WAIT(II) 8/5/73 WAIT(II)





WAIT(II)                     8/5/73                      WAIT(II)







NAME

     wait - wait for process to die



SYNOPSIS

     (wait = 7.)

     sys  wait



     wait(status)

     int *status;



DESCRIPTION

     Wait causes its caller to  delay  until  one  of  its  child

     processes  terminates.  If any child has died since the last

     wait, return is immediate; if there are no children,  return

     is  immediate  with the error bit set (resp. with a value of

     -1 returned).  In the case of several children several  wait

     calls are needed to learn of all the deaths.



     If no error is indicated on return, the r1 high byte  (resp.

     the  high byte stored into status ) contains the low byte of

     the child process r0 (resp. the argument of exit )  when  it

     terminated.   The  r1 (resp.  status ) low byte contains the

     termination status of the process.  See signal  (II)  for  a

     list  of  termination statuses (signals); 0 status indicates

     normal termination.  If the  0200  bit  of  the  termination

     status  is  set, a core image of the process was produced by

     the system.



     If the parent process  terminates  without  waiting  on  its

     children,  the  initialization  process  (process  ID  =  1)

     inherits the children.



SEE ALSO

     exit (II), fork (II), signal (II)



DIAGNOSTICS

     The error bit (c-bit) is set if there are  no  children  not

     previously  waited  for.   From  C,  a  returned value of -1

     indicates an error.
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