fork 래핑했는데,

ㅋㅋㅋ

rust에 nix 크레이트인가? 암튼 그런거 있다는데, 그거 따라했어

ㅋㅋㅋ

Ada(에이다)로도 러스트 Result 이런거 된다.

무슨 러스트만의 전유물인줄 아는 빠돌이들 많은거 같은데,

Ada 언어하면 눈 뒤집어진다. 없는게 없다. 다 있다. ㅎㅎ

그래서 어떻게 됐느냐?

fork 하면, 각각의 경우에 따라 두가지 결과를 리턴한다. ㅎㅎ

(status => Parent, child_pid => pid)

(status => Child)

이렇게 희안하게 리턴하는게 Ada로 가능함.

ㅋㅋ

-- -*- Mode: Ada; indent-tabs-mode: nil; c-basic-offset: 2; tab-width: 2 -*-

-- cada-process.adb

-- Copyright (c) 2025 Hodong Kim <hodong@nimfsoft.art>

--

-- Permission to use, copy, modify, and/or distribute this software for any

-- purpose with or without fee is hereby granted.

--

-- THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES

-- WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF

-- MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR

-- ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES

-- WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN

-- ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF

-- OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.

with Interfaces.C;

with unistd_h;

with stdlib_h;

with Cada;

with Cada.Error;

package body Cada.Process is

  use type Interfaces.C.int;

  procedure exit_process (status : Integer := EXIT_SUCCESS) is

  begin

    stdlib_h.c_exit (Interfaces.C.int (status));

    raise Program_Error with "Unreachable code: c_exit() should not return.";

  end exit_process;

  function get_pid return Pid is

  begin

    return unistd_h.getpid;

  end get_pid;

  function set_sid return Pid is

    result : constant Pid := unistd_h.setsid;

  begin

    if result = -1 then

      Cada.raise_from_errno (Cada.Error.get_errno, "setsid failed");

    end if;

    return result;

  end set_sid;

  function fork return Fork_Result is

    result : constant Pid := unistd_h.fork;

  begin

    case result is

      when 0 =>

        -- child프로세스입니다: status가 Child인 레코드 반환

        return (status => Child);

      when -1 =>

        -- 오류 발생 시 예외 처리

        Cada.raise_from_errno (Cada.Error.get_errno, "fork failed");

      when others =>

           -- parent프로세스입니다, child_pid)'에 해당:

           -- status가 Parent이고 자식 Pid를 포함한 레코드 반환

        return (status => Parent, child_pid => result);

    end case;

  end fork;

end Cada.Process;