V10/lsys/sys/pioctl.h
#define PIOC ('p'<<8)
#define PIOCGETPR (PIOC|1) /* read struct proc */
#define PIOCOPENT (PIOC|2) /* open text file for reading */
#define PIOCEXCLU (PIOC|3) /* mark text for exclusive use */
#define PIOCSTOP (PIOC|4) /* send STOP signal and... */
#define PIOCWSTOP (PIOC|5) /* wait for process to STOP */
#define PIOCRUN (PIOC|6) /* make process runnable */
#define PIOCSMASK (PIOC|7) /* set signal trace bit mask */
#define PIOCCSIG (PIOC|8) /* clear current signal */
#define PIOCKILL (PIOC|9) /* send signal */
#define PIOCSEXEC (PIOC|10) /* stop on exec */
#define PIOCREXEC (PIOC|11) /* run on exec */
#define PIOCNICE (PIOC|12) /* set nice priority */
#define PIOCSSIG (PIOC|13) /* set current signal */