This function obtains information about the entries in the Window List.

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

HAB         hab;          /*  Anchor-block handle. */
PSWBLOCK    pswblkBlock;  /*  Switch entries block. */
ULONG       ulLength;     /*  Maximum length of data returnable in bytes. */
ULONG       ulCount;      /*  Total number of switch list entries present in the system. */

ulCount = WinQuerySwitchList(hab, pswblkBlock,
            ulLength);