Provides more information about return values that have been received from other control-program functions.

#define INCL_DOSMISC
#include <os2.h>

ULONG     code;     /*  A nonzero return value returned by a control-program function. */
PULONG    pClass;   /*  A pointer to the ULONG in which the classification for the error is returned. */
PULONG    pAction;  /*  A pointer to the ULONG in which the recommended corrective action for the error is returned. */
PULONG    pLocus;   /*  A pointer to the ULONG in which the error origination is returned. */
APIRET    ulrc;     /*  Return Code. */

ulrc = DosErrClass(code, pClass, pAction,
         pLocus);