/*-*- mode:c;indent-tabs-mode:nil;c-basic-offset:2;tab-width:8;coding:utf-8 -*-â
âvi: set net ft=c ts=2 sts=2 sw=2 fenc=utf-8                                :viâ
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â Copyright 2022 Justine Alexandra Roberts Tunney                              â
â                                                                              â
â Permission to use, copy, modify, and/or distribute this software for         â
â any purpose with or without fee is hereby granted, provided that the         â
â above copyright notice and this permission notice appear in all copies.      â
â                                                                              â
â THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL                â
â WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED                â
â WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE             â
â AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL         â
â DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR        â
â PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER               â
â TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR             â
â PERFORMANCE OF THIS SOFTWARE.                                                â
ââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââââ*/
#include "libc/calls/calls.h"
#include "libc/calls/syscall-sysv.internal.h"
#include "libc/calls/syscall_support-nt.internal.h"
#include "libc/dce.h"
#include "libc/intrin/strace.internal.h"
#include "libc/nt/console.h"
#include "libc/sysv/errfuns.h"

/**
 * Changes process group for process.
 * @vforksafe
 */
int setpgid(int pid, int pgid) {
  int rc, me;
  if (!IsWindows()) {
    rc = sys_setpgid(pid, pgid);
  } else {
    me = getpid();
    if ((!pid || pid == me) && (!pgid || pgid == me)) {
      /*
       * "When a process is created with CREATE_NEW_PROCESS_GROUP
       *  specified, an implicit call to SetConsoleCtrlHandler(NULL,TRUE)
       *  is made on behalf of the new process; this means that the new
       *  process has CTRL+C disabled. This lets shells handle CTRL+C
       *  themselves, and selectively pass that signal on to
       *  sub-processes. CTRL+BREAK is not disabled, and may be used to
       *  interrupt the process/process group."
       *                           ââQuoth MSDN Â§ CreateProcessW()
       */
      if (SetConsoleCtrlHandler(0, 1)) {
        rc = 0;
      } else {
        rc = __winerr();
      }
    } else {
      // irregular use cases not supported on windows
      rc = einval();
    }
  }
  STRACE("setpgid(%d, %d) â %d% m", pid, pgid, rc);
  return rc;
}
