---------------------------------------------------------------------------

UNSAFE MODULE SystemPosix EXPORTS System;

IMPORT Text, Ctypes, (*Uexec,*) Process, Fmt, Uerror;
IMPORT (*SchedulerPosix*) Word;

PROCEDURE Hostname() : TEXT =
  VAR
    buf : ARRAY [0..1024] OF CHAR;
    len := 1024;
  BEGIN
    IF gethostname(ADR(buf), len) = 0 THEN
      buf[1024] := '\000';
      len := 0;
      WHILE len < 1024 AND buf[len] # '\000' DO
        INC(len);
      END;
      RETURN Text.FromChars(SUBARRAY(buf, 0, len));
    END;
    RETURN "amnesiac";
  END Hostname;

PROCEDURE Wait(p: Process.T): Process.ExitCode RAISES {Error} =
  VAR
    result, status: Ctypes.int;
    pid := Process.GetID(p);
    e : Ctypes.int;
    err : TEXT;
  BEGIN

Use this once m3core is new enough. result := SchedulerPosix.WaitProcess (pid, status);

    (* 0 should be WNOHANG on user threads platforms, which there are presently none of *)
    result := (*Uexec.*)waitpid (pid, ADR(status), 0);
    IF result < 0 THEN
      e := GetErrno();
      IF (e = Uerror.ECHILD) THEN err := "The process specified in pid does not exist or is not a child of the calling process.";
      ELSIF (e = Uerror.EINTR) THEN err := "WNOHANG was not set and an unblocked signal or a SIGCHLD was caught.";
      ELSIF (e = Uerror.EINVAL) THEN err := "The options argument was invalid.";
      ELSE
        err := "Unexpected return value " & Fmt.Int(e);
      END;
      RAISE Error("Could not wait: " & err);
    END;

Use this once m3core is new enough. Uexec.RepackStatus(status);

    (* ensure non-zero implies lower bits non-zero *)
    IF (status # 0) AND (Word.And(status, 16_FF) = 0) THEN
      status := 1;
    END;
    RETURN MIN(LAST(Process.ExitCode), status);
  END Wait;

BEGIN
END SystemPosix.