Microsoft Docs

CloseHandle

Function Closes an open object handle.

Syntax

BOOL CloseHandle(
    HANDLE hObject
);

Parameters

Return Value

If the function succeeds, the return value is nonzero. If it fails, the return value is zero. To get extended error information, call GetLastError.

Remarks

• Do not use a handle after it has been closed.
• Closing a handle does not necessarily close the underlying resource if other handles refer to it.
• For console handles, use FreeConsole instead of CloseHandle.
• When the last handle to a kernel object is closed, the system destroys the object.

Example

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

int main(void) {
    HANDLE hFile = CreateFileA(
        "example.txt",
        GENERIC_READ,
        0,
        NULL,
        OPEN_EXISTING,
        FILE_ATTRIBUTE_NORMAL,
        NULL);

    if (hFile == INVALID_HANDLE_VALUE) {
        printf("CreateFile failed (error %lu)\\n", GetLastError());
        return 1;
    }

    // Perform I/O operations...

    if (!CloseHandle(hFile)) {
        printf("CloseHandle failed (error %lu)\\n", GetLastError());
        return 1;
    }

    printf("File closed successfully.\\n");
    return 0;
}

See Also

• CreateFile
• CreateEvent
• OpenProcess
• GetLastError