The WriteProcessMemory function writes memory in a specified process. The entire area to be written to must be accessible, or the operation fails.
BOOL WriteProcessMemory(
HANDLE hProcess, // handle to process whose memory is written to
LPVOID lpBaseAddress,
// address to start writing to
LPVOID lpBuffer, // pointer to buffer to write data to
DWORD nSize, // number of bytes to write
LPDWORD lpNumberOfBytesWritten
// actual number of bytes written
);
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. The function will fail if the requested write operation crosses into an area of the process that is inaccessible.
WriteProcessMemory copies the data from the specified buffer in the current process to the address range of the specified process. Any process that has a handle with PROCESS_VM_WRITE and PROCESS_VM_OPERATION access to the process to be written to can call the function. The process whose address space is being written to is typically, but not necessarily, being debugged.
The entire area to be written to must be accessible. If it is not, the function fails as noted previously.
Windows CE: The hProcess parameter is the handle returned from the OpenProcess function that provided full access to the process.
Windows NT: Requires version 3.1 or later.
Windows: Requires Windows 95 or later.
Windows CE: Unsupported.
Header: Declared in winbase.h.
Import Library: Use kernel32.lib.
Debugging Overview, Debugging Functions, ReadProcessMemory, WriteProcessMemoryVlm