, hMapping1, &cb1, hMapping2, &cb2);
+            ret = TextCompareW(pFC, &hMapping0, &cb0, &hMapping1, &cb1);
         else
-            ret = AnsiTextCompare(pFC, hMapping1, &cb1, hMapping2, &cb2);
+            ret = TextCompareA(pFC, &hMapping0, &cb0, &hMapping1, &cb1);
     } while (0);
 
+    CloseHandle(hMapping0);
     CloseHandle(hMapping1);
-    CloseHandle(hMapping2);
+    CloseHandle(hFile0);
     CloseHandle(hFile1);
-    CloseHandle(hFile2);
     return ret;
 }
 
@@ -352,17 +305,17 @@ static BOOL IsBinaryExt(LPCWSTR filename)
     // See also:
https://docs.microsoft.com/en-us/windows-server/administration/windows-comm…
     static const LPCWSTR s_exts[] = { L"EXE", L"COM",
L"SYS", L"OBJ", L"LIB", L"BIN" };
     size_t iext;
-    LPCWSTR pch, ext, pch1 = wcsrchr(filename, L'\\'), pch2 = wcsrchr(filename,
L'/');
-    if (!pch1 && !pch2)
+    LPCWSTR pch, ext, pch0 = wcsrchr(filename, L'\\'), pch1 = wcsrchr(filename,
L'/');
+    if (!pch0 && !pch1)
         pch = filename;
-    else if (!pch1 && pch2)
-        pch = pch2;
-    else if (pch1 && !pch2)
+    else if (!pch0 && pch1)
         pch = pch1;
-    else if (pch1 < pch2)
-        pch = pch2;
-    else
+    else if (pch0 && !pch1)
+        pch = pch0;
+    else if (pch0 < pch1)
         pch = pch1;
+    else
+        pch = pch0;
 
     ext = wcsrchr(pch, L'.');
     if (ext)
@@ -382,10 +335,10 @@ static BOOL IsBinaryExt(LPCWSTR filename)
 
 static FCRET FileCompare(FILECOMPARE *pFC)
 {
-    ConResPrintf(StdOut, IDS_COMPARING, pFC->file1, pFC->file2);
+    ConResPrintf(StdOut, IDS_COMPARING, pFC->file[0], pFC->file[1]);
 
     if (!(pFC->dwFlags & FLAG_L) &&
-        ((pFC->dwFlags & FLAG_B) || IsBinaryExt(pFC->file1) ||
IsBinaryExt(pFC->file2)))
+        ((pFC->dwFlags & FLAG_B) || IsBinaryExt(pFC->file[0]) ||
IsBinaryExt(pFC->file[1])))
     {
         return BinaryFileCompare(pFC);
     }
@@ -394,25 +347,29 @@ static FCRET FileCompare(FILECOMPARE *pFC)
 
 static FCRET WildcardFileCompare(FILECOMPARE *pFC)
 {
+    FCRET ret;
+
     if (pFC->dwFlags & FLAG_HELP)
     {
         ConResPuts(StdOut, IDS_USAGE);
         return FCRET_INVALID;
     }
 
-    if (!pFC->file1 || !pFC->file2)
+    if (!pFC->file[0] || !pFC->file[1])
     {
         ConResPuts(StdErr, IDS_NEEDS_FILES);
         return FCRET_INVALID;
     }
 
-    if (HasWildcard(pFC->file1) || HasWildcard(pFC->file2))
+    if (HasWildcard(pFC->file[0]) || HasWildcard(pFC->file[1]))
     {
         // TODO: wildcard
         ConResPuts(StdErr, IDS_CANT_USE_WILDCARD);
     }
 
-    return FileCompare(pFC);
+    ret = FileCompare(pFC);
+    ConPuts(StdOut, L"\n");
+    return ret;
 }
 
 int wmain(int argc, WCHAR **argv)
@@ -428,10 +385,10 @@ int wmain(int argc, WCHAR **argv)
     {
         if (argv[i][0] != L'/')
         {
-            if (!fc.file1)
-                fc.file1 = argv[i];
