Kill send an interrupt to a task #include <signal.h> kill int tid int interrupt Kill sends the interrupt type "interrupt" to the task with id "tid". Both tasks, sender and receiver, must have the same user id unless the user is the super user. The include file contains definitions of the defined signals as follows: /* OS-9 signals */ #define SIGKILL 0 /* system abort (cannot be caught or ignored)*/ #define SIGWAKE 1 /* wake up */ #define SIGQUIT 2 /* keyboard abort */ #define SIGINT 3 /* keyboard interrupt */ Other user-defined signals may, of course, be sent. Kill returns 0 from a successful call and -1 if the task does not exist, the effective user ids do not match, or the user is not the system manager. signal(), OS-9 shell command "kill"