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4349 | Serge | 1 | /* |
2 | * Copyright (c) 1990 The Regents of the University of California. |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms are permitted |
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6 | * provided that the above copyright notice and this paragraph are |
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7 | * duplicated in all such forms and that any documentation, |
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8 | * advertising materials, and other materials related to such |
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9 | * distribution and use acknowledge that the software was developed |
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10 | * by the University of California, Berkeley. The name of the |
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11 | * University may not be used to endorse or promote products derived |
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12 | * from this software without specific prior written permission. |
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13 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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14 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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16 | */ |
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17 | |||
18 | /* |
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19 | FUNCTION |
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20 | < |
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21 | |||
22 | INDEX |
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23 | fgets |
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24 | INDEX |
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25 | _fgets_r |
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26 | |||
27 | ANSI_SYNOPSIS |
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28 | #include |
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29 | char *fgets(char *<[buf]>, int <[n]>, FILE *<[fp]>); |
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30 | |||
31 | #include |
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32 | char *_fgets_r(struct _reent *<[ptr]>, char *<[buf]>, int <[n]>, FILE *<[fp]>); |
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33 | |||
34 | TRAD_SYNOPSIS |
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35 | #include |
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36 | char *fgets(<[buf]>,<[n]>,<[fp]>) |
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37 | char *<[buf]>; |
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38 | int <[n]>; |
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39 | FILE *<[fp]>; |
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40 | |||
41 | #include |
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42 | char *_fgets_r(<[ptr]>, <[buf]>,<[n]>,<[fp]>) |
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43 | struct _reent *<[ptr]>; |
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44 | char *<[buf]>; |
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45 | int <[n]>; |
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46 | FILE *<[fp]>; |
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47 | |||
48 | DESCRIPTION |
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49 | Reads at most <[n-1]> characters from <[fp]> until a newline |
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50 | is found. The characters including to the newline are stored |
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51 | in <[buf]>. The buffer is terminated with a 0. |
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52 | |||
53 | The <<_fgets_r>> function is simply the reentrant version of |
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54 | < |
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55 | pointer: <[ptr]>. |
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56 | |||
57 | RETURNS |
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58 | < |
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59 | filled in. If end of file occurs with some data already |
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60 | accumulated, the data is returned with no other indication. If |
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61 | no data are read, NULL is returned instead. |
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62 | |||
63 | PORTABILITY |
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64 | < |
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65 | that < |
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66 | the trailing newline (with no indication that it has done so.) |
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67 | |||
68 | Supporting OS subroutines required: < |
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69 | < |
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70 | */ |
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71 | |||
72 | #include <_ansi.h> |
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73 | #include |
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74 | #include |
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75 | #include "local.h" |
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76 | |||
77 | /* |
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78 | * Read at most n-1 characters from the given file. |
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79 | * Stop when a newline has been read, or the count runs out. |
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80 | * Return first argument, or NULL if no characters were read. |
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81 | */ |
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82 | |||
83 | char * |
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84 | _DEFUN(_fgets_r, (ptr, buf, n, fp), |
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85 | struct _reent * ptr _AND |
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86 | char *buf _AND |
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87 | int n _AND |
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88 | FILE * fp) |
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89 | { |
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90 | size_t len; |
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91 | char *s; |
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92 | unsigned char *p, *t; |
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93 | |||
94 | if (n < 2) /* sanity check */ |
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95 | return 0; |
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96 | |||
97 | s = buf; |
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98 | |||
99 | CHECK_INIT(ptr, fp); |
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100 | |||
101 | _flockfile (fp); |
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102 | #ifdef __SCLE |
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103 | if (fp->_flags & __SCLE) |
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104 | { |
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105 | int c; |
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106 | /* Sorry, have to do it the slow way */ |
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107 | while (--n > 0 && (c = __sgetc_r (ptr, fp)) != EOF) |
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108 | { |
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109 | *s++ = c; |
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110 | if (c == '\n') |
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111 | break; |
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112 | } |
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113 | if (c == EOF && s == buf) |
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114 | { |
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115 | _funlockfile (fp); |
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116 | return NULL; |
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117 | } |
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118 | *s = 0; |
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119 | _funlockfile (fp); |
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120 | return buf; |
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121 | } |
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122 | #endif |
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123 | |||
124 | n--; /* leave space for NUL */ |
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125 | do |
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126 | { |
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127 | /* |
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128 | * If the buffer is empty, refill it. |
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129 | */ |
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130 | if ((len = fp->_r) <= 0) |
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131 | { |
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132 | if (__srefill_r (ptr, fp)) |
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133 | { |
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134 | /* EOF: stop with partial or no line */ |
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135 | if (s == buf) |
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136 | { |
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137 | _funlockfile (fp); |
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138 | return 0; |
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139 | } |
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140 | break; |
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141 | } |
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142 | len = fp->_r; |
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143 | } |
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144 | p = fp->_p; |
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145 | |||
146 | /* |
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147 | * Scan through at most n bytes of the current buffer, |
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148 | * looking for '\n'. If found, copy up to and including |
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149 | * newline, and stop. Otherwise, copy entire chunk |
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150 | * and loop. |
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151 | */ |
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152 | if (len > n) |
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153 | len = n; |
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154 | t = (unsigned char *) memchr ((_PTR) p, '\n', len); |
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155 | if (t != 0) |
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156 | { |
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157 | len = ++t - p; |
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158 | fp->_r -= len; |
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159 | fp->_p = t; |
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160 | _CAST_VOID memcpy ((_PTR) s, (_PTR) p, len); |
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161 | s[len] = 0; |
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162 | _funlockfile (fp); |
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163 | return (buf); |
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164 | } |
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165 | fp->_r -= len; |
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166 | fp->_p += len; |
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167 | _CAST_VOID memcpy ((_PTR) s, (_PTR) p, len); |
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168 | s += len; |
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169 | } |
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170 | while ((n -= len) != 0); |
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171 | *s = 0; |
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172 | _funlockfile (fp); |
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173 | return buf; |
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174 | } |
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175 | |||
176 | #ifndef _REENT_ONLY |
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177 | |||
178 | char * |
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179 | _DEFUN(fgets, (buf, n, fp), |
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180 | char *buf _AND |
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181 | int n _AND |
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182 | FILE * fp) |
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183 | { |
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184 | return _fgets_r (_REENT, buf, n, fp); |
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185 | } |
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186 | |||
187 | #endif /* !_REENT_ONLY */=>> |