-            else if (!fc.file2)
-                fc.file2 = argv[i];
+            if (!fc.file[0])
+                fc.file[0] = argv[i];
+            else if (!fc.file[1])
+                fc.file[1] = argv[i];
             else
                 return InvalidSwitch();
             continue;
@@ -479,6 +436,9 @@ int wmain(int argc, WCHAR **argv)
             case L'T':
                 fc.dwFlags |= FLAG_T;
                 break;
+            case L'U':
+                fc.dwFlags |= FLAG_U;
+                break;
             case L'W':
                 fc.dwFlags |= FLAG_W;
                 break;
@@ -498,3 +458,14 @@ int wmain(int argc, WCHAR **argv)
     }
     return WildcardFileCompare(&fc);
 }
+
+#ifndef __REACTOS__
+int main(int argc, char **argv)
+{
+    INT my_argc;
+    LPWSTR *my_argv = CommandLineToArgvW(GetCommandLineW(), &my_argc);
+    INT ret = wmain(my_argc, my_argv);
+    LocalFree(my_argv);
+    return ret;
+}
+#endif
diff --git a/base/applications/cmdutils/fc/fc.h b/base/applications/cmdutils/fc/fc.h
new file mode 100644
index 00000000000..3d8772e78c7
--- /dev/null
+++ b/base/applications/cmdutils/fc/fc.h
@@ -0,0 +1,97 @@
+/*
+ * PROJECT:     ReactOS FC Command
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     Comparing files
+ * COPYRIGHT:   Copyright 2021 Katayama Hirofumi MZ (katayama.hirofumi.mz(a)gmail.com)
+ */
+#pragma once
+#include <stdlib.h>
+#include <string.h>
+#include <ctype.h>
+#ifdef __REACTOS__
+    #include <windef.h>
+    #include <winbase.h>
+    #include <winuser.h>
+    #include <winnls.h>
+#else
+    #include <windows.h>
+#endif
+#include <wine/list.h>
+#include "resource.h"
+
+// See also: https://stackoverflow.com/questions/33125766/compare-files-with-a-cmd
+typedef enum FCRET // return code of FC command
+{
+    FCRET_INVALID = -1,
+    FCRET_IDENTICAL = 0,
+    FCRET_DIFFERENT = 1,
+    FCRET_CANT_FIND = 2,
+    FCRET_NO_MORE_DATA = 3 // (extension)
+} FCRET;
+
+typedef struct NODE_W
+{
+    struct list entry;
+    LPWSTR pszLine;
+    LPWSTR pszComp; // compressed
+    DWORD lineno;
+    DWORD hash;
+} NODE_W;
+typedef struct NODE_A
+{
+    struct list entry;
+    LPSTR pszLine;
+    LPSTR pszComp; // compressed
+    DWORD lineno;
+    DWORD hash;
+} NODE_A;
+
+#define FLAG_A (1 << 0) // abbreviation
+#define FLAG_B (1 << 1) // binary
+#define FLAG_C (1 << 2) // ignore cases
+#define FLAG_L (1 << 3) // ASCII mode
+#define FLAG_LBn (1 << 4) // line buffers
+#define FLAG_N (1 << 5) // show line numbers
+#define FLAG_OFFLINE (1 << 6) // ???
+#define FLAG_T (1 << 7) // prevent fc from converting tabs to spaces
+#define FLAG_U (1 << 8) // Unicode
+#define FLAG_W (1 << 9) // compress white space
+#define FLAG_nnnn (1 << 10) // ???
+#define FLAG_HELP (1 << 11) // show usage
+
+typedef struct FILECOMPARE
+{
+    DWORD dwFlags; // FLAG_...
