[f40a309] | 1 | /*
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| 2 | =============================================================================
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| 3 | ftell.c -- return current file position
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| 4 | Version 7 -- 1987-10-28 -- 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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[b28a12e] | 10 | #include "ram.h"
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[f40a309] | 11 |
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| 12 | /*
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| 13 | =============================================================================
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| 14 | ftell(fp) -- return the current position of file 'fp'.
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| 15 | =============================================================================
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| 16 | */
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| 17 |
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[7258c6a] | 18 | int32_t ftell(FILE *fp)
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[f40a309] | 19 | {
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| 20 | register struct fcb *fcp;
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| 21 | register struct channel *chp;
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[7258c6a] | 22 | register int32_t dpos, pos, diff;
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[f40a309] | 23 |
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| 24 | if (fp EQ (FILE *)0L) { /* see if we point at a FILE */
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| 25 |
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| 26 | #if DEBUGIT
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| 27 | if (fsdebug)
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| 28 | printf("ftell($%08.8lX): ERROR - null FILE pointer\n", fp);
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| 29 | #endif
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| 30 |
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| 31 | return(0L);
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| 32 | }
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| 33 |
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| 34 | if (!fp->_flags & _BUSY) { /* see if it's open */
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| 35 |
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| 36 | #if DEBUGIT
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| 37 | if (fsdebug)
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| 38 | printf("ftell($%08.8lX): ERROR - FILE not open\n", fp);
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| 39 | #endif
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| 40 |
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| 41 | return(0L);
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| 42 | }
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| 43 |
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| 44 | chp = &chantab[fp->_unit]; /* point at the channel */
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| 45 |
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| 46 | if (chp->c_close NE _filecl) { /* see if it's seekable */
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| 47 |
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| 48 | #if DEBUGIT
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| 49 | if (fsdebug)
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| 50 | printf("ftell($%08.8lX): ERROR - FILE device not seekable\n",
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| 51 | fp);
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| 52 | #endif
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| 53 |
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| 54 | return(0L);
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| 55 | }
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| 56 |
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| 57 | fcp = chp->c_arg; /* point at the FCB */
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| 58 |
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| 59 | dpos = fcp->offset + (fcp->curlsn << FILESHFT);
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| 60 |
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| 61 | if (fp->_flags & _DIRTY) /* adjust for the buffering */
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[7258c6a] | 62 | pos = dpos + (diff = ((int32_t)fp->_bp - (int32_t)fp->_buff));
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[f40a309] | 63 | else if (fp->_bp)
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[7258c6a] | 64 | pos = dpos - (diff = ((int32_t)fp->_bend - (int32_t)fp->_bp));
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[f40a309] | 65 | else
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| 66 | pos = dpos;
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| 67 |
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| 68 | #if DEBUGIT
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| 69 | if (fsdebug) {
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| 70 |
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| 71 | printf("ftell($%08.8lX): flags=$%04.4X, buff=$%08.8lX, bp=$%08.8lX, bend=$%08.8lX\n",
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| 72 | fp, fp->_flags, fp->_buff, fp->_bp, fp->_bend);
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| 73 | printf("ftell($%08.8lX): fcp=$%08.8lX, pos=%ld, dpos=%ld, diff=%ld\n",
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| 74 | fp, fcp, pos, dpos, diff);
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| 75 | printf("ftell($%08.8lX): curlsn=%ld, offset=%u\n",
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| 76 | fp, fcp->curlsn, fcp->offset);
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| 77 |
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| 78 | if ((fp->_flags & _DIRTY) AND (fp->_bp EQ NULL))
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| 79 | printf("ftell($%08.8lX): ERROR - file is DIRTY and bp is NULL\n",
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| 80 | fp);
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| 81 | }
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| 82 | #endif
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| 83 |
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| 84 | return(pos);
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| 85 | }
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[6262b5c] | 86 |
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