MSDN:Enumerating All Processes Task Manager is an example of a program that enumerates all running processes. It is implemented using data from the performance registry. The following sample code uses the EnumProcesses function to enumerate the current processes in the system. This method is easier than using the performance registry.#include <windows.h> #include <stdio.h> #include <tchar.h> #include "psapi.h"void PrintProcessNameAndID( DWORD processID ) { TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>"); // Get a handle to the process. HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID ); // Get the process name. if (NULL != hProcess ) { HMODULE hMod; DWORD cbNeeded; if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod), &cbNeeded) ) { GetModuleBaseName( hProcess, hMod, szProcessName, sizeof(szProcessName)/sizeof(TCHAR) ); } } // Print the process name and identifier. _tprintf( TEXT("%s (PID: %u)\n"), szProcessName, processID ); CloseHandle( hProcess ); }void main( ) { // Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses; unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the name and process identifier for each process. for ( i = 0; i < cProcesses; i++ ) PrintProcessNameAndID( aProcesses[i] ); }
Enumerating All Modules For a Process To determine which processes have loaded a particular DLL, you must enumerate the modules for each process. The following sample code uses the EnumProcessModules function to enumerate the modules of current processes in the system.#include <windows.h> #include <stdio.h> #include "psapi.h"void PrintModules( DWORD processID ) { HMODULE hMods[1024]; HANDLE hProcess; DWORD cbNeeded; unsigned int i; // Print the process identifier. printf( "\nProcess ID: %u\n", processID ); // Get a list of all the modules in this process. hProcess = OpenProcess( PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID ); if (NULL == hProcess) return; if( EnumProcessModules(hProcess, hMods, sizeof(hMods), &cbNeeded)) { for ( i = 0; i < (cbNeeded / sizeof(HMODULE)); i++ ) { char szModName[MAX_PATH]; // Get the full path to the module's file. if ( GetModuleFileNameEx( hProcess, hMods[i], szModName, sizeof(szModName))) { // Print the module name and handle value. printf("\t%s (0x%08X)\n", szModName, hMods[i] ); } } } CloseHandle( hProcess ); }void main( ) { // Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses; unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the name of the modules for each process. for ( i = 0; i < cProcesses; i++ ) PrintModules( aProcesses[i] ); }The main function obtains a list of processes by using the EnumProcesses function. For each process, the main function calls the PrintModules function, passing it the process identifier. PrintModules in turn calls the OpenProcess function to obtain the process handle. If OpenProcess fails, the output shows only the process identifier. For example, OpenProcess fails for the Idle and CSRSS processes because their access restrictions prevent user-level code from opening them. Next, PrintModules calls the EnumProcessModules function to obtain the module handles function. Finally, PrintModules calls the GetModuleFileNameEx function, once for each module, to obtain the module names.
Platform SDK: Performance Monitoring Collecting Memory Usage Information For a Process To determine the efficiency of your application, you may want to examine its memory usage. The following sample code uses the GetProcessMemoryInfo function to obtain information about the memory usage of a process.#include <windows.h> #include <stdio.h> #include "psapi.h"void PrintMemoryInfo( DWORD processID ) { HANDLE hProcess; PROCESS_MEMORY_COUNTERS pmc; // Print the process identifier. printf( "\nProcess ID: %u\n", processID ); // Print information about the memory usage of the process. hProcess = OpenProcess( PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, processID ); if (NULL == hProcess) return; if ( GetProcessMemoryInfo( hProcess, &pmc, sizeof(pmc)) ) { printf( "\tPageFaultCount: 0x%08X\n", pmc.PageFaultCount ); printf( "\tPeakWorkingSetSize: 0x%08X\n", pmc.PeakWorkingSetSize ); printf( "\tWorkingSetSize: 0x%08X\n", pmc.WorkingSetSize ); printf( "\tQuotaPeakPagedPoolUsage: 0x%08X\n", pmc.QuotaPeakPagedPoolUsage ); printf( "\tQuotaPagedPoolUsage: 0x%08X\n", pmc.QuotaPagedPoolUsage ); printf( "\tQuotaPeakNonPagedPoolUsage: 0x%08X\n", pmc.QuotaPeakNonPagedPoolUsage ); printf( "\tQuotaNonPagedPoolUsage: 0x%08X\n", pmc.QuotaNonPagedPoolUsage ); printf( "\tPagefileUsage: 0x%08X\n", pmc.PagefileUsage ); printf( "\tPeakPagefileUsage: 0x%08X\n", pmc.PeakPagefileUsage ); } CloseHandle( hProcess ); }void main( ) { // Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses; unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) ) return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the memory usage for each process for ( i = 0; i < cProcesses; i++ ) PrintMemoryInfo( aProcesses[i] ); }The main function obtains a list of processes by using the EnumProcesses function. For each process, main calls the PrintMemoryInfo function, passing the process identifier. PrintMemoryInfo in turn calls the OpenProcess function to obtain the process handle. If OpenProcess fails, the output shows only the process identifier. For example, OpenProcess fails for the Idle and CSRSS processes because their access restrictions prevent user-level code from opening them. Finally, PrintMemoryInfo calls the GetProcessMemoryInfo function to obtain the memory usage information.
