This example shoes how to post an event semaphore with this API.

 #define INCL_DOSSEMAPHORES   /* Semaphore values */
 #define INCL_DOSERRORS       /* DOS error values */
 #include <os2.h>
 #include <stdio.h>

 int main(VOID) {

 PSZ     szSemName  = "\\SEM32\\MYTOOL\\EVENTSEM\\1"; /* Semaphore name    */
 HEV     hevEvent      = 0;                   /* Event semaphore handle    */
 APIRET  rc            = NO_ERROR;            /* Return code               */

    rc = DosCreateEventSem(szSemName,      /* Name of semaphore to create  */
                           &hevEvent,      /* Handle of semaphore returned */
                           DC_SEM_SHARED,  /* Shared semaphore             */
                           FALSE);         /* Don't want it POSTed yet     */

    if (rc != NO_ERROR) {
        printf("DosCreateEventSem error: return code = %u\n", rc);
        return 1;       }

          /* OOPS... we changed our mind, POST the semaphore */

    rc = DosPostEventSem(hevEvent);

    if (rc != NO_ERROR) {
        printf("DosPostEventSem error: return code = %u\n", rc);
        return 1;
    }

return NO_ERROR;
}