How can we check if a file Exists or not using Win32 program?

Question

How can we check if a file Exists or not using a Win32 program? I am working for a Windows Mobile App.

std::filesystem::exists() C++17 onwards – Sahil Singh Jan 15 '21 at 14:18 — Sahil Singh, Jan 15 '21 at 14:18

score 219 · Answer 1 · edited May 23 '17 at 12:17

219

Use GetFileAttributes to check that the file system object exists and that it is not a directory.

BOOL FileExists(LPCTSTR szPath)
{
  DWORD dwAttrib = GetFileAttributes(szPath);

  return (dwAttrib != INVALID_FILE_ATTRIBUTES && 
         !(dwAttrib & FILE_ATTRIBUTE_DIRECTORY));
}

Copied from How do you check if a directory exists on Windows in C?

edited May 23 '17 at 12:17

Community

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answered Jun 02 '11 at 18:50

Zach Burlingame

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+1 because of a short code example. Code examples are a time saver to get started. – nalply Mar 11 '12 at 14:41
I would like to note that your function returns bool and not BOOL. – Marius Bancila Aug 26 '12 at 20:02
For C++ yes, for C, it's a BOOL – Zach Burlingame Sep 04 '12 at 17:50
Does this also deliver the best performance in file existence checking ? – Bitterblue Apr 05 '13 at 11:51
1

@Bitterblue: Yes, this is as fast as I've been able to find. – Cameron Mar 09 '15 at 16:52
The expression returns bool in C++ so bool return is fine. – paulm Apr 26 '16 at 09:55
2

Although it is possible that `GetFileAttributes()` might return `INVALID_FILE_ATTRIBUTES` due to error conditions other than the file does not exist. – Jonathan Wood Feb 24 '17 at 21:19
"Related"? "Copied from". – MD XF Mar 16 '17 at 20:18

score 38 · Answer 2 · edited Apr 05 '18 at 09:31

38

You can make use of the function GetFileAttributes. It returns 0xFFFFFFFF if the file does not exist.

edited Apr 05 '18 at 09:31

Ajay

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answered Sep 30 '10 at 08:10

codaddict

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Interesting history on GetFileAttributes and why it is the preferred method in Windows code by Raymond Chen: http://blogs.msdn.com/b/oldnewthing/archive/2007/10/23/5612082.aspx – Zach Burlingame Jun 02 '11 at 18:04
2

You need to check for the object being a directory. – David Heffernan Dec 19 '12 at 19:26
9

Actually it returns `INVALID_FILE_ATTRIBUTES` if the file not exists. On 64-bit it could be `0xFFFFFFFFFFFFFFFF`. – Andreas Spindler Apr 09 '13 at 17:14
7

@AndreasSpindler, Since the return type is `DWORD` how it can return `0xFFFFFFFFFFFFFFFF` ? – Ajay Dec 19 '16 at 10:58
Updated link to Raymond Chen's blog: https://devblogs.microsoft.com/oldnewthing/20071023-00/?p=24713 – Ray Jul 25 '20 at 13:42

score 29 · Accepted Answer · edited Oct 15 '15 at 02:33

29

You can call FindFirstFile.

Here is a sample I just knocked up:

#include <windows.h>
#include <tchar.h>
#include <stdio.h>

int fileExists(TCHAR * file)
{
   WIN32_FIND_DATA FindFileData;
   HANDLE handle = FindFirstFile(file, &FindFileData) ;
   int found = handle != INVALID_HANDLE_VALUE;
   if(found) 
   {
       //FindClose(&handle); this will crash
       FindClose(handle);
   }
   return found;
}

void _tmain(int argc, TCHAR *argv[])
{
   if( argc != 2 )
   {
      _tprintf(TEXT("Usage: %s [target_file]\n"), argv[0]);
      return;
   }

   _tprintf (TEXT("Looking for file is %s\n"), argv[1]);

   if (fileExists(argv[1])) 
   {
      _tprintf (TEXT("File %s exists\n"), argv[1]);
   } 
   else 
   {
      _tprintf (TEXT("File %s doesn't exist\n"), argv[1]);
   }
}

edited Oct 15 '15 at 02:33

cdonts

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answered Sep 30 '10 at 08:11

Preet Sangha

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You forgot to call `FindClose`. And you can't return a value from a void function. – David Heffernan Dec 19 '12 at 19:26
4

Half corrected. You need to check for FILE_ATTRIBUTE_DIRECTORY. – David Heffernan Dec 19 '12 at 22:53
2

See other answers for better ways to do this. Also, the code won't even compile as-is due to argv[1] being used in fileExists(); – Christian Aichinger Feb 11 '13 at 14:38
3