+    INT n; // # of line buffers
+    INT nnnn; // retry count before resynch
+    LPCWSTR file[2];
+    struct list list[2];
+} FILECOMPARE;
+
+// text.h
+FCRET TextCompareW(FILECOMPARE *pFC,
+                   HANDLE *phMapping0, const LARGE_INTEGER *pcb0,
+                   HANDLE *phMapping1, const LARGE_INTEGER *pcb1);
+FCRET TextCompareA(FILECOMPARE *pFC,
+                   HANDLE *phMapping0, const LARGE_INTEGER *pcb0,
+                   HANDLE *phMapping1, const LARGE_INTEGER *pcb1);
+// fc.c
+VOID PrintLineW(const FILECOMPARE *pFC, DWORD lineno, LPCWSTR psz);
+VOID PrintLineA(const FILECOMPARE *pFC, DWORD lineno, LPCSTR psz);
+VOID PrintCaption(LPCWSTR file);
+VOID PrintEndOfDiff(VOID);
+VOID PrintDots(VOID);
+FCRET NoDifference(VOID);
+FCRET Different(LPCWSTR file0, LPCWSTR file1);
+FCRET LongerThan(LPCWSTR file0, LPCWSTR file1);
+FCRET OutOfMemory(VOID);
+FCRET CannotRead(LPCWSTR file);
+FCRET InvalidSwitch(VOID);
+FCRET ResyncFailed(VOID);
+HANDLE DoOpenFileForInput(LPCWSTR file);
+
+#ifdef _WIN64
+    #define MAX_VIEW_SIZE (256 * 1024 * 1024) // 256 MB
+#else
+    #define MAX_VIEW_SIZE (64 * 1024 * 1024) // 64 MB
+#endif
diff --git a/base/applications/cmdutils/fc/text.h b/base/applications/cmdutils/fc/text.h
new file mode 100644
index 00000000000..d0f2363f6f9
--- /dev/null
+++ b/base/applications/cmdutils/fc/text.h
@@ -0,0 +1,620 @@
+/*
+ * PROJECT:     ReactOS FC Command
+ * LICENSE:     GPL-2.0-or-later (https://spdx.org/licenses/GPL-2.0-or-later)
+ * PURPOSE:     Comparing text files
+ * COPYRIGHT:   Copyright 2021 Katayama Hirofumi MZ (katayama.hirofumi.mz(a)gmail.com)
+ */
+#include "fc.h"
+#include <stdio.h>
+
+#ifdef __REACTOS__
+    #include <wine/debug.h>
+    WINE_DEFAULT_DEBUG_CHANNEL(fc);
+#else
+    #define ERR /*empty*/
+    #define WARN /*empty*/
+    #define TRACE /*empty*/
+#endif
+
+#define IS_SPACE(ch) ((ch) == TEXT(' ') || (ch) == TEXT('\t'))
+
+#ifdef UNICODE
+    #define NODE NODE_W
+    #define PrintLine PrintLineW
+    #define TextCompare TextCompareW
+#else
+    #define NODE NODE_A
+    #define PrintLine PrintLineA
+    #define TextCompare TextCompareA
+#endif
+
+static LPTSTR AllocLine(LPCTSTR pch, DWORD cch)
+{
+    LPTSTR pszNew = malloc((cch + 1) * sizeof(TCHAR));
+    if (!pszNew)
+        return NULL;
+    memcpy(pszNew, pch, cch * sizeof(TCHAR));
+    pszNew[cch] = 0;
+    return pszNew;
+}
+
+static NODE *AllocNode(LPTSTR psz, DWORD lineno)
+{
+    NODE *node;
+    if (!psz)
+        return NULL;
+    node = calloc(1, sizeof(NODE));
+    if (!node)
+    {
+        free(psz);
+        return NULL;
+    }
+    node->pszLine = psz;
+    node->lineno = lineno;
+    return node;
+}
+
+static __inline VOID DeleteNode(NODE *node)
+{
+    if (node)
+    {
+        free(node->pszLine);
+        free(node->pszComp);
+        free(node);
+    }
+}
+
+static VOID DeleteList(struct list *list)
+{
+    struct list *ptr;
+    NODE *node;
+    while ((ptr = list_head(list)) != NULL)
+    {
+        list_remove(ptr);
+        node = LIST_ENTRY(ptr, NODE, entry);
+        DeleteNode(node);
+    }
+}
+
+static __inline LPCTSTR SkipSpace(LPCTSTR pch)
