Create Unique File Name in Windows
Jump to navigation
Jump to search
Example
* See : http://msdn.microsoft.com/en-us/library/aa363875(VS.85).aspx
#include <windows.h> #include <tchar.h> #include <stdio.h> #define BUFSIZE 512 int _tmain(int argc, TCHAR *argv[]) { HANDLE hFile; HANDLE hTempFile; DWORD dwRetVal; DWORD dwBytesRead; DWORD dwBytesWritten; DWORD dwBufSize=BUFSIZE; UINT uRetVal; TCHAR szTempName[BUFSIZE]; char buffer[BUFSIZE]; TCHAR lpPathBuffer[BUFSIZE]; BOOL fSuccess; if(argc != 2) { _tprintf(TEXT("Usage: %s <file>\n"), argv[0]); return -1; } // Open the existing file. hFile = CreateFile(argv[1], // file name GENERIC_READ, // open for reading 0, // do not share NULL, // default security OPEN_EXISTING, // existing file only FILE_ATTRIBUTE_NORMAL, // normal file NULL); // no template if (hFile == INVALID_HANDLE_VALUE) { printf ("First CreateFile failed (%d)\n", GetLastError()); return (1); } // Get the temp path. dwRetVal = GetTempPath(dwBufSize, // length of the buffer lpPathBuffer); // buffer for path if (dwRetVal > dwBufSize || (dwRetVal == 0)) { printf ("GetTempPath failed (%d)\n", GetLastError()); return (2); } // Create a temporary file. uRetVal = GetTempFileName(lpPathBuffer, // directory for tmp files TEXT("NEW"), // temp file name prefix 0, // create unique name szTempName); // buffer for name if (uRetVal == 0) { printf ("GetTempFileName failed (%d)\n", GetLastError()); return (3); } // Create the new file to write the upper-case version to. hTempFile = CreateFile((LPTSTR) szTempName, // file name GENERIC_READ | GENERIC_WRITE, // open r-w 0, // do not share NULL, // default security CREATE_ALWAYS, // overwrite existing FILE_ATTRIBUTE_NORMAL,// normal file NULL); // no template if (hTempFile == INVALID_HANDLE_VALUE) { printf ("Second CreateFile failed (%d)\n", GetLastError()); return (4); } // Read BUFSIZE blocks to the buffer. Change all characters in // the buffer to upper case. Write the buffer to the temporary // file. do { if (ReadFile(hFile, buffer, BUFSIZE, &dwBytesRead, NULL)) { CharUpperBuffA(buffer, dwBytesRead); fSuccess = WriteFile(hTempFile, buffer, dwBytesRead, &dwBytesWritten, NULL); if (!fSuccess) { printf ("WriteFile failed (%d)\n", GetLastError()); return (5); } } else { printf ("ReadFile failed (%d)\n", GetLastError()); return (6); } } while (dwBytesRead == BUFSIZE); // Close the handles to the files. fSuccess = CloseHandle (hFile); if (!fSuccess) { printf ("CloseHandle failed (%d)\n", GetLastError()); return (7); } fSuccess = CloseHandle (hTempFile); if (!fSuccess) { printf ("CloseHandle failed (%d)\n", GetLastError()); return (8); } // Move the temporary file to the new text file. fSuccess = MoveFileEx(szTempName, TEXT("Allcaps.txt"), MOVEFILE_REPLACE_EXISTING); if (!fSuccess) { printf ("MoveFileEx failed (%d)\n", GetLastError()); return (9); } else _tprintf(TEXT("All caps version of %s written to Allcaps.txt\n"), argv[1]); return (0); }