FORK(2)                 GENIX Programmer's Manual                 FORK(2)



      NAME
           fork - spawn new process

      SYNOPSIS
           fork()

      DESCRIPTION
           Fork and vfork(2) are the only ways new processes are created.  With
           fork  , the new process's core image is a copy of that of the caller
           of fork.  The only distinction is the fact that the  value  returned
           in  the  old  (parent)  process  contains  the process ID of the new
           (child) process, while the value returned in the child is  0.   Pro-
           cess  ID's  range  from  1  to  30,000.   This process ID is used by
           wait(2).

           Files open before the fork are shared, and have a common  read-write
           pointer.   In  particular,  this  is the way that standard input and
           output files are passed and also how pipes are set up.

           Vfork is the most efficient way of creating a new process  when  the
           fork  is to be followed shortly by an exec, but is not suitable when
           the fork is not to be followed by an exec.

      SEE ALSO
           wait(2), exec(2), vfork(2)

      DIAGNOSTICS
           Returns -1 and fails to create a process  if:  there  is  inadequate
           swap  space,  the user is not super-user and has too many processes,
           or the system's process table is full.  Only the super-user can take
           the last process-table slot.
























      Printed 11/16/83                                                        1