This function returns the state (enabled/disabled) of physical input.

#define INCL_WININPUT /* Or use INCL_WIN, INCL_PM, */
#include <os2.h>

HWND    hwndDeskTop;  /*  Desktop-window handle. */
BOOL    rc;           /*  Enabled-state indicator. */

rc = WinIsPhysInputEnabled(hwndDeskTop);