create win32::is_same_file()

nu774 · May 5, 2017 · c3a0a7e · c3a0a7e
1 parent b7c8e56
commit c3a0a7e
Show file tree

Hide file tree

Showing 3 changed files with 19 additions and 8 deletions.
diff --git a/main.cpp b/main.cpp
@@ -152,14 +152,7 @@ std::wstring get_output_filename(const wchar_t *ifilename, const Options &opts)
     } catch (...) {
         return ofilename;
     }
-    BY_HANDLE_FILE_INFORMATION ibhi = { 0 }, obhi = { 0 };
-    HANDLE ih = reinterpret_cast<HANDLE>(_get_osfhandle(fileno(ifp.get())));
-    HANDLE oh = reinterpret_cast<HANDLE>(_get_osfhandle(fileno(ofp.get())));
-    GetFileInformationByHandle(ih, &ibhi);
-    GetFileInformationByHandle(oh, &obhi);
-    if (ibhi.dwVolumeSerialNumber != obhi.dwVolumeSerialNumber ||
-        ibhi.nFileIndexHigh != obhi.nFileIndexHigh ||
-        ibhi.nFileIndexLow != obhi.nFileIndexLow)
+    if (!win32::is_same_file(_fileno(ifp.get()), _fileno(ofp.get())))
         return ofilename;
 
     std::wstring tl = strutil::format(L"_%s", ext);

diff --git a/win32util.cpp b/win32util.cpp
@@ -123,4 +123,15 @@ namespace win32 {
         }
         return "";
     }
+
+    bool is_same_file(HANDLE ha, HANDLE hb)
+    {
+        BY_HANDLE_FILE_INFORMATION bhfia, bhfib;
+
+        if (!GetFileInformationByHandle(ha, &bhfia)) return false;
+        if (!GetFileInformationByHandle(hb, &bhfib)) return false;
+        return bhfia.dwVolumeSerialNumber == bhfib.dwVolumeSerialNumber
+            && bhfia.nFileIndexHigh == bhfib.nFileIndexHigh
+            && bhfia.nFileIndexLow == bhfib.nFileIndexLow;
+    }
 }
diff --git a/win32util.h b/win32util.h
@@ -143,5 +143,12 @@ namespace win32 {
     int create_named_pipe(const wchar_t *path);
 
     std::string get_dll_version_for_locale(HMODULE hDll, WORD langid);
+
+    bool is_same_file(HANDLE ha, HANDLE hb);
+
+    inline bool is_same_file(int fda, int fdb)
+    {
+        return is_same_file(get_handle(fda), get_handle(fdb));
+    }
 }
 #endif