6 integer
f_back(a
) alist
*a
;
8 integer
f_back(alist
*a
)
15 f__curunit
= b
= &f__units
[a
->aunit
]; /* curunit for error messages */
17 f__fatal (131, "I/O recursion");
18 if(a
->aunit
>= MXUNIT
|| a
->aunit
< 0)
19 err(a
->aerr
,101,"backspace");
20 if(b
->useek
==0) err(a
->aerr
,106,"backspace");
22 fk_open(1, 1, a
->aunit
);
32 err(a
->aerr
,errno
,"backspace");
34 f
= b
->ufd
; /* may have changed in t_runc() */
47 { FSEEK(f
,-(off_t
)sizeof(uiolen
),SEEK_CUR
);
48 fread((char *)&n
,sizeof(uiolen
),1,f
);
49 FSEEK(f
,-(off_t
)n
-2*sizeof(uiolen
),SEEK_CUR
);
58 for(y
= x
; y
< w
; y
++) {
69 err(a
->aerr
,(EOF
),"backspace");
72 FSEEK(f
, z
, SEEK_SET
);