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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 8687 | turbocat | 1 | /* |
| 2 | function for format read from any source |
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| 3 | |||
| 4 | Siemargl formats as http://www.cplusplus.com/reference/cstdio/scanf/, no wchar though |
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| 5 | http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap05.html is used too |
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| 6 | |||
| 7 | todo: |
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| 8 | [characters], [^characters] |
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| 9 | -%n nothing scanned, filled only if good result |
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| 10 | -%d, i, u, o, x, p read similar - detect base by prefix 0 or 0x |
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| 11 | -%a |
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| 12 | -can overflow unsigned as signed |
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| 13 | -radix point always '.', no LOCALEs |
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| 14 | */ |
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| 15 | |||
| 16 | #include |
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| 17 | #include |
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| 18 | #include |
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| 19 | #include |
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| 20 | #include "format_scan.h" |
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| 21 | |||
| 22 | static int __try_parse_real(long double *real, int ch, const void *src, void *save, virtual_getc vgetc, virtual_ungetc vungetc) |
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| 23 | // returns 1 if OK, -1 == EOF, -2 parse broken |
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| 24 | { |
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| 25 | int sign = 1, have_digits = 0; |
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| 26 | long long div; |
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| 27 | |||
| 28 | if (ch == '+') |
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| 29 | { |
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| 30 | ch = vgetc(save, src); |
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| 31 | if (ch == EOF) return EOF; |
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| 32 | } else |
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| 33 | if (ch == '-') |
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| 34 | { |
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| 35 | sign = -1; |
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| 36 | ch = vgetc(save, src); |
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| 37 | if (ch == EOF) return EOF; |
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| 38 | }; |
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| 39 | *real = 0.0; |
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| 40 | for (;;) // mantissa before point |
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| 41 | { |
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| 42 | // test ch is valid |
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| 43 | if (isdigit(ch)) |
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| 44 | { |
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| 45 | *real = *real * 10 + ch - '0'; |
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| 46 | have_digits++; |
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| 47 | ch = vgetc(save, src); |
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| 48 | if (ch == EOF || isspace(ch)) break; // ok, just finish num |
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| 49 | } else |
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| 50 | if (ch == '.' || ch == 'E' || ch == 'e') |
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| 51 | { |
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| 52 | break; // ok |
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| 53 | } |
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| 54 | else |
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| 55 | { |
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| 56 | vungetc(save, ch, src); |
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| 57 | break; |
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| 58 | } |
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| 59 | } |
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| 60 | if (ch != '.' && ch != 'E' && ch != 'e') // ok, just integer part |
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| 61 | { |
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| 62 | *real *= sign; |
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| 63 | if (have_digits) |
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| 64 | return 1; |
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| 65 | else |
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| 66 | return -2; |
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| 67 | } |
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| 68 | |||
| 69 | if(ch == '.') |
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| 70 | { |
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| 71 | ch = vgetc(save, src); |
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| 72 | div = 10; // use as divisor |
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| 73 | for (;;) // mantissa after point |
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| 74 | { |
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| 75 | // test ch is valid |
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| 76 | if (isdigit(ch)) |
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| 77 | { |
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| 78 | *real += (double)(ch - '0') / div; |
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| 79 | div *= 10; |
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| 80 | have_digits++; |
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| 81 | ch = vgetc(save, src); |
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| 82 | if (ch == EOF || isspace(ch)) break; // ok, just finish num |
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| 83 | } else |
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| 84 | if (ch == 'E' || ch == 'e') |
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| 85 | { |
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| 86 | break; // ok |
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| 87 | } |
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| 88 | else |
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| 89 | { |
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| 90 | vungetc(save, ch, src); |
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| 91 | break; |
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| 92 | } |
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| 93 | } |
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| 94 | if (ch != 'E' && ch != 'e') // ok, real as XX.YY |
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| 95 | { |
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| 96 | *real *= sign; |
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| 97 | if (have_digits) |
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| 98 | return 1; |
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| 99 | else |
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| 100 | return -2; |
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| 101 | } |
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| 102 | } |
