[f40a309] | 1 | /*
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| 2 | =============================================================================
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| 3 | fopen.c -- open a stream file for the Buchla 700 C I/O Library
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| 4 | Version 4 -- 1987-06-30 -- D.N. Lynx Crowe
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| 5 | =============================================================================
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| 6 | */
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| 7 |
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| 8 | #include "stdio.h"
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| 9 | #include "fcntl.h"
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| 10 | #include "errno.h"
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| 11 | #include "stddefs.h"
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| 12 |
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| 13 | extern long lseek();
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| 14 |
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| 15 | FILE *
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| 16 | _opener(name, mode, aflag)
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| 17 | char *name, *mode;
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| 18 | int aflag;
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| 19 | {
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| 20 | register FILE *fp;
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| 21 | register int plusopt;
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| 22 |
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| 23 | fp = Cbuffs;
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| 24 |
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| 25 | while ( fp->_flags ) {
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| 26 |
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| 27 | if ( ++fp GE (Cbuffs + NSTREAMS))
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| 28 | return(NULL);
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| 29 | }
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| 30 |
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| 31 | plusopt = mode[1] EQ '+';
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| 32 |
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| 33 | switch (0x007F & *mode) {
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| 34 |
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| 35 | case 'r': /* read mode */
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| 36 | if ((fp->_unit = open(name, (plusopt ? O_RDWR : O_RDONLY)|aflag)) EQ -1)
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| 37 | return(NULL);
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| 38 | break;
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| 39 |
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| 40 | case 'w': /* write mode */
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| 41 | if ((fp->_unit = open(name, (plusopt ? O_RDWR : O_WRONLY)|aflag|O_CREAT|O_TRUNC)) EQ -1)
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| 42 | return(NULL);
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| 43 |
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| 44 | break;
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| 45 |
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| 46 | case 'a': /* append mode */
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| 47 | if ((fp->_unit = open(name, (plusopt ? O_RDWR : O_WRONLY)|aflag|O_CREAT)) EQ -1)
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| 48 | return(NULL);
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| 49 |
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| 50 | if (lseek(fp->_unit, 0L, 2) < 0) {
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| 51 |
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| 52 | close(fp->_unit);
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| 53 | return(NULL); /* couldn't append */
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| 54 | }
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| 55 |
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| 56 | break;
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| 57 |
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| 58 | default:
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| 59 | errno = EINVAL;
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| 60 | return(NULL);
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| 61 | }
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| 62 |
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| 63 | fp->_flags = _BUSY;
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| 64 | fp->_buflen = BUFSIZ;
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| 65 | fp->_buff = 0;
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| 66 | fp->_bend = 0; /* nothing in buffer */
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| 67 | fp->_bp = 0;
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| 68 | return(fp);
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| 69 | }
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| 70 |
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| 71 | /* |
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| 72 |
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| 73 | */
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| 74 |
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| 75 | FILE *
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| 76 | fopen(name, mode)
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| 77 | char *name, *mode;
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| 78 | {
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| 79 | return(_opener(name, mode, 0));
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| 80 | }
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| 81 |
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| 82 | FILE *
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| 83 | fopena(name, mode)
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| 84 | char *name, *mode;
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| 85 | {
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| 86 | return(_opener(name, mode, 0));
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| 87 | }
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| 88 |
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| 89 | FILE *
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| 90 | fopenb(name, mode)
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| 91 | char *name, *mode;
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| 92 | {
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| 93 | return(_opener(name, mode, O_RAW));
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| 94 | }
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