+{
+    while (IS_SPACE(*pch))
+        ++pch;
+    return pch;
+}
+
+static __inline LPCTSTR FindLastNonSpace(LPCTSTR pch)
+{
+    LPCTSTR pchLast = NULL;
+    while (*pch)
+    {
+        if (!IS_SPACE(*pch))
+            pchLast = pch;
+        ++pch;
+    }
+    return pchLast;
+}
+
+static VOID DeleteDuplicateSpaces(LPTSTR psz)
+{
+    LPTSTR pch0, pch1;
+    for (pch0 = pch1 = psz; *pch0; ++pch0)
+    {
+        *pch1++ = *pch0;
+        if (IS_SPACE(*pch0))
+        {
+            do
+            {
+                ++pch0;
+            } while (IS_SPACE(*pch0));
+            --pch0;
+        }
+    }
+    *pch1 = 0;
+}
+
+static LPTSTR CompressSpace(LPCTSTR line)
+{
+    LPTSTR pszNew;
+    LPCTSTR pchLast;
+
+    line = SkipSpace(line);
+    pchLast = FindLastNonSpace(line);
+    if (pchLast == NULL)
+        return AllocLine(NULL, 0);
+
+    pszNew = AllocLine(line, (DWORD)(pchLast - line) + 1);
+    if (!pszNew)
+        return NULL;
+
+    DeleteDuplicateSpaces(pszNew);
+    return pszNew;
+}
+
+#define TAB_WIDTH 8
+
+static INT ExpandTabLength(LPCTSTR line)
+{
+    LPCTSTR pch;
+    INT cch = 0;
+    for (pch = line; *pch; ++pch)
+    {
+        if (*pch == TEXT('\t'))
+            cch += TAB_WIDTH - (cch % TAB_WIDTH);
+        else
+            ++cch;
+    }
+    return cch;
+}
+
+static LPTSTR ExpandTab(LPCTSTR line)
+{
+    INT spaces, cch = ExpandTabLength(line), ich;
+    LPTSTR pszNew = malloc((cch + 1) * sizeof(TCHAR));
+    LPCTSTR pch;
+    if (!pszNew)
+        return NULL;
+    ich = 0;
+    for (pch = line; *pch; ++pch)
+    {
+        if (*pch == TEXT('\t'))
+        {
+            spaces = TAB_WIDTH - (ich % TAB_WIDTH);
+            while (spaces-- > 0)
+            {
+                pszNew[ich++] = TEXT(' ');
+            }
+        }
+        else
+        {
+            pszNew[ich++] = *pch;
+        }
+    }
+    pszNew[ich] = 0;
+    return pszNew;
+}
+
+#define HASH_EOF 0xFFFFFFFF
+#define HASH_MASK 0x7FFFFFFF
+
+static DWORD GetHash(LPCTSTR psz, BOOL bIgnoreCase)
+{
+    DWORD ret = 0xDEADFACE;
+    while (*psz)
+    {
+        ret += (bIgnoreCase ? towupper(*psz) : *psz);
+        ret <<= 2;
+        ++psz;
+    }
+    return (ret & HASH_MASK);
+}
+
+static NODE *AllocEOFNode(DWORD lineno)
+{
+    NODE *node = AllocNode(AllocLine(NULL, 0), 0);
+    if (node == NULL)
+        return NULL;
+    node->pszComp = AllocLine(NULL, 0);
+    if (node->pszComp == NULL)
+    {
+        DeleteNode(node);
+        return NULL;
+    }
+    node->lineno = lineno;
+    node->hash = HASH_EOF;
+    return node;
+}
+
+static __inline BOOL IsEOFNode(NODE *node)
+{
+    return !node || node->hash == HASH_EOF;
+}
+
+static BOOL ConvertNode(const FILECOMPARE *pFC, NODE *node)
+{
+    if (!(pFC->dwFlags & FLAG_T))
+    {
+        LPTSTR tmp = ExpandTab(node->pszLine);
+        if (!tmp)
+            return FALSE;
+        free(node->pszLine);
+        node->pszLine = tmp;
+        if (!(pFC->dwFlags & FLAG_W))
+            node->hash = GetHash(node->pszLine, !!(pFC->dwFlags & FLAG_C));
+    }
+    if (pFC->dwFlags & FLAG_W)
