Win API- Learn Item1

EnumProcesses Function

Retrieves the process identifier for each process object in the system.

Syntax

BOOL WINAPI EnumProcesses(
  __out  DWORD *pProcessIds,
  __in   DWORD cb,
  __out  DWORD *pBytesReturned
);

Parameters

pProcessIds [out]

A pointer to an array that receives the list of process identifiers.

cb [in]

The size of the pProcessIds array, in bytes.

pBytesReturned [out]

The number of bytes returned in the pProcessIds array.

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.

Requirements

Minimum supported client	Windows 2000 Professional
Minimum supported server	Windows 2000 Server
Header	Psapi.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/2000
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/2000

GetModuleBaseName Function Retrieves the base name of the specified module. Syntax DWORD WINAPI GetModuleBaseName( __in      HANDLE hProcess, __in_opt  HMODULE hModule, __out     LPTSTR lpBaseName, __in      DWORD nSize ); Parameters hProcess [in] A handle to the process that contains the module. The handle must have the PROCESS_QUERY_INFORMATION and PROCESS_VM_READ access rights. For more information, see Process Security and Access Rights. hModule [in, optional] A handle to the module. If this parameter is NULL, this function returns the name of the file used to create the calling process. lpBaseName [out] A pointer to the buffer that receives the base name of the module. If the base name is longer than maximum number of characters specified by the nSize parameter, the base name is truncated. nSize [in] The size of the lpBaseName buffer, in characters. Return Value If the function succeeds, the return value specifies the length of the string copied to the buffer, in characters. If the function fails, the return value is zero. To get extended error information, call GetLastError. OpenProcess Function Opens an existing local process object. Syntax Copy HANDLE WINAPI OpenProcess( __in  DWORD dwDesiredAccess, __in  BOOL bInheritHandle, __in  DWORD dwProcessId ); Parameters dwDesiredAccess [in] The access to the process object. This access right is checked against the security descriptor for the process. This parameter can be one or more of the process access rights. If the caller has enabled the SeDebugPrivilege privilege, the requested access is granted regardless of the contents of the security descriptor. bInheritHandle [in] If this value is TRUE, processes created by this process will inherit the handle. Otherwise, the processes do not inherit this handle. dwProcessId [in] The identifier of the local process to be opened. If the specified process is the System Process (0x00000000), the function fails and the last error code is ERROR_INVALID_PARAMETER. If the specified process is the Idle process or one of the CSRSS processes, this function fails and the last error code is ERROR_ACCESS_DENIED because their access restrictions prevent user-level code from opening them. Return Value If the function succeeds, the return value is an open handle to the specified process. If the function fails, the return value is NULL. To get extended error information, call GetLastError. Sample: HANDLE h = ::OpenProcess(PROCESS_QUERY_INFORMATION | PROCESS_VM_READ, FALSE, pid);