vectx_open
struct vectx* vectx_open(int, const char *, int, off_t, struct stat *, int *, const char *);
vp = vectx_open(fd, argv[optind], VE_GUESS,
ef->vctx = vectx_open(ef->fd, filename, VE_MUST,
ef.vctx = vectx_open(ef.fd, filename, VE_MUST,
vctx = vectx_open(fd, name, severity, 0L, NULL, &verror, __func__);
vctx = vectx_open(fd, argv[1], VE_MUST, 0L, NULL, &verror, __func__);