13 f__curunit = b = &f__units[a->aunit]; /* curunit for error messages */
15 f__fatal (131, "I/O recursion");
16 if (a->aunit >= MXUNIT || a->aunit < 0)
17 err (a->aerr, 101, "backspace");
19 err (a->aerr, 106, "backspace");
22 fk_open (1, 1, a->aunit);
33 if (f__nowreading (b))
34 err (a->aerr, errno, "backspace");
36 f = b->ufd; /* may have changed in t_runc() */
45 FSEEK (f, x, SEEK_SET);
51 FSEEK (f, -(off_t) sizeof (uiolen), SEEK_CUR);
52 fread ((char *) &n, sizeof (uiolen), 1, f);
53 FSEEK (f, -(off_t) n - 2 * sizeof (uiolen), SEEK_CUR);
62 FSEEK (f, x, SEEK_SET);
63 for (y = x; y < w; y++)
76 err (a->aerr, (EOF), "backspace");
79 FSEEK (f, z, SEEK_SET);