ref: 1f7ebe9e5cf509d5720bb103accddb2e36c039f6
dir: /sys/src/cmd/auth/newns.c/
#include <u.h>
#include <libc.h>
#include <auth.h>
extern int newnsdebug;
char	*defargv[] = { "/bin/rc", "-i", nil };
char	*namespace = "/lib/namespace";
int	add = 0;
void
usage(void)
{
	fprint(2, "usage: %s [-ad] [-n namespace] [cmd [args...]]\n", argv0);
	exits("usage");
}
void
run(char **a)
{
	exec(a[0], a);
	if(a[0][0] != '/' && a[0][0] != '#' &&
	  (a[0][0] != '.' || (a[0][1] != '/' &&
		             (a[0][1] != '.' ||  a[0][2] != '/'))))
		exec(smprint("/bin/%s", a[0]), a);
	sysfatal("exec: %s: %r", a[0]);
}
void
main(int argc, char **argv)
{
	ARGBEGIN{
	case 'a':
		add = 1;
		break;
	case 'd':
		newnsdebug = 1;
		break;
	case 'n':
		namespace = EARGF(usage());
		break;
	default:
		usage();
		break;
	}ARGEND
	if(add){
		rfork(RFNAMEG);
		addns(getuser(), namespace);
	}else
		newns(getuser(), namespace);
	if(argc == 0)
		argv = defargv;
	run(argv);
}