+    {
+        node->pszComp = CompressSpace(node->pszLine);
+        if (!node->pszComp)
+            return FALSE;
+        node->hash = GetHash(node->pszComp, !!(pFC->dwFlags & FLAG_C));
+    }
+    return TRUE;
+}
+
+static FCRET CompareNode(const FILECOMPARE *pFC, const NODE *node0, const NODE *node1)
+{
+    DWORD dwCmpFlags;
+    LPTSTR psz0, psz1;
+    INT ret;
+    if (node0->hash != node1->hash)
+        return FCRET_DIFFERENT;
+
+    psz0 = (pFC->dwFlags & FLAG_W) ? node0->pszComp : node0->pszLine;
+    psz1 = (pFC->dwFlags & FLAG_W) ? node1->pszComp : node1->pszLine;
+    dwCmpFlags = ((pFC->dwFlags & FLAG_C) ? NORM_IGNORECASE : 0);
+    ret = CompareString(LOCALE_USER_DEFAULT, dwCmpFlags, psz0, -1, psz1, -1);
+    return (ret == CSTR_EQUAL) ? FCRET_IDENTICAL : FCRET_DIFFERENT;
+}
+
+static BOOL FindNextLine(LPCTSTR pch, DWORD ich, DWORD cch, LPDWORD pich)
+{
+    while (ich < cch)
+    {
+        if (pch[ich] == TEXT('\n') || pch[ich] == TEXT('\0'))
+        {
+            *pich = ich;
+            return TRUE;
+        }
+        ++ich;
+    }
+    *pich = cch;
+    return FALSE;
+}
+
+static FCRET
+ParseLines(const FILECOMPARE *pFC, HANDLE *phMapping,
+           LARGE_INTEGER *pib, const LARGE_INTEGER *pcb, struct list *list)
+{
+    DWORD lineno = 1, ich, cch, ichNext, cbView, cchNode;
+    LPTSTR psz, pszLine;
+    BOOL fLast, bCR;
+    NODE *node;
+
+    if (*phMapping == NULL)
+        return FCRET_NO_MORE_DATA;
+
+    if (pib->QuadPart >= pcb->QuadPart)
+    {
+        CloseHandle(*phMapping);
+        *phMapping = NULL;
+        return FCRET_NO_MORE_DATA;
+    }
+
+    cbView = (DWORD)min(pcb->QuadPart - pib->QuadPart, MAX_VIEW_SIZE);
+    psz = MapViewOfFile(*phMapping, FILE_MAP_READ, pib->HighPart, pib->LowPart,
cbView);
+    if (!psz)
+    {
+        return OutOfMemory();
+    }
+
+    ich = 0;
+    cch = cbView / sizeof(TCHAR);
+    fLast = (pib->QuadPart + cbView >= pcb->QuadPart);
+    while (ich < cch &&
+           (FindNextLine(psz, ich, cch, &ichNext) ||
+            (ichNext == cch && (fLast || ich == 0))))
+    {
+        bCR = (ichNext > 0) && (psz[ichNext - 1] == TEXT('\r'));
+        cchNode = ichNext - ich - bCR;
+        TRACE("ich:%ld, cch:%ld, ichNext:%ld, cchNode:%ld\n", ich, cch,
ichNext, cchNode);
+        pszLine = AllocLine(&psz[ich], cchNode);
+        node = AllocNode(pszLine, lineno++);
+        if (!node || !ConvertNode(pFC, node))
+        {
+            DeleteNode(node);
+            UnmapViewOfFile(psz);
+            return OutOfMemory();
+        }
+        list_add_tail(list, &node->entry);
+        ich = ichNext + 1;
+    }
+
+    UnmapViewOfFile(psz);
+
+    pib->QuadPart += ichNext * sizeof(WCHAR);
+
+    if (pib->QuadPart < pcb->QuadPart)
+        return FCRET_IDENTICAL;
+
+    // append EOF node
+    node = AllocEOFNode(lineno);
+    if (!node)
+        return OutOfMemory();
+    list_add_tail(list, &node->entry);
+
+    return FCRET_NO_MORE_DATA;
+}
+
+static VOID
+ShowDiff(FILECOMPARE *pFC, INT i, struct list *begin, struct list *end)
+{
+    NODE* node;
+    struct list *list = &pFC->list[i];
