[8] | 1 | /* |
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| 2 | * $Source: /afs/dev.mit.edu/source/repository/athena/bin/tarmail/atob.c,v $ |
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| 3 | * $Author: jtkohl $ |
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| 4 | * $Locker: $ |
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| 5 | * $Header: /afs/dev.mit.edu/source/repository/athena/bin/tarmail/atob.c,v 1.1 1985-04-25 20:34:23 jtkohl Exp $ |
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| 6 | */ |
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| 7 | |
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| 8 | #ifndef lint |
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| 9 | static char *rcsid_atob_c = "$Header: /afs/dev.mit.edu/source/repository/athena/bin/tarmail/atob.c,v 1.1 1985-04-25 20:34:23 jtkohl Exp $"; |
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| 10 | #endif lint |
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| 11 | |
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| 12 | /*stream filter to change printable ascii from "btoa" back into 8 bit bytes*/ |
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| 13 | /*if bad chars, or Csums do not match: exit(1) [and NO output]*/ |
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| 14 | /*assumes that int is 32 bits*/ |
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| 15 | |
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| 16 | #include <stdio.h> |
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| 17 | |
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| 18 | #define reg register |
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| 19 | |
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| 20 | #define streq(s0, s1) strcmp(s0, s1) == 0 |
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| 21 | |
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| 22 | int Ceor = 0; |
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| 23 | int Csum = 0; |
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| 24 | int Crot = 0; |
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| 25 | int bcount = 0; |
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| 26 | int word = 0; |
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| 27 | |
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| 28 | fatal() { |
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| 29 | fprintf(stderr, "bad format or Csum to atob\n"); |
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| 30 | exit(1); |
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| 31 | } |
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| 32 | |
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| 33 | #define DE(c) ((c) - ' ') |
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| 34 | |
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| 35 | decode(c) reg c; |
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| 36 | { |
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| 37 | if (c == 'z') { |
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| 38 | if (bcount != 0) { |
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| 39 | fatal(); |
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| 40 | } |
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| 41 | else{ |
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| 42 | byteout(0); |
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| 43 | byteout(0); |
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| 44 | byteout(0); |
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| 45 | byteout(0); |
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| 46 | } |
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| 47 | } |
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| 48 | else if ((c >= ' ') && (c < (' ' + 85))) { |
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| 49 | if (bcount == 0) { |
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| 50 | word = DE(c); |
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| 51 | ++bcount; |
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| 52 | } |
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| 53 | else if (bcount < 4) { |
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| 54 | word *= 85; |
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| 55 | word += DE(c); |
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| 56 | ++bcount; |
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| 57 | } |
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| 58 | else{ |
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| 59 | word = ((unsigned) word * (unsigned) 85) + DE(c); |
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| 60 | byteout((word >> 24) & 255); |
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| 61 | byteout((word >> 16) & 255); |
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| 62 | byteout((word >> 8) & 255); |
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| 63 | byteout(word & 255); |
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| 64 | word = 0; |
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| 65 | bcount = 0; |
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| 66 | } |
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| 67 | } |
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| 68 | else{ |
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| 69 | fatal(); |
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| 70 | } |
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| 71 | } |
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| 72 | |
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| 73 | FILE *tmpfile; |
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| 74 | |
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| 75 | byteout(c) reg c; |
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| 76 | { |
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| 77 | Ceor ^= c; |
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| 78 | Csum += c; |
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| 79 | Csum += 1; |
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| 80 | if ((Crot & 0x80000000)) { |
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| 81 | Crot <<= 1; |
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| 82 | Crot += 1; |
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| 83 | } |
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| 84 | else{ |
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| 85 | Crot <<= 1; |
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| 86 | } |
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| 87 | Crot += c; |
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| 88 | putc(c, tmpfile); |
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| 89 | } |
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| 90 | |
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| 91 | main(argc, argv) char **argv; |
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| 92 | { |
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| 93 | reg c, i; |
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| 94 | char tmpname[100]; |
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| 95 | char buf[100]; |
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| 96 | int n1, n2, oeor, osum, orot; |
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| 97 | if (argc != 1) { |
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| 98 | fprintf(stderr,"bad args to %s\n", argv[0]); |
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| 99 | exit(2); |
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| 100 | } |
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| 101 | sprintf(tmpname, "/usr/tmp/atob.%x", getpid()); |
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| 102 | tmpfile = fopen(tmpname, "w+"); |
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| 103 | if (tmpfile == NULL) { |
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| 104 | fatal(); |
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| 105 | } |
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| 106 | /*search for header line*/ |
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| 107 | for (;;) { |
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| 108 | if (fgets(buf, sizeof buf, stdin) == NULL) { |
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| 109 | fatal(); |
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| 110 | } |
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| 111 | if (streq(buf, "xbtoa Begin\n")) { |
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| 112 | break; |
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| 113 | } |
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| 114 | } |
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| 115 | |
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| 116 | while ((c = getchar()) != EOF) { |
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| 117 | if (c == '\n') { |
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| 118 | continue; |
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| 119 | } |
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| 120 | else if (c == 'x') { |
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| 121 | break; |
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| 122 | } |
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| 123 | else{ |
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| 124 | decode(c); |
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| 125 | |
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| 126 | } |
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| 127 | } |
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| 128 | if (scanf("btoa End N %d %x E %x S %x R %x\n", &n1, &n2, &oeor, &osum, &orot) != 5) { |
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| 129 | fatal(); |
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| 130 | } |
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| 131 | if ((n1 != n2) || (oeor != Ceor) || (osum != Csum) || (orot != Crot)) { |
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| 132 | fatal(); |
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| 133 | } |
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| 134 | else{ |
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| 135 | /*copy OK tmp file to stdout*/; |
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| 136 | fseek(tmpfile, 0, 0); |
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| 137 | for (i = n1; --i >= 0;) { |
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| 138 | putchar(getc(tmpfile)); |
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| 139 | } |
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| 140 | unlink(tmpname); |
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| 141 | } |
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| 142 | } |
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