[f40a309] | 1 | /*
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| 2 | ============================================================================
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| 3 | write.c -- write() and friends
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| 4 | Version 17 -- 1987-10-27 -- D.N. Lynx Crowe
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| 5 | ============================================================================
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| 6 | */
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| 7 |
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| 8 | #define DEBUGIT 0
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| 9 |
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| 10 | #include "biosdefs.h"
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| 11 | #include "io.h"
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| 12 | #include "errno.h"
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| 13 | #include "stddefs.h"
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| 14 |
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[0580615] | 15 | int _filewr(struct fcb *fp, char *buffer, unsigned len);
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[f40a309] | 16 |
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[0580615] | 17 | extern int _badfd(void);
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| 18 | extern int _conwr(int kind, char *buff, int len);
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| 19 | extern int blkwr(struct fcb *fcp, char *buf, int ns);
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| 20 | extern int ReadRN(struct fcb *fcp, char *buf);
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| 21 | extern int WriteRN(struct fcb *fcp, char *buf);
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| 22 | extern int _newcls(void);
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| 23 | extern short micons(short wi);
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| 24 | extern void _ptcl12(unsigned *fat, unsigned cl, unsigned val);
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[f40a309] | 25 |
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[0580615] | 26 | extern long miconl(long wi);
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[f40a309] | 27 |
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[0580615] | 28 | extern char *memset(char *sp, char c, int n);
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[f40a309] | 29 |
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[0c834c5] | 30 | extern int _fatmod;
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[f40a309] | 31 |
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| 32 | extern unsigned _thefat[];
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| 33 |
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| 34 | extern struct bpb *_thebpb;
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| 35 |
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| 36 | #if DEBUGIT
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| 37 | extern short fsdebug;
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| 38 | #endif
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| 39 |
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| 40 | static int (*wr_tab[])() = { /* write routine dispatch table */
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| 41 |
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| 42 | _badfd, /* 0 - invalid entry */
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| 43 | _filewr, /* 1 - disk file */
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| 44 | _conwr /* 2 - console device */
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| 45 | };
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| 46 |
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| 47 | /* |
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| 48 |
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| 49 | */
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| 50 |
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| 51 | /*
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| 52 | ============================================================================
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| 53 | _putsec(fp, buf, len) -- write 'len' bytes from 'buf' on file 'fp'
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| 54 | ============================================================================
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| 55 | */
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[0580615] | 56 |
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[f40a309] | 57 | int _putsec(struct fcb *fp, char *buf, unsigned len)
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| 58 | {
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| 59 | #if DEBUGIT
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| 60 | if (fsdebug)
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| 61 | printf("_putsec($%08lX, $%08lx, %d): initial curlsn=%ld\n",
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| 62 | fp, buf, len, fp->curlsn);
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| 63 | #endif
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| 64 |
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| 65 | if ((errno = ReadRN(fp, Wrkbuf)) EQ 1) { /* try to read sector */
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| 66 |
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| 67 | #if DEBUGIT
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| 68 | if (fsdebug)
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| 69 | printf("_putsec(): ReadRN saw EOF at curlsn=%ld, asects=%ld\n",
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| 70 | fp->curlsn, fp->asects);
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| 71 | #endif
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| 72 |
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| 73 | errno = 0; /* we're at EOF */
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| 74 | memset(Wrkbuf, 0x1A, BPSEC); /* pad end of sector */
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| 75 |
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| 76 | } else if (errno)
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| 77 | return(FAILURE);
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| 78 |
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| 79 | memcpy(Wrkbuf + fp->offset, buf, len); /* move in the new data */
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| 80 |
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| 81 | if ((errno = WriteRN(fp, Wrkbuf)) NE 0) { /* write the sector */
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| 82 |
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| 83 | #if DEBUGIT
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| 84 | if (fsdebug)
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| 85 | printf("_putsec(): WriteRN() FAILED (%d) - curlsn=%ld\n",
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| 86 | errno, fp->curlsn);
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| 87 | #endif
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| 88 |
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| 89 | return(FAILURE);
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| 90 | }
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| 91 |
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| 92 | if ((fp->offset = (fp->offset + len) & (BPSEC - 1)) EQ 0) {
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| 93 |
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| 94 | ++fp->curlsn; /* update file position */
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| 95 |
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| 96 | if (_seek(fp) < 0) {
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| 97 |
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| 98 | #if DEBUGIT
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| 99 | if (fsdebug)
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| 100 | printf("_putsec(): _seek() failed - curlsn=%ld, asects=%ld\n",
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| 101 | fp->curlsn, fp->asects);
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| 102 | #endif
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| 103 |
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| 104 | return(FAILURE);
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| 105 | }
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| 106 | }
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| 107 |
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| 108 | #if DEBUGIT
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| 109 | if (fsdebug)
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| 110 | printf("_putsec(): final curlsn=%ld, offset=%d, len=%d\n",
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| 111 | fp->curlsn, fp->offset, len);
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| 112 | #endif
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| 113 |
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| 114 | return(SUCCESS);
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| 115 | }
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| 116 |
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| 117 | /* |
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| 118 |
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| 119 | */
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| 120 |
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| 121 | /*
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| 122 | ============================================================================
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| 123 | _filewr(fp, buffer, len) -- write 'len' bytes on file 'fp'
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| 124 | from 'buffer'.