+    struct list *first = NULL, *last = NULL;
+    PrintCaption(pFC->file[i]);
+    if (begin && end && list_prev(list, begin))
+        begin = list_prev(list, begin);
+    while (begin != end)
+    {
+        node = LIST_ENTRY(begin, NODE, entry);
+        if (IsEOFNode(node))
+            break;
+        if (!first)
+            first = begin;
+        last = begin;
+        if (!(pFC->dwFlags & FLAG_A))
+            PrintLine(pFC, node->lineno, node->pszLine);
+        begin = list_next(list, begin);
+    }
+    if ((pFC->dwFlags & FLAG_A) && first)
+    {
+        node = LIST_ENTRY(first, NODE, entry);
+        PrintLine(pFC, node->lineno, node->pszLine);
+        first = list_next(list, first);
+        if (first != last)
+        {
+            if (list_next(list, first) == last)
+            {
+                node = LIST_ENTRY(first, NODE, entry);
+                PrintLine(pFC, node->lineno, node->pszLine);
+            }
+            else
+            {
+                PrintDots();
+            }
+        }
+        node = LIST_ENTRY(last, NODE, entry);
+        PrintLine(pFC, node->lineno, node->pszLine);
+    }
+}
+
+static VOID
+SkipIdentical(FILECOMPARE *pFC, struct list **pptr0, struct list **pptr1)
+{
+    struct list *ptr0 = *pptr0, *ptr1 = *pptr1;
+    while (ptr0 && ptr1)
+    {
+        NODE *node0 = LIST_ENTRY(ptr0, NODE, entry);
+        NODE *node1 = LIST_ENTRY(ptr1, NODE, entry);
+        if (CompareNode(pFC, node0, node1) != FCRET_IDENTICAL)
+            break;
+        ptr0 = list_next(&pFC->list[0], ptr0);
+        ptr1 = list_next(&pFC->list[1], ptr1);
+    }
+    *pptr0 = ptr0;
+    *pptr1 = ptr1;
+}
+
+static DWORD
+SkipIdenticalN(FILECOMPARE *pFC, struct list **pptr0, struct list **pptr1,
+               DWORD nnnn, DWORD lineno0, DWORD lineno1)
+{
+    struct list *ptr0 = *pptr0, *ptr1 = *pptr1;
+    DWORD count = 0;
+    while (ptr0 && ptr1)
+    {
+        NODE *node0 = LIST_ENTRY(ptr0, NODE, entry);
+        NODE *node1 = LIST_ENTRY(ptr1, NODE, entry);
+        if (node0->lineno >= lineno0)
+            break;
+        if (node1->lineno >= lineno1)
+            break;
+        if (CompareNode(pFC, node0, node1) != FCRET_IDENTICAL)
+            break;
+        ptr0 = list_next(&pFC->list[0], ptr0);
+        ptr1 = list_next(&pFC->list[1], ptr1);
+        ++count;
+        if (count >= nnnn)
+            break;
+    }
+    *pptr0 = ptr0;
+    *pptr1 = ptr1;
+    return count;
+}
+
+static FCRET
+ScanDiff(FILECOMPARE *pFC, struct list **pptr0, struct list **pptr1,
+         DWORD lineno0, DWORD lineno1)
+{
+    struct list *ptr0 = *pptr0, *ptr1 = *pptr1, *tmp0, *tmp1;
+    NODE *node0, *node1;
+    INT count;
+    while (ptr0 && ptr1)
+    {
+        node0 = LIST_ENTRY(ptr0, NODE, entry);
+        node1 = LIST_ENTRY(ptr1, NODE, entry);
+        if (node0->lineno >= lineno0)
+            return FCRET_DIFFERENT;
+        if (node1->lineno >= lineno1)
+            return FCRET_DIFFERENT;
+        tmp0 = ptr0;
+        tmp1 = ptr1;
+        count = SkipIdenticalN(pFC, &tmp0, &tmp1, pFC->nnnn, lineno0,
lineno1);
+        if (count >= pFC->nnnn)
