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WriteProcessMemory

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This 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, 
LPVOID lpBaseAddress, 
LPVOID lpBuffer, 
DWORD nSize, 
LPDWORD lpNumberOfBytesWritten );

Parameters

  • hProcess
    Handle returned from the OpenProcess function that provided full access to the process.
  • lpBaseAddress
    Pointer 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
    Pointer 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
    Pointer 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

Nonzero indicates success. Zero indicates failure. To get extended error information, call GetLastError. The function fails 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. 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.

Requirements

Runs On Versions Defined in Include Link to
Windows CE OS 2.0 and later Winbase.h   Nk.lib

Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

See Also

OpenProcess, GetLastError, ReadProcessMemory

 Last updated on Tuesday, July 13, 2004

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