source: buchla-68k/orig/IOLIB/WRITERN.C@ f806726

Last change on this file since f806726 was 3ae31e9, checked in by Thomas Lopatic <thomas@…>, 7 years ago

Imported original source code.
  • Property mode set to 100755
File size: 2.3 KB
Line 
1/*
2 =============================================================================
3 writern.c -- write a random sector onto a file
4 Version 6 -- 1987-12-15 -- D.N. Lynx Crowe
5
6 int
7 WriteRN(fcp, buf)
8 struct fcb *fcp;
9 char *buf;
10
11 Writes a sector onto file 'fcp' from 'buf'. Seeks as needed.
12 Returns SUCCESS (0) if OK, FAILURE (-1) for errors.
13 =============================================================================
14*/
15
16#define DEBUGIT 0
17
18#include "stddefs.h"
19#include "biosdefs.h"
20#include "errno.h"
21#include "errdefs.h"
22#include "fspars.h"
23
24extern long _berrno;
25extern int _seek();
26
27#if DEBUGIT
28extern short fsdebug;
29#endif
30
31#if TBUFFER
32extern long _secwr(); /* update buffer function */
33#endif
34
35/*
36
37*/
38
39/*
40 =============================================================================
41 WriteRN(fcp, buf) -- Writes a sector onto file 'fcp' from 'buf'.
42 Seeks as needed. Returns SUCCESS (0) if OK, FAILURE (-1) for errors.
43 =============================================================================
44*/
45
46int
47WriteRN(fcp, buf)
48struct fcb *fcp;
49char *buf;
50{
51 int sv; /* seek return code */
52 long brc; /* bios return code */
53
54 if (sv = _seek(fcp)) { /* try to find the sector we want */
55
56 if (sv < 0) { /* seek error ? */
57
58#if DEBUGIT
59 if (fsdebug)
60 printf("WriteRN(): _seek FAILED (%d) - curlsn=%ld, curdsn=%ld\n",
61 sv, fcp->curlsn, fcp->curdsn);
62#endif
63
64 errno = EIO; /* I/O error or seek past EOF */
65 return(FAILURE);
66
67 } else if (sv EQ 2) { /* at hard EOF ? */
68
69 if (_alcnew(fcp)) { /* allocate a new cluster */
70
71 errno = EIO;
72 return(FAILURE);
73 }
74#if DEBUGIT
75 if (fsdebug)
76 printf("WriteRN(): cluster allocated - curcls=%d, clsec=%d\n",
77 fcp->curcls, fcp->clsec);
78#endif
79
80 }
81 }
82
83#if DEBUGIT
84 if (fsdebug)
85 printf("WriteRN(): curlsn=%ld, curdsn=%ld\n",
86 fcp->curlsn, fcp->curdsn);
87#endif
88
89 /* write the sector */
90
91 if (brc = BIOS(B_RDWR, 1, buf, 1, (short)fcp->curdsn, 0)) {
92
93#if DEBUGIT
94 if (fsdebug)
95 printf("WriteRN(): B_RDWR FAILED - brc=%ld\n", brc);
96#endif
97
98 _berrno = brc; /* log the error */
99 errno = EIO; /* ... as an I/O error */
100 return(FAILURE); /* return: ERROR */
101 }
102
103#if TBUFFER
104 _secwr(buf, (short)fcp->curdsn);
105#endif
106
107 return(SUCCESS); /* return: SUCCESS */
108}
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