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| 125 | ============================================================================
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[0580615] | 126 | */
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[f40a309] | 127 |
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| 128 | int _filewr(struct fcb *fp, char *buffer, unsigned len)
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| 129 | {
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| 130 | register unsigned j, k, l;
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| 131 | int clustr;
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| 132 | register long curpos;
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| 133 |
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| 134 | curpos = fp->offset + (fp->curlsn << FILESHFT); /* get position */
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| 135 |
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| 136 | if (fp->de.bclust EQ 0) { /* see if we need to allocate */
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| 137 |
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| 138 | #if DEBUGIT
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| 139 | if (fsdebug)
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| 140 | if (curpos)
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| 141 | printf("_filewr(): ERROR - bclust EQ 0 and curpos (%ld) NE 0\n",
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| 142 | curpos);
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| 143 | #endif
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| 144 |
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| 145 | if (0 EQ (clustr = _newcls())) { /* allocate a cluster */
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| 146 |
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| 147 | errno = EIO;
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| 148 | return(len);
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| 149 | }
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| 150 |
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| 151 | fp->de.bclust = micons(clustr); /* update FCB */
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| 152 | _ptcl12(_thefat, clustr, 0x0FF8); /* update FAT */
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| 153 | _fatmod = TRUE;
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| 154 | fp->curdsn = _cl2lsn(_thebpb, clustr); /* set curdsn */
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| 155 | fp->curcls = clustr;
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| 156 | fp->clsec = 0;
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| 157 | fp->asects = _thebpb->clsiz;
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| 158 | #if DEBUGIT
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| 159 | if (fsdebug) {
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| 160 |
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| 161 | printf("_filewr(): allocated initial cluster=%d, asects=%ld\n",
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| 162 | clustr, fp->asects);
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| 163 | SnapFCB(fp);
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| 164 | }
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| 165 | #endif
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| 166 | }
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| 167 |
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| 168 | l = 0; /* zero the length-written counter */
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| 169 |
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| 170 | #if DEBUGIT
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| 171 | if (fsdebug)
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| 172 | printf("_filewr(): init pos=%ld, len=%u, curcls=%u, offset=%u\n",
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| 173 | curpos, len, fp->curcls, fp->offset);
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| 174 | #endif
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| 175 |
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| 176 | if (fp->offset) { /* see if we have a partial sector to fill */
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| 177 |
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| 178 | if ((l = (BPSEC - fp->offset)) > len)
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| 179 | l = len;
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| 180 |
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| 181 | if (_putsec(fp, buffer, l)) /* fill up the sector */
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| 182 | return(-1);
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| 183 | }
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| 184 |
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| 185 | if (k = (len - l) / BPSEC) { /* write out any full sectors */
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| 186 |
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| 187 | if ((j = blkwr(fp, buffer + l, k)) NE 0) {
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| 188 |
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| 189 | l += (k - j) * BPSEC; /* update amount written */
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| 190 |
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| 191 | if ((curpos + l) > fp->curlen) /* udpate file length */
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| 192 | fp->de.flen = miconl(fp->curlen = curpos + l);
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| 193 |
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| 194 | #if DEBUGIT
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| 195 | if (fsdebug)
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| 196 | printf("_filewr(): ERROR - curlen=%ld, curlsn=%ld, curdsn=%ld\n",
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| 197 | fp->curlen, fp->curlsn, fp->curdsn);
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| 198 | #endif
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| 199 |
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| 200 | return(l);
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| 201 | }
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| 202 |
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| 203 | l += k * BPSEC; /* update amount written */
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| 204 | }
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| 205 | /* |
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| 206 |
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| 207 | */
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| 208 | if (l < len) { /* write out partial sector at end */
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| 209 |
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| 210 | if (_putsec(fp, buffer + l, len - l)) {
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| 211 |
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| 212 | if ((curpos + l) > fp->curlen) /* update file length */
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| 213 | fp->de.flen = miconl(fp->curlen = curpos + l);
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| 214 |
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| 215 | #if DEBUGIT
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| 216 | if (fsdebug)
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| 217 | printf("_filewr(): ERROR - curlen=%ld, curlsn=%ld, curdsn=%ld\n",
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| 218 | fp->curlen, fp->curlsn, fp->curdsn);
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| 219 | #endif
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| 220 |
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| 221 | return(l);
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| 222 | }
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| 223 | }
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| 224 |
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| 225 | if ((curpos + len) > fp->curlen) /* update file length */
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| 226 | fp->de.flen = miconl(fp->curlen = curpos + len);
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| 227 |
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| 228 | #if DEBUGIT
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| 229 | if (fsdebug)
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| 230 | printf("_filewr(): final curlen=%ld, flen=$%08lX, curlsn=%ld, curdsn=%ld\n",
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| 231 | fp->curlen, fp->de.flen, fp->curlsn, fp->curdsn);
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| 232 | #endif
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| 233 |
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| 234 | return(len);
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| 235 | }
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| 236 |
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| 237 | /* |
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| 238 |
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| 239 | */
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| 240 |
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| 241 | /*
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| 242 | ============================================================================
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[0580615] | 243 | write(fd, buff, len) -- write 'len' bytes from 'buff' on file 'fd'
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[f40a309] | 244 | ============================================================================
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| 245 | */
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| 246 |
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| 247 | int write(int fd, char *buff, unsigned len)
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| 248 | {
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| 249 | register struct channel *chp;
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| 250 |
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| 251 | if ((fd < 0) OR (fd > MAXCHAN)) {
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| 252 |
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| 253 | errno = EBADF;
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| 254 | return(-1);
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| 255 | }
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| 256 |
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| 257 | chp = &chantab[fd];
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| 258 |
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| 259 | return((*wr_tab[chp->c_write])(chp->c_arg, buff, len));
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| 260 | }
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