Poor solution; `GetFileAttributes()` is much better. – trojanfoe Jul 17 '13 at 15:03
2

`GetFileAttributes` is a one liner – Matt Clarkson Jan 30 '14 at 11:43
4

Suppose `file = "*"`, this might return `true` even if there isn't a file called * – Felix Dombek Feb 28 '14 at 12:43

score 18 · Answer 4 · answered Jan 18 '15 at 15:47

18

How about simply:

#include <io.h>
if(_access(path, 0) == 0)
    ...   // file exists

answered Jan 18 '15 at 15:47

Pierre

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Pierre How did you find this function ? any reference ? – Buddhika Chaturanga Jul 03 '18 at 04:38
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@Buddhika Chaturanga I started using it in Borland Turbo C, back in the 80's. It was the only way to check for the presence of a file, before the fancier "CreateFile". It's buried in the Visual Studio documentation. – Pierre Jul 04 '18 at 12:43

score 9 · Answer 5 · answered Dec 19 '12 at 22:56

9

Another option: 'PathFileExists'.

But I'd probably go with GetFileAttributes.

answered Dec 19 '12 at 22:56

Adrian McCarthy

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In addition `PathFileExists` requires the use of "Shlwapi.dll" (which is unavailable on a few windows versions) and is slightly slower than `GetFileAttributes`. – Bitterblue Apr 05 '13 at 12:45
But it doesn't tell you if a file or directory existed. – Jonathan Wood Feb 24 '17 at 21:19
BTW, PathFileExists is just a wrapper for GetFileAttributes with additional SetErrorMode(SEM_FAILCRITICALERRORS) wrapper. – Alex Sep 09 '19 at 17:17

score 0 · Answer 6 · answered Jul 17 '12 at 04:23

0

You can try to open the file. If it failed, it means not exist in most time.

answered Jul 17 '12 at 04:23

fanzhou

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I'd go with CreateFile -> CloseHandle. easiest and cheapest. – OSH Jun 18 '13 at 19:34
5

A file open can also fail if the files exists but the user does not have sufficient privileges to open the file. These days, that's a **very** common situation. – JackLThornton Apr 15 '16 at 23:39
Not to mention it is not the cheapest because the file can be on a network share which adds latency for each call and with CloseHandle you have two calls instead of one. – Igor Levicki Nov 22 '19 at 10:37

score 0 · Answer 7 · answered Mar 20 '21 at 11:58

Came across the same issue and found this brief code in another forum which uses GetFileAttributes Approach

DWORD dwAttr = GetFileAttributes(szPath);
if (dwAttr == 0xffffffff){

  DWORD dwError = GetLastError();
  if (dwError == ERROR_FILE_NOT_FOUND)
  {
    // file not found
  }
  else if (dwError == ERROR_PATH_NOT_FOUND)
  {
    // path not found
  }
  else if (dwError == ERROR_ACCESS_DENIED)
  {
    // file or directory exists, but access is denied
  }
  else
  {
    // some other error has occured
  }

}else{

  if (dwAttr & FILE_ATTRIBUTE_DIRECTORY)
  {
    // this is a directory
  }
  else
  {
    // this is an ordinary file
  }
}

where szPath is the file-path.

score 0 · Answer 8 · answered Aug 16 '21 at 15:51

Use OpenFile with uStyle = OF_EXIST

if (OpenFile(path, NULL, OF_EXIST) == HFILE_ERROR)
{
    // file not found
}
// file exists, but is not open

Remember, when using OF_EXIST, the file is not open after OpenFile succeeds. Per Win32 documentation:

Value	Meaning
OF_EXIST (0x00004000)	Opens a file and then closes it. Use this to test for the existence of a file.

See doc: https://docs.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-openfile

score -2 · Answer 9 · answered Oct 24 '14 at 13:21

-2

Another more generic non-windows way:

static bool FileExists(const char *path)
{
    FILE *fp;
    fpos_t fsize = 0;

    if ( !fopen_s(&fp, path, "r") )
    {
        fseek(fp, 0, SEEK_END);
        fgetpos(fp, &fsize);
        fclose(fp);
    }

    return fsize > 0;
}

answered Oct 24 '14 at 13:21

Alturis

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if you're going to use fopen et al. you may as well just use `_access(0)`. – Rob K Jun 22 '16 at 14:10
1

@RobK This has the minor advantage of being cross-platform whereas _access is not. The real problem is that it will return that zero-length files don't exist... – Perkins Sep 05 '18 at 19:00
fopen_s is Microsoft specific, and in addition to 0 byte files being declared non-existing by this broken code it also fails on files it can't open (permissions, sharing). – Igor Levicki Nov 22 '19 at 10:39

How can we check if a file Exists or not using Win32 program?

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