+            break;
+        if (count > 0)
+        {
+            ptr0 = tmp0;
+            ptr1 = tmp1;
+        }
+        else
+        {
+            ptr0 = list_next(&pFC->list[0], ptr0);
+            ptr1 = list_next(&pFC->list[1], ptr1);
+        }
+    }
+    *pptr0 = ptr0;
+    *pptr1 = ptr1;
+    return FCRET_IDENTICAL;
+}
+
+static FCRET
+Resync(FILECOMPARE *pFC, struct list **pptr0, struct list **pptr1)
+{
+    FCRET ret;
+    struct list *ptr0, *ptr1, *save0 = NULL, *save1 = NULL;
+    NODE *node0, *node1;
+    struct list *list0 = &pFC->list[0], *list1 = &pFC->list[1];
+    DWORD lineno0, lineno1;
+    INT penalty, i0, i1, min_penalty = MAXLONG;
+
+    node0 = LIST_ENTRY(*pptr0, NODE, entry);
+    node1 = LIST_ENTRY(*pptr1, NODE, entry);
+    lineno0 = node0->lineno + pFC->n;
+    lineno1 = node1->lineno + pFC->n;
+
+    // ``If the files that you are comparing have more than pFC->n consecutive
+    //   differing lines, FC cancels the comparison,,
+    // ``If the number of matching lines in the files is less than pFC->nnnn,
+    //   FC displays the matching lines as differences,,
+    for (ptr1 = list_next(list1, *pptr1), i1 = 0; ptr1; ptr1 = list_next(list1, ptr1),
++i1)
+    {
+        node1 = LIST_ENTRY(ptr1, NODE, entry);
+        if (node1->lineno >= lineno1)
+            break;
+        for (ptr0 = list_next(list0, *pptr0), i0 = 0; ptr0; ptr0 = list_next(list0,
ptr0), ++i0)
+        {
+            node0 = LIST_ENTRY(ptr0, NODE, entry);
+            if (node0->lineno >= lineno0)
+                break;
+            if (CompareNode(pFC, node0, node1) == FCRET_IDENTICAL)
+            {
+                penalty = min(i0, i1) + abs(i1 - i0);
+                if (min_penalty > penalty)
+                {
+                    min_penalty = penalty;
+                    save0 = ptr0;
+                    save1 = ptr1;
+                }
+            }
+        }
+    }
+
+    if (save0 && save1)
+    {
+        *pptr0 = save0;
+        *pptr1 = save1;
+        ret = ScanDiff(pFC, &save0, &save1, lineno0, lineno1);
+        if (save0 && save1)
+        {
+            *pptr0 = save0;
+            *pptr1 = save1;
+        }
+        return ret;
+    }
+
+    for (ptr0 = *pptr0; ptr0; ptr0 = list_next(list0, ptr0))
+    {
+        node0 = LIST_ENTRY(ptr0, NODE, entry);
+        if (node0->lineno == lineno0)
+            break;
+    }
+    for (ptr1 = *pptr1; ptr1; ptr1 = list_next(list1, ptr1))
+    {
+        node1 = LIST_ENTRY(ptr1, NODE, entry);
+        if (node1->lineno == lineno1)
+            break;
+    }
+    *pptr0 = ptr0;
+    *pptr1 = ptr1;
+    return FCRET_DIFFERENT;
+}
+
+static FCRET 
+Finalize(FILECOMPARE* pFC, struct list *ptr0, struct list* ptr1, BOOL fDifferent)
+{
+    if (!ptr0 || !ptr1)
+    {
+        if (fDifferent)
+            return FCRET_DIFFERENT;
+        return NoDifference();
+    }
+    else
+    {
+        ShowDiff(pFC, 0, ptr0, NULL);
+        ShowDiff(pFC, 1, ptr1, NULL);
+        PrintEndOfDiff();
+        return FCRET_DIFFERENT;
+    }
+}
+
+FCRET TextCompare(FILECOMPARE *pFC, HANDLE *phMapping0, const LARGE_INTEGER *pcb0,
