他のプロセスのコマンドラインを取得

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

#define ProcessBasicInformation 0

typedef struct
{
    USHORT Length;
    USHORT MaximumLength;
    PWSTR  Buffer;
} UNICODE_STRING, *PUNICODE_STRING;

typedef struct
{
    ULONG          AllocationSize;
    ULONG          ActualSize;
    ULONG          Flags;
    ULONG          Unknown1;
    UNICODE_STRING Unknown2;
    HANDLE         InputHandle;
    HANDLE         OutputHandle;
    HANDLE         ErrorHandle;
    UNICODE_STRING CurrentDirectory;
    HANDLE         CurrentDirectoryHandle;
    UNICODE_STRING SearchPaths;
    UNICODE_STRING ApplicationName;
    UNICODE_STRING CommandLine;
    PVOID          EnvironmentBlock;
    ULONG          Unknown[9];
    UNICODE_STRING Unknown3;
    UNICODE_STRING Unknown4;
    UNICODE_STRING Unknown5;
    UNICODE_STRING Unknown6;
} PROCESS_PARAMETERS, *PPROCESS_PARAMETERS;

typedef struct
{
    ULONG               AllocationSize;
    ULONG               Unknown1;
    HINSTANCE           ProcessHinstance;
    PVOID               ListDlls;
    PPROCESS_PARAMETERS ProcessParameters;
    ULONG               Unknown2;
    HANDLE              Heap;
} PEB, *PPEB;

typedef struct
{
    DWORD ExitStatus;
    PPEB  PebBaseAddress;
    DWORD AffinityMask;
    DWORD BasePriority;
    ULONG UniqueProcessId;
    ULONG InheritedFromUniqueProcessId;
}   PROCESS_BASIC_INFORMATION;

// ntdll!NtQueryInformationProcess (NT specific!)
//
// The function copies the process information of the
// specified type into a buffer
//
// NTSYSAPI
// NTSTATUS
// NTAPI
// NtQueryInformationProcess(
//    IN HANDLE ProcessHandle,              // handle to process
//    IN PROCESSINFOCLASS InformationClass, // information type
//    OUT PVOID ProcessInformation,         // pointer to buffer
//    IN ULONG ProcessInformationLength,    // buffer size in bytes
//    OUT PULONG ReturnLength OPTIONAL      // pointer to a 32-bit
//                                          // variable that receives
//                                          // the number of bytes
//                                          // written to the buffer 
// );
typedef LONG (WINAPI *PROCNTQSIP)(HANDLE,UINT,PVOID,ULONG,PULONG);

PROCNTQSIP NtQueryInformationProcess;

BOOL GetProcessCmdLine(DWORD dwId,LPWSTR wBuf,DWORD dwBufLen);

void main(int argc, char* argv[])
{
    if (argc<2)
    {
        printf("Usage:

cmdline.exe ProcId
");
        return;
    }

    NtQueryInformationProcess = (PROCNTQSIP)GetProcAddress(
        GetModuleHandleA("ntdll"),
        "NtQueryInformationProcess"
        );

    if (!NtQueryInformationProcess)
        return;

    DWORD dwId;
    sscanf(argv[1],"%lu",&dwId);

    WCHAR wstr[255] = {0};

    if (GetProcessCmdLine(dwId,wstr,sizeof(wstr)))
        wprintf(L"Command line for process %lu is:
%s
",dwId,wstr);
    else
        wprintf(L"Could not get command line!");
    system("pause");
}

BOOL GetProcessCmdLine(DWORD dwId,LPWSTR wBuf,DWORD dwBufLen)
{
    LONG                      status;
    HANDLE                    hProcess;
    PROCESS_BASIC_INFORMATION pbi;
    PEB                       Peb;
    PROCESS_PARAMETERS        ProcParam;
    DWORD                     dwDummy;
    DWORD                     dwSize;
    LPVOID                    lpAddress;
    BOOL                      bRet = FALSE;

    // Get process handle
    hProcess = OpenProcess(PROCESS_QUERY_INFORMATION|PROCESS_VM_READ,FALSE,dwId);
    if (!hProcess)
        return FALSE;

    // Retrieve information
    status = NtQueryInformationProcess( hProcess,
        ProcessBasicInformation,
        (PVOID)&pbi,
        sizeof(PROCESS_BASIC_INFORMATION),
        NULL
        );

    if (status)
        goto cleanup;

    if (!ReadProcessMemory( hProcess,
        pbi.PebBaseAddress,
        &Peb,
        sizeof(PEB),
        &dwDummy
        )
        )
        goto cleanup;

    if (!ReadProcessMemory( hProcess,
        Peb.ProcessParameters,
        &ProcParam,
        sizeof(PROCESS_PARAMETERS),
        &dwDummy
        )
        )
        goto cleanup;

    lpAddress = ProcParam.CommandLine.Buffer;
    dwSize = ProcParam.CommandLine.Length;

    if (dwBufLen<dwSize)
        goto cleanup;

    if (!ReadProcessMemory( hProcess,
        lpAddress,
        wBuf,
        dwSize,
        &dwDummy
        )
        )
        goto cleanup;

    bRet = TRUE;

cleanup:

    CloseHandle (hProcess);


    return bRet;
    
}