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MyFSD_FindFirstFileW (Compact 2013)

  • Artigo

3/26/2014

This function searches a directory for a file with the specified name in an installable file system. This function examines subdirectory, names as well as file names. The application does not call this function directly. Instead, it uses the corresponding standard Win32 function FindFirstFile. The File Ssystem Disk Manager (FSDMGR) determines the file system type and calls the MyFSD_FindFirstFileW implementation of the function.

Syntax

HANDLE MyFSD_FindFirstFileW( 
  PVOLUME pVolume, 
  HANDLE hProc,
  PCWSTR pwsFileSpec, 
  PWIN32_FIND_DATAW pfd
);

Parameters

  • pVolume
    [in] Pointer to the value that a file system driver (FSD) passes to the FSDMGR_RegisterVolume function when it creates the file handle.
  • hProc
    [in] Handle of the process that calls FindFirstFile.

  • pwsFileSpec
    [in] Pointer to a null-terminated string that specifies a valid directory or path and file name, which can contain wildcard characters, such as the asterisk (*) and question mark (?).

    There is a default string size limit for paths of MAX_PATH characters. This limit is related to how the FindFirstFile function parses paths.

  • pfd
    [out] Pointer to the WIN32_FIND_DATA structure that receives information about the found file or subdirectory.

Return Value

A search handle used in a subsequent call to the MyFSD_FindNextFileW or the MyFSD_FindClose indicates success. INVALID_HANDLE_VALUE indicates failure. To get extended error information, call GetLastError.

Remarks

This function opens a search handle and returns information about the first file with the specified name. Once the search handle is established, the **MyFSD_FindNextFileW function searches for other files with the same name. When the search handle is no longer needed, close it by using the **MyFSD_FindClose function.

This function searches for files by name only. It cannot be used for attribute-based searches.

An FSD exports this function, if it supports the FindFirstFile function. All FSD functions can be called on re-entry. Therefore, take this into account when developing an FSD.

FSDMGR is a DLL that manages all OS interaction with installable files systems. Each installable file system requires an FSD, which is a DLL that supports an installable file system. The name of the DLL for an FSD and the names of the functions it exports start with the name of the associated installable file system. For example, if the name of file system is MyFSD, its DLL is MyFSD.dll, and its exported functions are prefaced with MyFSD_*.

FSDMGR provides service functions to FSDs. The FSDMGR_RegisterVolume, the FSDMGR_CreateFileHandle, and the FSDMGR_CreateSearchHandle functions record a DWORD of volume-specific data that an FSD associates with a volume. This volume-specific data is passed as the first parameter of these three functions.

Applications that access an installable file system use standard Win32 functions. For example, when an application wants to create a folder on a device that contains an installable file system, it calls the CreateDirectory function. FSDMGR recognizes that the path is to a device containing an installable file system and calls the appropriate function, which in the case of the MyFSD file system is MyFSD_CreateDirectoryW. That is, the application calls CreateDirectory, causing FSDMGR to call **MyFSD_CreateDirectoryW.

Requirements

Header

fsdmgr.h

Library

Fsdmgr.lib

See Also

Reference

MyFSD Functions
CreateDirectory
FindFirstFile
FindClose
FindNextFile
FSDMGR_CreateFileHandle
FSDMGR_CreateSearchHandle
FSDMGR_RegisterVolume
MyFSD_CreateDirectoryW
MyFSD_FindClose
MyFSD_FindNextFileW
WIN32_FIND_DATA