+                                    HANDLE *phMapping1, const LARGE_INTEGER *pcb1)
+{
+    FCRET ret, ret0, ret1;
+    struct list *ptr0, *ptr1, *save0, *save1, *next0, *next1;
+    NODE* node0, * node1;
+    BOOL fDifferent = FALSE;
+    LARGE_INTEGER ib0 = { .QuadPart = 0 }, ib1 = { .QuadPart = 0 };
+    struct list *list0 = &pFC->list[0], *list1 = &pFC->list[1];
+    list_init(list0);
+    list_init(list1);
+
+    do
+    {
+        ret0 = ParseLines(pFC, phMapping0, &ib0, pcb0, list0);
+        if (ret0 == FCRET_INVALID)
+        {
+            ret = ret0;
+            goto cleanup;
+        }
+        ret1 = ParseLines(pFC, phMapping1, &ib1, pcb1, list1);
+        if (ret1 == FCRET_INVALID)
+        {
+            ret = ret1;
+            goto cleanup;
+        }
+
+        ptr0 = list_head(list0);
+        ptr1 = list_head(list1);
+        for (;;)
+        {
+            if (!ptr0 || !ptr1)
+                goto quit;
+
+            // skip identical (sync'ed)
+            SkipIdentical(pFC, &ptr0, &ptr1);
+            if (ptr0 || ptr1)
+                fDifferent = TRUE;
+            node0 = LIST_ENTRY(ptr0, NODE, entry);
+            node1 = LIST_ENTRY(ptr1, NODE, entry);
+            if (IsEOFNode(node0) || IsEOFNode(node1))
+                goto quit;
+
+            // try to resync
+            save0 = ptr0;
+            save1 = ptr1;
+            ret = Resync(pFC, &ptr0, &ptr1);
+            if (ret == FCRET_INVALID)
+                goto cleanup;
+            if (ret == FCRET_DIFFERENT)
+            {
+                // resync failed
+                ret = ResyncFailed();
+                // show the difference
+                ShowDiff(pFC, 0, save0, ptr0);
+                ShowDiff(pFC, 1, save1, ptr1);
+                PrintEndOfDiff();
+                goto cleanup;
+            }
+
+            // show the difference
+            fDifferent = TRUE;
+            next0 = ptr0 ? list_next(list0, ptr0) : ptr0;
+            next1 = ptr1 ? list_next(list1, ptr1) : ptr1;
+            ShowDiff(pFC, 0, save0, (next0 ? next0 : ptr0));
+            ShowDiff(pFC, 1, save1, (next1 ? next1 : ptr1));
+            PrintEndOfDiff();
+
+            // now resync'ed
+        }
+    } while (ret0 != FCRET_NO_MORE_DATA || ret1 != FCRET_NO_MORE_DATA);
+
+quit:
+    ret = Finalize(pFC, ptr0, ptr1, fDifferent);
+cleanup:
+    DeleteList(list0);
+    DeleteList(list1);
+    return ret;
+}
diff --git a/base/applications/cmdutils/fc/texta.c
b/base/applications/cmdutils/fc/texta.c
new file mode 100644
index 00000000000..1f524f76f03
--- /dev/null
+++ b/base/applications/cmdutils/fc/texta.c
@@ -0,0 +1,6 @@
+#undef UNICODE
+#undef _UNICODE
+#ifndef _MBCS
+    #define _MBCS
+#endif
+#include "text.h"
diff --git a/base/applications/cmdutils/fc/textw.c
b/base/applications/cmdutils/fc/textw.c
new file mode 100644
index 00000000000..a3fa9114819
--- /dev/null
+++ b/base/applications/cmdutils/fc/textw.c
@@ -0,0 +1,8 @@
+#ifndef UNICODE
+    #define UNICODE
+#endif
+#ifndef _UNICODE
+    #define _UNICODE
+#endif
+#undef _MBCS
+#include "text.h"