WriteProcessMemory
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 |
|
); |
|
Parameters
hProcess
Identifies an
open handle to a process whose memory is to be written to. The handle must have
PROCESS_VM_WRITE and PROCESS_VM_OPERATION access to the process.
lpBaseAddress
Points to the
base address in the specified process to be written to. Before any data
transfer occurs, the system verifies that all data in the base address and
memory of the specified size is accessible for write access. If this is the
case, the function proceeds; otherwise, the function fails.
lpBuffer
Points to the
buffer that supplies data to be written into the address space of the specified
process.
nSize
Specifies the
requested number of bytes to write into the specified process.
lpNumberOfBytesWritten
Points to the
actual number of bytes transferred into the specified process. This parameter
is optional. If lpNumberOfBytesWritten is NULL, the parameter is
ignored.
Return Values
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.
Remarks
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.
See Also