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| 103 | |||
| 104 | ch = vgetc(save, src); |
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| 105 | *real *= sign; |
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| 106 | // exponent |
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| 107 | sign = 1; |
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| 108 | if (ch == '+') |
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| 109 | { |
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| 110 | ch = vgetc(save, src); |
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| 111 | if (ch == EOF) return EOF; |
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| 112 | } else |
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| 113 | if (ch == '-') |
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| 114 | { |
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| 115 | sign = -1; |
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| 116 | ch = vgetc(save, src); |
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| 117 | if (ch == EOF) return EOF; |
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| 118 | }; |
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| 119 | div = 0; |
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| 120 | for (;;) |
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| 121 | { |
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| 122 | // test ch is valid |
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| 123 | if (isdigit(ch)) |
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| 124 | { |
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| 125 | div = div * 10 + ch - '0'; |
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| 126 | ch = vgetc(save, src); |
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| 127 | if (ch == EOF || isspace(ch)) break; // ok, just finish num |
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| 128 | } |
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| 129 | else |
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| 130 | { |
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| 131 | vungetc(save, ch, src); |
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| 132 | break; |
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| 133 | } |
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| 134 | } |
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| 135 | div *= sign; |
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| 136 | *real *= pow(10,div); |
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| 137 | |||
| 138 | return 1; |
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| 139 | } |
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| 140 | |||
| 141 | static int __try_parse_int(long long *digit, int ch, const void *src, void *save, virtual_getc vgetc, virtual_ungetc vungetc) |
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| 142 | { |
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| 143 | int sign = 1, base = 10, have_digits = 0; |
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| 144 | |||
| 145 | if (ch == '+') |
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| 146 | { |
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| 147 | ch = vgetc(save, src); |
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| 148 | if (ch == EOF) return EOF; |
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| 149 | } else |
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| 150 | if (ch == '-') |
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| 151 | { |
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| 152 | sign = -1; |
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| 153 | ch = vgetc(save, src); |
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| 154 | if (ch == EOF) return EOF; |
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| 155 | }; |
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| 156 | |||
| 157 | if (ch == '0') // octal or hex, read next |
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| 158 | { |
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| 159 | base = 8; |
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| 160 | ch = vgetc(save, src); |
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| 161 | if (ch == EOF || isspace(ch)) |
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| 162 | have_digits++; |
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| 163 | else |
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| 164 | if (ch == 'x' || ch == 'X') |
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| 165 | { |
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| 166 | base = 16; |
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| 167 | ch = vgetc(save, src); |
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| 168 | if (ch == EOF) return EOF; |
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| 169 | } |
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| 170 | } |
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| 171 | *digit = 0; |
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| 172 | for (;;) |
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| 173 | { |
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| 174 | // test ch is valid |
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| 175 | if ((isdigit(ch) && base == 10) || |
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| 176 | (isdigit(ch) && base == 8 && ch < '8') || |
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| 177 | (isxdigit(ch) && base == 16)) |
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| 178 | { |
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| 179 | if (base == 16) |
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| 180 | { |
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| 181 | if (ch <= '9') ch-= '0'; |
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| 182 | else |
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| 183 | if (ch <= 'F') ch = 10 + ch - 'A'; |
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| 184 | else |
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| 185 | ch = 10 + ch - 'a'; |
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| 186 | } |
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| 187 | else |
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| 188 | ch -= '0'; |
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| 189 | *digit = *digit * base + ch; |
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| 190 | have_digits++; |
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| 191 | ch = vgetc(save, src); |
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| 192 | if (ch == EOF || isspace(ch)) break; // ok, just finish num |
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| 193 | } |
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| 194 | else if (ch == EOF || isspace(ch)) |
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| 195 | break; |
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| 196 | else |
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| 197 | { |
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| 198 | vungetc(save, ch, src); |
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| 199 | break; |
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| 200 | } |
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| 201 | } |
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| 202 | *digit *= sign; |
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| 203 | if (have_digits) |
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| 204 | return 1; |
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| 205 | else |
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| 206 | return -2; |
