擷取快照集、檢視程式
此程式碼範例會擷取執行中的進程清單。 首先, GetProcessList 函式會擷取系統中目前正在執行的進程快照集。 若要這樣做,它會使用 CreateToolhelp32Snapshot 函式,然後逐步解說使用 Process32First 和 Process32Next 記錄在快照集中的清單。 針對每個進程, GetProcessList 會呼叫 ListProcessModules 函式,如周遊模組清單 中所述 ,以及 ListProcessThreads 函 式,如周遊執行緒清單 中所述 。
簡單的錯誤報表函式 printError 會顯示任何失敗的原因(通常是因為安全性限制所致)。 例如, Idle 和 CSRSS 進程的 OpenProcess 失敗,因為其存取限制會防止使用者層級程式碼開啟它們。
若要遵循程式碼範例,請使用 Visual Studio 從 C++ 主控台應用程式 專案範本建立新專案,並將下列程式碼新增至其中。
#include <windows.h>
#include <tlhelp32.h>
#include <tchar.h>
#include <stdio.h>
// Forward declarations:
BOOL GetProcessList( );
BOOL ListProcessModules( DWORD dwPID );
BOOL ListProcessThreads( DWORD dwOwnerPID );
void printError( TCHAR const* msg );
int main( void )
{
GetProcessList( );
return 0;
}
BOOL GetProcessList( )
{
HANDLE hProcessSnap;
HANDLE hProcess;
PROCESSENTRY32 pe32;
DWORD dwPriorityClass;
// Take a snapshot of all processes in the system.
hProcessSnap = CreateToolhelp32Snapshot( TH32CS_SNAPPROCESS, 0 );
if( hProcessSnap == INVALID_HANDLE_VALUE )
{
printError( TEXT("CreateToolhelp32Snapshot (of processes)") );
return( FALSE );
}
// Set the size of the structure before using it.
pe32.dwSize = sizeof( PROCESSENTRY32 );
// Retrieve information about the first process,
// and exit if unsuccessful
if( !Process32First( hProcessSnap, &pe32 ) )
{
printError( TEXT("Process32First") ); // show cause of failure
CloseHandle( hProcessSnap ); // clean the snapshot object
return( FALSE );
}
// Now walk the snapshot of processes, and
// display information about each process in turn
do
{
_tprintf( TEXT("\n\n=====================================================" ));
_tprintf( TEXT("\nPROCESS NAME: %s"), pe32.szExeFile );
_tprintf( TEXT("\n-------------------------------------------------------" ));
// Retrieve the priority class.
dwPriorityClass = 0;
hProcess = OpenProcess( PROCESS_ALL_ACCESS, FALSE, pe32.th32ProcessID );
if( hProcess == NULL )
printError( TEXT("OpenProcess") );
else
{
dwPriorityClass = GetPriorityClass( hProcess );
if( !dwPriorityClass )
printError( TEXT("GetPriorityClass") );
CloseHandle( hProcess );
}
_tprintf( TEXT("\n Process ID = 0x%08X"), pe32.th32ProcessID );
_tprintf( TEXT("\n Thread count = %d"), pe32.cntThreads );
_tprintf( TEXT("\n Parent process ID = 0x%08X"), pe32.th32ParentProcessID );
_tprintf( TEXT("\n Priority base = %d"), pe32.pcPriClassBase );
if( dwPriorityClass )
_tprintf( TEXT("\n Priority class = %d"), dwPriorityClass );
// List the modules and threads associated with this process
ListProcessModules( pe32.th32ProcessID );
ListProcessThreads( pe32.th32ProcessID );
} while( Process32Next( hProcessSnap, &pe32 ) );
CloseHandle( hProcessSnap );
return( TRUE );
}
BOOL ListProcessModules( DWORD dwPID )
{
HANDLE hModuleSnap = INVALID_HANDLE_VALUE;
MODULEENTRY32 me32;
// Take a snapshot of all modules in the specified process.
hModuleSnap = CreateToolhelp32Snapshot( TH32CS_SNAPMODULE, dwPID );
if( hModuleSnap == INVALID_HANDLE_VALUE )
{
printError( TEXT("CreateToolhelp32Snapshot (of modules)") );
return( FALSE );
}
// Set the size of the structure before using it.
me32.dwSize = sizeof( MODULEENTRY32 );
// Retrieve information about the first module,
// and exit if unsuccessful
if( !Module32First( hModuleSnap, &me32 ) )
{
printError( TEXT("Module32First") ); // show cause of failure
CloseHandle( hModuleSnap ); // clean the snapshot object
return( FALSE );
}
// Now walk the module list of the process,
// and display information about each module
do
{
_tprintf( TEXT("\n\n MODULE NAME: %s"), me32.szModule );
_tprintf( TEXT("\n Executable = %s"), me32.szExePath );
_tprintf( TEXT("\n Process ID = 0x%08X"), me32.th32ProcessID );
_tprintf( TEXT("\n Ref count (g) = 0x%04X"), me32.GlblcntUsage );
_tprintf( TEXT("\n Ref count (p) = 0x%04X"), me32.ProccntUsage );
_tprintf( TEXT("\n Base address = 0x%08X"), (DWORD) me32.modBaseAddr );
_tprintf( TEXT("\n Base size = %d"), me32.modBaseSize );
} while( Module32Next( hModuleSnap, &me32 ) );
CloseHandle( hModuleSnap );
return( TRUE );
}
BOOL ListProcessThreads( DWORD dwOwnerPID )
{
HANDLE hThreadSnap = INVALID_HANDLE_VALUE;
THREADENTRY32 te32;
// Take a snapshot of all running threads
hThreadSnap = CreateToolhelp32Snapshot( TH32CS_SNAPTHREAD, 0 );
if( hThreadSnap == INVALID_HANDLE_VALUE )
return( FALSE );
// Fill in the size of the structure before using it.
te32.dwSize = sizeof(THREADENTRY32);
// Retrieve information about the first thread,
// and exit if unsuccessful
if( !Thread32First( hThreadSnap, &te32 ) )
{
printError( TEXT("Thread32First") ); // show cause of failure
CloseHandle( hThreadSnap ); // clean the snapshot object
return( FALSE );
}
// Now walk the thread list of the system,
// and display information about each thread
// associated with the specified process
do
{
if( te32.th32OwnerProcessID == dwOwnerPID )
{
_tprintf( TEXT("\n\n THREAD ID = 0x%08X"), te32.th32ThreadID );
_tprintf( TEXT("\n Base priority = %d"), te32.tpBasePri );
_tprintf( TEXT("\n Delta priority = %d"), te32.tpDeltaPri );
_tprintf( TEXT("\n"));
}
} while( Thread32Next(hThreadSnap, &te32 ) );
CloseHandle( hThreadSnap );
return( TRUE );
}
void printError( TCHAR const* msg )
{
DWORD eNum;
TCHAR sysMsg[256];
TCHAR* p;
eNum = GetLastError( );
FormatMessage( FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
NULL, eNum,
MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
sysMsg, 256, NULL );
// Trim the end of the line and terminate it with a null
p = sysMsg;
while( ( *p > 31 ) || ( *p == 9 ) )
++p;
do { *p-- = 0; } while( ( p >= sysMsg ) &&
( ( *p == '.' ) || ( *p < 33 ) ) );
// Display the message
_tprintf( TEXT("\n WARNING: %s failed with error %d (%s)"), msg, eNum, sysMsg );
}