Win32 File API FindFirstFile function

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Searches a directory for a file or subdirectory with a name that matches a specific name (or partial name if wildcards are used).

Syntax

HANDLE FindFirstFile(    
        LPCWSTR            lpFileName,    
        LPWIN32_FIND_DATAW lpFindFileData  );  

Parameters

lpFileName

The directory or path, and the file name. The file name can include wildcard characters, for example, an asterisk (*) or a question mark (?).

This parameter should not be NULL, an invalid string (for example, an empty string or a string that is missing the terminating null character), or end in a trailing backslash ().

If the string ends with a wildcard, period (.), or directory name, the user must have access permissions to the root and all subdirectories on the path.

In the ANSI version of this function, the name is limited to MAX_PATH characters. To extend this limit to 32,767 wide characters, call the Unicode version of the function and prepend "\?" to the path. For more information, see Naming a File.

lpFindFileData

A pointer to the WIN32_FIND_DATA structure that receives information about a found file or directory.

Return Value

If the function succeeds, the return value is a search handle used in a subsequent call toFindNextFile or FindClose, and the lpFindFileData parameter contains information about the first file or directory found.

If the function fails or fails to locate files from the search string in the lpFileName parameter, the return value is INVALID_HANDLE_VALUE and the contents of lpFindFileData are indeterminate. To get extended error information, call the GetLastError function.

If the function fails because no matching files can be found, the GetLastError function returnsERROR_FILE_NOT_FOUND.

Remarks

The FindFirstFile function opens a search handle and returns information about the first file that the file system finds with a name that matches the specified pattern. This may or may not be the first file or directory that appears in a directory-listing application (such as the dir command) when given the same file name string pattern. This is because FindFirstFile does no sorting of the search results. For additional information, see FindNextFile.

The following list identifies some other search characteristics:

• The search is performed strictly on the name of the file, not on any attributes such as a date or a file type (for other options, see FindFirstFileEx).
• The search includes the long and short file names.
• An attempt to open a search with a trailing backslash always fails.
• Passing an invalid string, NULL, or empty string for the lpFileName parameter is not a valid use of this function. Results in this case are undefined.

After the search handle is established, you can use it to search for other files that match the same pattern by using the FindNextFile function.

When the search handle is no longer needed, close it by using the FindClose function, notCloseHandle.

As stated previously, you cannot use a trailing backslash () in the lpFileName input string for FindFirstFile, therefore it may not be obvious how to search root directories. If you want to see files or get the attributes of a root directory, the following options would apply:

• To examine files in a root directory, you can use "C:\*" and step through the directory by using FindNextFile.
• To get the attributes of a root directory, use the GetFileAttributes function.

On network shares, you can use an lpFileName in the form of the following: "\\Server\Share\*". However, you cannot use an lpFileName that points to the share itself; for example, "\\Server\Share" is not valid.

To examine a directory that is not a root directory, use the path to that directory, without a trailing backslash. For example, an argument of "C:\Windows" returns information about the directory "C:\Windows", not about a directory or file in "C:\Windows". To examine the files and directories in "C:\Windows", use an lpFileName of "C:\Windows*".

Be aware that some other thread or process could create or delete a file with this name between the time you query for the result and the time you act on the information. If this is a potential concern for your application, one possible solution is to use the CreateFile function with CREATE_NEW(which fails if the file exists) or OPEN_EXISTING (which fails if the file does not exist).

If you are writing a 32-bit application to list all the files in a directory and the application may be run on a 64-bit computer, you should call the Wow64DisableWow64FsRedirectionfunction before calling FindFirstFile and call Wow64RevertWow64FsRedirection after the last call to FindNextFile. For more information, see File System Redirector.

If the path points to a symbolic link, the WIN32_FIND_DATA buffer contains information about the symbolic link, not the target.

Examples

The following C++ example shows you a minimal use of FindFirstFile.

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

void _tmain(int argc, TCHAR *argv[])
{
   WIN32_FIND_DATA FindFileData;
   HANDLE hFind;

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

   _tprintf (TEXT("Target file is %s\n"), argv[1]);
   hFind = FindFirstFile(argv[1], &FindFileData);
   if (hFind == INVALID_HANDLE_VALUE) 
   {
      printf ("FindFirstFile failed (%d)\n", GetLastError());
      return;
   } 
   else 
   {
      _tprintf (TEXT("The first file found is %s\n"), 
                FindFileData.cFileName);
      FindClose(hFind);
   }
}