EnumProcessModulesEx function (psapi.h)

Article
10/13/2021

Retrieves a handle for each module in the specified process that meets the specified filter criteria.

Syntax

BOOL EnumProcessModulesEx(
  [in]  HANDLE  hProcess,
  [out] HMODULE *lphModule,
  [in]  DWORD   cb,
  [out] LPDWORD lpcbNeeded,
  [in]  DWORD   dwFilterFlag
);

Parameters

[in] hProcess

A handle to the process.

[out] lphModule

An array that receives the list of module handles.

[in] cb

The size of the lphModule array, in bytes.

[out] lpcbNeeded

The number of bytes required to store all module handles in the lphModule array.

[in] dwFilterFlag

The filter criteria. This parameter can be one of the following values.

Value	Meaning
LIST_MODULES_32BIT 0x01	List the 32-bit modules.
LIST_MODULES_64BIT 0x02	List the 64-bit modules.
LIST_MODULES_ALL 0x03	List all modules.
LIST_MODULES_DEFAULT 0x0	Use the default behavior.

Return value

If the function succeeds, the return value is nonzero.

If the function fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

The EnumProcessModulesEx function is primarily designed for use by debuggers and similar applications that must extract module information from another process. If the module list in the target process is corrupted or not yet initialized, or if the module list changes during the function call as a result of DLLs being loaded or unloaded, EnumProcessModulesEx may fail or return incorrect information.

This function is intended primarily for 64-bit applications. If the function is called by a 32-bit application running under WOW64, the dwFilterFlag option is ignored and the function provides the same results as the EnumProcessModules function.

It is a good idea to specify a large array of HMODULE values, because it is hard to predict how many modules there will be in the process at the time you call EnumProcessModulesEx. To determine if the lphModule array is too small to hold all module handles for the process, compare the value returned in lpcbNeeded with the value specified in cb. If lpcbNeeded is greater than cb, increase the size of the array and call EnumProcessModulesEx again.

To determine how many modules were enumerated by the call to EnumProcessModulesEx, divide the resulting value in the lpcbNeeded parameter by sizeof(HMODULE).

The EnumProcessModulesEx function does not retrieve handles for modules that were loaded with the LOAD_LIBRARY_AS_DATAFILE flag. For more information, see LoadLibraryEx.

Do not call CloseHandle on any of the handles returned by this function. The information comes from a snapshot, so there are no resources to be freed.

To take a snapshot of specified processes and the heaps, modules, and threads used by these processes, use the CreateToolhelp32Snapshot function.

Starting with Windows 7 and Windows Server 2008 R2, Psapi.h establishes version numbers for the PSAPI functions. The PSAPI version number affects the name used to call the function and the library that a program must load.

If PSAPI_VERSION is 2 or greater, this function is defined as K32EnumProcessModulesEx in Psapi.h and exported in Kernel32.lib and Kernel32.dll. If PSAPI_VERSION is 1, this function is defined as EnumProcessModulesEx in Psapi.h and exported in Psapi.lib and Psapi.dll as a wrapper that calls K32EnumProcessModulesEx.

Programs that must run on earlier versions of Windows as well as Windows 7 and later versions should always call this function as EnumProcessModulesEx. To ensure correct resolution of symbols, add Psapi.lib to the TARGETLIBS macro and compile the program with –DPSAPI_VERSION=1. To use run-time dynamic linking, load Psapi.dll.

Requirements

Requirement	Value
Minimum supported client	Windows Vista [desktop apps only]
Minimum supported server	Windows Server 2008 [desktop apps only]
Target Platform	Windows
Header	psapi.h (include Windows.h)
Library	Kernel32.lib on Windows 7 and Windows Server 2008 R2; Psapi.lib (if PSAPI_VERSION=1) on Windows 7 and Windows Server 2008 R2; Psapi.lib on Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP
DLL	Kernel32.dll on Windows 7 and Windows Server 2008 R2; Psapi.dll (if PSAPI_VERSION=1) on Windows 7 and Windows Server 2008 R2; Psapi.dll on Windows Server 2008, Windows Vista, Windows Server 2003 and Windows XP