start_command
int start_command(char *, sigset_t *, int, int, char *, char *, char *);
pid = start_command(sh, 0, -1, pivec[1], "-c", cmdbuf, NULL);
pid = start_command(sh, &nset, image, -1, "-c", fname,
if ((pid = start_command(cmd, &nset, fd0, fd1, NULL, NULL, NULL)) < 0) {
if ((pid = start_command(cmd, mask, infd, outfd, a0, a1, a2)) < 0)