wait(2)                                                             wait(2)


   NAME
         wait - wait for child process to stop or terminate

   SYNOPSIS
         #include <sys/types.h>
         #include <sys/wait.h>

         pidt wait(int *statloc);

   DESCRIPTION
         wait suspends the calling process until one of its immediate children
         terminates or until a child that is being traced stops because it has
         received a signal.  The wait system call will return prematurely if a
         signal is received.  If all child processes stopped or terminated
         prior to the call on wait, return is immediate.

         If wait returns because the status of a child process is available,
         it returns the process ID of the child process.  If the calling
         process had specified a non-zero value for stat_loc, the status of
         the child process will be stored in the location pointed to by
         stat_loc.  It may be evaluated with the macros described on wstat(5).
         In the following, status is the object pointed to by stat_loc:

               If the child process stopped, the high order 8 bits of status
               will contain the number of the signal that caused the process
               to stop and the low order 8 bits will be set equal to WSTOPFLG.

               If the child process terminated due to an exit call, the low
               order 8 bits of status will be 0 and the high order 8 bits will
               contain the low order 8 bits of the argument that the child
               process passed to exit; see exit(2).

               If the child process terminated due to a signal, the high order
               8 bits of status will be 0 and the low order 8 bits will
               contain the number of the signal that caused the termination.
               In addition, if WCOREFLG is set, a ``core image'' will have
               been produced; see signal(2).

         If wait returns because the status of a child process is available,
         then that status may be evaluated with the macros defined by
         wstat(5).

         If a parent process terminates without waiting for its child
         processes to terminate, the parent process ID of each child process
         is set to 1.  This means the initialization process inherits the
         child processes; see intro(2).

         wait will fail if one or both of the following is true:





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   wait(2)                                                             wait(2)


         ECHILD         The calling process has no existing unwaited-for child
                        processes.

         EINTR          The function was interrupted by a signal.

   SEE ALSO
         exec(2), exit(2), fork(2), intro(2), pause(2), ptrace(2), signal(2),
         signal(5), wstat(5).

   NOTES
         See NOTES in signal(2).

         If SIGCLD is held, then wait does not recognize death of children.

   DIAGNOSTICS
         If wait returns due to a stopped or terminated child process, the
         process ID of the child is returned to the calling process.
         Otherwise, a value of -1 is returned and errno is set to indicate the
         error.


































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