Task Manager is an example of a program that enumerates all running processes. It is implemented using data from the performance registry. The following sample code uses the EnumProcesses function to enumerate the current processes in the system. This method is easier than using the performance registry.#include <windows.h>
#include <stdio.h>
#include <tchar.h>
#include "psapi.h"void PrintProcessNameAndID( DWORD processID )
{
TCHAR szProcessName[MAX_PATH] = TEXT("<unknown>"); // Get a handle to the process. HANDLE hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID ); // Get the process name. if (NULL != hProcess )
{
HMODULE hMod;
DWORD cbNeeded; if ( EnumProcessModules( hProcess, &hMod, sizeof(hMod),
&cbNeeded) )
{
GetModuleBaseName( hProcess, hMod, szProcessName,
sizeof(szProcessName)/sizeof(TCHAR) );
}
} // Print the process name and identifier. _tprintf( TEXT("%s (PID: %u)\n"), szProcessName, processID ); CloseHandle( hProcess );
}void main( )
{
// Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses;
unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) )
return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the name and process identifier for each process. for ( i = 0; i < cProcesses; i++ )
PrintProcessNameAndID( aProcesses[i] );
}
To determine which processes have loaded a particular DLL, you must enumerate the modules for each process. The following sample code uses the EnumProcessModules function to enumerate the modules of current processes in the system.#include <windows.h>
#include <stdio.h>
#include "psapi.h"void PrintModules( DWORD processID )
{
HMODULE hMods[1024];
HANDLE hProcess;
DWORD cbNeeded;
unsigned int i; // Print the process identifier. printf( "\nProcess ID: %u\n", processID ); // Get a list of all the modules in this process. hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID );
if (NULL == hProcess)
return; if( EnumProcessModules(hProcess, hMods, sizeof(hMods), &cbNeeded))
{
for ( i = 0; i < (cbNeeded / sizeof(HMODULE)); i++ )
{
char szModName[MAX_PATH]; // Get the full path to the module's file. if ( GetModuleFileNameEx( hProcess, hMods[i], szModName,
sizeof(szModName)))
{
// Print the module name and handle value. printf("\t%s (0x%08X)\n", szModName, hMods[i] );
}
}
} CloseHandle( hProcess );
}void main( )
{
// Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses;
unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) )
return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the name of the modules for each process. for ( i = 0; i < cProcesses; i++ )
PrintModules( aProcesses[i] );
}The main function obtains a list of processes by using the EnumProcesses function. For each process, the main function calls the PrintModules function, passing it the process identifier. PrintModules in turn calls the OpenProcess function to obtain the process handle. If OpenProcess fails, the output shows only the process identifier. For example, OpenProcess fails for the Idle and CSRSS processes because their access restrictions prevent user-level code from opening them. Next, PrintModules calls the EnumProcessModules function to obtain the module handles function. Finally, PrintModules calls the GetModuleFileNameEx function, once for each module, to obtain the module names.
Platform SDK: Performance Monitoring
Collecting Memory Usage Information For a Process
To determine the efficiency of your application, you may want to examine its memory usage. The following sample code uses the GetProcessMemoryInfo function to obtain information about the memory usage of a process.#include <windows.h>
#include <stdio.h>
#include "psapi.h"void PrintMemoryInfo( DWORD processID )
{
HANDLE hProcess;
PROCESS_MEMORY_COUNTERS pmc; // Print the process identifier. printf( "\nProcess ID: %u\n", processID ); // Print information about the memory usage of the process. hProcess = OpenProcess( PROCESS_QUERY_INFORMATION |
PROCESS_VM_READ,
FALSE, processID );
if (NULL == hProcess)
return; if ( GetProcessMemoryInfo( hProcess, &pmc, sizeof(pmc)) )
{
printf( "\tPageFaultCount: 0x%08X\n", pmc.PageFaultCount );
printf( "\tPeakWorkingSetSize: 0x%08X\n",
pmc.PeakWorkingSetSize );
printf( "\tWorkingSetSize: 0x%08X\n", pmc.WorkingSetSize );
printf( "\tQuotaPeakPagedPoolUsage: 0x%08X\n",
pmc.QuotaPeakPagedPoolUsage );
printf( "\tQuotaPagedPoolUsage: 0x%08X\n",
pmc.QuotaPagedPoolUsage );
printf( "\tQuotaPeakNonPagedPoolUsage: 0x%08X\n",
pmc.QuotaPeakNonPagedPoolUsage );
printf( "\tQuotaNonPagedPoolUsage: 0x%08X\n",
pmc.QuotaNonPagedPoolUsage );
printf( "\tPagefileUsage: 0x%08X\n", pmc.PagefileUsage );
printf( "\tPeakPagefileUsage: 0x%08X\n",
pmc.PeakPagefileUsage );
} CloseHandle( hProcess );
}void main( )
{
// Get the list of process identifiers. DWORD aProcesses[1024], cbNeeded, cProcesses;
unsigned int i; if ( !EnumProcesses( aProcesses, sizeof(aProcesses), &cbNeeded ) )
return; // Calculate how many process identifiers were returned. cProcesses = cbNeeded / sizeof(DWORD); // Print the memory usage for each process for ( i = 0; i < cProcesses; i++ )
PrintMemoryInfo( aProcesses[i] );
}The main function obtains a list of processes by using the EnumProcesses function. For each process, main calls the PrintMemoryInfo function, passing the process identifier. PrintMemoryInfo in turn calls the OpenProcess function to obtain the process handle. If OpenProcess fails, the output shows only the process identifier. For example, OpenProcess fails for the Idle and CSRSS processes because their access restrictions prevent user-level code from opening them. Finally, PrintMemoryInfo calls the GetProcessMemoryInfo function to obtain the memory usage information.