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| 207 | } |
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| 208 | |||
| 209 | |||
| 210 | |||
| 211 | int _format_scan(const void *src, const char *fmt, va_list argp, virtual_getc vgetc, virtual_ungetc vungetc) |
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| 212 | { |
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| 213 | int i; |
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| 214 | int length; |
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| 215 | int fmt1, fmt2; // width, precision |
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| 216 | size_t pos, posc; |
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| 217 | const char *fmtc; // first point to %, fmtc points to specifier |
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| 218 | int ch; |
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| 219 | int format_flag; |
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| 220 | int flag_long; // 2 = long double or long long int or wchar |
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| 221 | int *point_to_n = NULL, nread = 0; |
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| 222 | int flags; // parsed flags |
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| 223 | int save = 0; |
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| 224 | char *arg_str; |
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| 225 | int *arg_int; |
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| 226 | long *arg_long; |
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| 227 | long long *arg_longlong; |
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| 228 | float *arg_float; |
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| 229 | double *arg_double; |
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| 230 | long double *arg_longdouble; |
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| 231 | long long digit; |
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| 232 | long double real; |
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| 233 | |||
| 234 | |||
| 235 | pos = 0; |
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| 236 | while(*fmt) |
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| 237 | { |
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| 238 | while (*fmt && isspace(*fmt)) fmt++; // skip paces in format str |
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| 239 | |||
| 240 | if (*fmt != '%') // usual char |
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| 241 | { |
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| 242 | ch = vgetc(&save, src); |
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| 243 | if (ch != *fmt++) // char not match format |
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| 244 | { |
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| 245 | vungetc(&save, ch, src); |
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| 246 | break; |
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| 247 | } |
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| 248 | pos++; |
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| 249 | continue; |
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| 250 | } |
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| 251 | |||
| 252 | if (*(fmt + 1) == '%') // %% |
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| 253 | { |
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| 254 | ch = vgetc(&save, src); |
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| 255 | if (ch != '%') // char not match format |
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| 256 | { |
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| 257 | vungetc(&save, ch, src); |
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| 258 | break; |
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| 259 | } |
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| 260 | pos++; |
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| 261 | fmt += 2; |
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| 262 | continue; |
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| 263 | } |
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| 264 | //checking to containg format in the string |
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| 265 | fmtc = fmt; |
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| 266 | posc = pos; |
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| 267 | |||
| 268 | flags = 0; |
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| 269 | format_flag = 0; |
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| 270 | flag_long = 0; // 2 = long double or long long int or wchar |
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| 271 | |||
| 272 | while(*fmtc != '\0' && !format_flag) // searching end of format |
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| 273 | { |
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| 274 | fmtc++; posc++; |
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| 275 | switch( *fmtc ) |
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| 276 | { |
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| 277 | case 'a': |
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| 278 | format_flag = 1; |
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| 279 | flags |= flag_unsigned; |
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| 280 | break; |
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| 281 | case 'c': case 'd': case 'i': case 'e': case 'f': case 'g': case 's': case 'n': |
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| 282 | format_flag = 1; |
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| 283 | break; |
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| 284 | case 'l': |
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| 285 | flag_long = flag_long ? 2 : 1; // ll.eq.L |
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| 286 | break; |
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| 287 | case 'L': |
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| 288 | flag_long = 2; |
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| 289 | break; |
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| 290 | case 'o': case 'u': case 'x': case 'p': |
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| 291 | format_flag = 1; |
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| 292 | flags |= flag_unsigned; |
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| 293 | break; |
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| 294 | case '*': case '.': // just skip |
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| 295 | break; |
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| 296 | default: |
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| 297 | if(isdigit(*fmtc)) break; |
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| 298 | goto exit_me; // non format char found - user error |
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| 299 | } |
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| 300 | } |
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| 301 | |||
| 302 | if (format_flag == 0) |
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| 303 | { |
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| 304 | goto exit_me; // format char not found - user error |
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| 305 | } |
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| 306 | |||
| 307 | fmt1 = 0; |
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| 308 | fmt2 = 0; |
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| 309 | if (posc - pos > 1) // try to read width, precision |
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| 310 | { |
