/* $Id: posix_spawn-execfd.c,v 1.6 2026/01/25 19:12:37 kostik Exp kostik $ */

#include <sys/types.h>
#include <sys/procdesc.h>
#include <sys/resource.h>
#include <sys/wait.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <signal.h>
#include <spawn.h>
#include <stdio.h>
#include <stdlib.h>

extern char **environ;

int
main(int argc, char *argv[])
{
	posix_spawnattr_t attr;
	struct __wrusage wru;
	siginfo_t si;
	int execfd, error, procfd, res, status;
	pid_t pid;

	argc--;
	argv++;

	if (argc == 0)
		exit(1);

	execfd = open(argv[0], O_EXEC);
	if (execfd == -1)
		err(1, "open %s", argv[0]);

	posix_spawnattr_init(&attr);
	posix_spawnattr_setexecfd_np(&attr, execfd);
	posix_spawnattr_setprocdescp_np(&attr, &procfd, 0);
	error = posix_spawn(&pid, NULL, NULL, &attr, argv, environ);
	if (error != 0)
		errc(1, error, "posix_spawn");

	for (;;) {
		res = pdwait(procfd, &status, WEXITED, &wru, &si);
		if (res == EINTR)
			continue;
		if (res == -1)
			err(1, "waitpid %d", pid);
		if (WIFEXITED(status)) {
			printf("Child %d exited, status %d\n",
			    pid, WEXITSTATUS(status));
		} else if (WIFSIGNALED(status)) {
			printf("Child %d terminated by signal %d\n",
			    pid, WTERMSIG(status));
		} else {
			printf("Child %d status %#x\n", pid, status);
		}
		break;
	}
}