1 | /* |
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2 | * |
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3 | * Copyright (C) 1988, 1989 by the Massachusetts Institute of Technology |
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4 | * Developed by the MIT Student Information Processing Board (SIPB). |
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5 | * For copying information, see the file mit-copyright.h in this release. |
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6 | * |
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7 | */ |
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8 | /* |
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9 | * |
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10 | * $Id: tunix.c,v 1.8 1999-02-08 14:47:13 danw Exp $ |
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11 | * |
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12 | * tunix.c -- procedures to have tfiles work from unix files. |
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13 | * |
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14 | * |
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15 | */ |
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16 | #ifndef lint |
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17 | static char rcsid_tunix_c[] = |
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18 | "$Id: tunix.c,v 1.8 1999-02-08 14:47:13 danw Exp $"; |
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19 | #endif /* lint */ |
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20 | |
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21 | #define min(A, B) ((A) < (B) ? (A) : (B)) |
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22 | #define NIL 0 |
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23 | |
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24 | #define SUCCESS 1 |
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25 | |
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26 | #include <stdio.h> |
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27 | #include <discuss/tfile.h> |
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28 | #include <errno.h> |
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29 | #include <sys/types.h> |
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30 | #include <sys/stat.h> |
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31 | |
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32 | #define NL '\n' |
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33 | |
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34 | char *malloc(); |
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35 | |
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36 | extern int errno; |
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37 | |
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38 | struct tunix_state { |
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39 | char last_char; |
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40 | }; |
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41 | |
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42 | /* |
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43 | * |
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44 | * tunix () -- This is the handler procedure, that handles tfile requests. |
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45 | * |
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46 | */ |
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47 | int tunix (op, infop, info, argp, argn, result) |
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48 | int op, *info, argn, *result; |
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49 | char **infop, *argp; |
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50 | { |
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51 | int numread,numwrite; |
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52 | struct tunix_state *ts; |
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53 | |
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54 | *result = 0; /* optimist */ |
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55 | ts = (struct tunix_state *) *infop; |
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56 | |
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57 | switch (op) { |
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58 | case TFOPEN: /* argp is pointer to modes */ |
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59 | return (0); |
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60 | |
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61 | case TFCLOSE: |
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62 | return (0); |
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63 | |
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64 | case TFREAD: |
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65 | numread = read (*info, argp, argn); |
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66 | if (numread < 0) { |
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67 | *result = errno; |
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68 | return (-1); |
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69 | } |
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70 | return(numread); |
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71 | |
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72 | case TFWRITE: |
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73 | numwrite = write (*info, argp, argn); |
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74 | if (numwrite < 0) { |
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75 | *result = errno; |
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76 | return (-1); |
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77 | } |
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78 | /* save last character written to file, so we can force NL */ |
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79 | ts -> last_char = argp [numwrite-1]; |
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80 | return(numwrite); |
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81 | |
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82 | case TFDESTROY: |
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83 | free (*infop); |
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84 | return (0); |
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85 | |
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86 | case TFCONTROL: |
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87 | if (argn == TFC_FORCE_NL) { /* force a NL at this point */ |
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88 | if (ts -> last_char != NL) { |
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89 | ts -> last_char = NL; |
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90 | write (*info, &(ts -> last_char), 1); |
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91 | } |
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92 | } |
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93 | return (0); |
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94 | |
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95 | default: |
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96 | *result = EBADF; |
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97 | return (-1); |
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98 | } |
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99 | } |
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100 | |
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101 | /* |
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102 | * |
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103 | * unix_tfile (tfs, us) |
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104 | * |
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105 | */ |
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106 | tfile unix_tfile (desc) |
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107 | int desc; |
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108 | { |
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109 | struct stat buf; |
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110 | struct tunix_state *ts; |
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111 | |
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112 | if (fstat (desc, &buf) < 0) |
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113 | return (NIL); |
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114 | |
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115 | ts = (struct tunix_state *) malloc (sizeof (struct tunix_state)); |
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116 | ts -> last_char = 0; |
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117 | |
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118 | return (tcreate ((int) buf.st_size, (char *) ts, desc, tunix)); |
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119 | } |
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