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| 311 | fmt++; |
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| 312 | for(i = pos + 1; i < posc; i++) |
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| 313 | { |
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| 314 | switch(*fmt) |
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| 315 | { |
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| 316 | case '0': |
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| 317 | if(fmt1 == 0 && (flags & flag_point) == 0) flags |= flag_lead_zeros; |
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| 318 | case '1': case '2': case '3': case '4': |
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| 319 | case '5': case '6': case '7': case '8': case '9': |
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| 320 | if ((flags & flag_point) == 0) |
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| 321 | fmt1 = fmt1 * 10 + (*fmt -'0'); |
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| 322 | else |
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| 323 | fmt2 = fmt2 * 10 + (*fmt -'0'); |
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| 324 | break; |
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| 325 | case '*': // ignoring |
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| 326 | break; |
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| 327 | case '.': |
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| 328 | flags |= flag_point; |
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| 329 | break; |
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| 330 | case 'l': case 'L': // valid chars - skip |
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| 331 | break; |
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| 332 | default: // must be error |
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| 333 | goto exit_me; // format char not found - user error |
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| 334 | } |
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| 335 | fmt++; |
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| 336 | } |
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| 337 | } |
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| 338 | |||
| 339 | // do real work - format arguments values |
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| 340 | // skip input spaces |
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| 341 | do { |
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| 342 | ch = vgetc(&save, src); |
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| 343 | if (ch == EOF) goto exit_me; |
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| 344 | } while (isspace(ch)); |
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| 345 | |||
| 346 | switch(*fmtc) |
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| 347 | { |
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| 348 | case 'n': |
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| 349 | point_to_n = va_arg(argp, int*); |
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| 350 | vungetc(&save, ch, src); |
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| 351 | break; |
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| 352 | case 'c': // read width chars, ever spaces |
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| 353 | arg_str = va_arg(argp, char*); |
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| 354 | if (fmt1 == 0) length = 1; |
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| 355 | else length = fmt1; |
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| 356 | for (i = 0; i < length;) |
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| 357 | { |
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| 358 | *arg_str++ = ch; i++; |
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| 359 | ch = vgetc(&save, src); |
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| 360 | if (ch == EOF) break; |
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| 361 | } |
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| 362 | if (i < length) goto exit_me; // not enough chars |
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| 363 | break; |
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| 364 | case 's': |
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| 365 | arg_str = va_arg(argp, char*); |
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| 366 | if (fmt1 == 0) length = STDIO_MAX_MEM; // max string scan 4096 |
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| 367 | else length = fmt1; |
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| 368 | for (i = 0; i < length; i++) |
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| 369 | { |
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| 370 | *arg_str++ = ch; |
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| 371 | ch = vgetc(&save, src); |
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| 372 | if (ch == EOF || isspace(ch)) break; // ok, just finish string |
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| 373 | } |
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| 374 | *arg_str++ = '\0'; |
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| 375 | break; |
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| 376 | case 'd': case 'i': case 'u': |
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| 377 | case 'o': case 'p': case 'x': |
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| 378 | i = __try_parse_int(&digit, ch, src, &save, vgetc, vungetc); |
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| 379 | if (i < 0) goto exit_me; |
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| 380 | |||
| 381 | if (flag_long == 0) { arg_int = va_arg(argp, int*); *arg_int = (int)digit; } else |
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| 382 | if (flag_long == 1) { arg_long = va_arg(argp, long*); *arg_long = (long)digit; } else |
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| 383 | if (flag_long == 2) { arg_longlong = va_arg(argp, long long*); *arg_longlong = digit; } |
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| 384 | break; |
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| 385 | case 'a': case 'A': case 'f': case 'F': |
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| 386 | case 'e': case 'E': |
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| 387 | case 'g': case 'G': |
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| 388 | i = __try_parse_real(&real, ch, src, &save, vgetc, vungetc); |
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| 389 | if (i < 0) goto exit_me; |
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| 390 | |||
| 391 | if (flag_long == 0) { arg_float = va_arg(argp, float*); *arg_float = (float)real; } else |
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| 392 | if (flag_long == 1) { arg_double = va_arg(argp, double*); *arg_double = (double)real; } else |
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| 393 | if (flag_long == 2) { arg_longdouble = va_arg(argp, long double*); *arg_longdouble = real; } |
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| 394 | break; |
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| 395 | } |
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| 396 | |||
| 397 | fmt = fmtc + 1; |
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| 398 | nread++; |
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| 399 | } |
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| 400 | exit_me: |
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| 401 | if (point_to_n) *point_to_n = nread; |
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| 402 | return nread; |
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| 403 | } |