pid_t
spawn (const char *path, char *const *argv,
int in, int out, int err, cbv::ptr postforkcb, char *const *env)
{
int fds[2];
if (pipe (fds) < 0)
return -1;
close_on_exec (fds[0]);
close_on_exec (fds[1]);
pid_t pid = afork ();
if (pid < 0)
return pid;
if (!pid) {
amain_panic = true;
close (fds[0]);
setstdfds (in, out, err);
if (postforkcb)
(*postforkcb) ();
if (env)
execve (path, argv, env);
else
execv (path, argv);
int saved_err = errno;
v_write (fds[1], &saved_err, sizeof (saved_err));
close (fds[1]);
// Since we return a useful errno, there is no need to print
// anything in the child process. Just exit.
_exit (1);
}
close (fds[1]);
int chld_err;
int n = read (fds[0], &chld_err, sizeof (chld_err));
close (fds[0]);
if (n == 0)
return pid;
errno = chld_err;
return -1;
}
static int setup(int argc, char** argv)
{
setargs(argc, argv);
if(setstdfds())
retwarn(-1, "cannot set initial fds 0, 1, 2");
if(setinitctl())
/* Not having telinit is bad, but aborting system startup
for this mere reason is likely even worse. */
warn("can't initialize initctl, init will be uncontrollable");
if(setsignals())
retwarn(-1, "failed to set signal handlers");
if(!configure(NONSTRICT))
setnewconf();
else if(!cfg)
retwarn(-1, "initial configuration error");
return 0;
}
pid_t
aspawn (const char *path, char *const *argv,
int in, int out, int err, cbv::ptr postforkcb, char *const *env)
{
pid_t pid = afork ();
if (pid < 0)
return pid;
if (pid)
return pid;
setstdfds (in, out, err);
if (postforkcb)
(*postforkcb) ();
if (env)
execve (path, argv, env);
else
execv (path, argv);
warn ("%s: %m\n", path);
_exit (1);
}