root / prex-0.9.0 / usr / lib / libc / stdio / vfscanf.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*-
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2 | * Copyright (c) 1990, 1993
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3 | * The Regents of the University of California. All rights reserved.
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4 | *
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5 | * This code is derived from software contributed to Berkeley by
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6 | * Chris Torek.
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7 | *
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8 | * Redistribution and use in source and binary forms, with or without
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9 | * modification, are permitted provided that the following conditions
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10 | * are met:
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11 | * 1. Redistributions of source code must retain the above copyright
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12 | * notice, this list of conditions and the following disclaimer.
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13 | * 2. Redistributions in binary form must reproduce the above copyright
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14 | * notice, this list of conditions and the following disclaimer in the
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15 | * documentation and/or other materials provided with the distribution.
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16 | * 3. Neither the name of the University nor the names of its contributors
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17 | * may be used to endorse or promote products derived from this software
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18 | * without specific prior written permission.
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19 | *
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20 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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21 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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22 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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23 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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24 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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25 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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26 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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27 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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28 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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29 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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30 | * SUCH DAMAGE.
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31 | */
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32 | |||
33 | #include <stdio.h> |
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34 | #include <stdlib.h> |
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35 | #include <ctype.h> |
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36 | #include <stdarg.h> |
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37 | #include "local.h" |
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38 | |||
39 | #define BUF 513 /* Maximum length of numeric string. */ |
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40 | |||
41 | /*
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42 | * Flags used during conversion.
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43 | */
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44 | #define LONG 0x01 /* l: long or double */ |
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45 | #define LONGDBL 0x02 /* L: long double; unimplemented */ |
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46 | #define SHORT 0x04 /* h: short */ |
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47 | #define SUPPRESS 0x08 /* suppress assignment */ |
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48 | #define POINTER 0x10 /* weird %p pointer (`fake hex') */ |
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49 | #define NOSKIP 0x20 /* do not skip blanks */ |
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50 | |||
51 | /*
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52 | * The following are used in numeric conversions only:
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53 | * SIGNOK, NDIGITS, DPTOK, and EXPOK are for floating point;
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54 | * SIGNOK, NDIGITS, PFXOK, and NZDIGITS are for integral.
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55 | */
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56 | #define SIGNOK 0x40 /* +/- is (still) legal */ |
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57 | #define NDIGITS 0x80 /* no digits detected */ |
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58 | |||
59 | #define DPTOK 0x100 /* (float) decimal point is still legal */ |
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60 | #define EXPOK 0x200 /* (float) exponent (e+3, etc) still legal */ |
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61 | |||
62 | #define PFXOK 0x100 /* 0x prefix is (still) legal */ |
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63 | #define NZDIGITS 0x200 /* no zero digits detected */ |
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64 | |||
65 | /*
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66 | * Conversion types.
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67 | */
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68 | #define CT_CHAR 0 /* %c conversion */ |
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69 | #define CT_CCL 1 /* %[...] conversion */ |
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70 | #define CT_STRING 2 /* %s conversion */ |
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71 | #define CT_INT 3 /* integer, i.e., strtol or strtoul */ |
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72 | #define CT_FLOAT 4 /* floating, i.e., strtod */ |
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73 | |||
74 | #define u_char unsigned char |
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75 | #define u_long unsigned long |
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76 | |||
77 | static u_char *__sccl(char *, u_char *); |
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78 | |||
79 | /*
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80 | * vfscanf
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81 | */
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82 | int
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83 | __svfscanf(fp, fmt0, ap) |
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84 | FILE *fp; |
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85 | char const *fmt0; |
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86 | va_list ap; |
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87 | { |
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88 | u_char *fmt = (u_char *)fmt0; |
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89 | int c; /* character from format, or conversion */ |
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90 | size_t width; /* field width, or 0 */
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91 | char *p; /* points into all kinds of strings */ |
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92 | int n; /* handy integer */ |
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93 | int flags; /* flags as defined above */ |
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94 | char *p0; /* saves original value of p when necessary */ |
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95 | int nassigned; /* number of fields assigned */ |
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96 | int nread; /* number of characters consumed from fp */ |
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97 | int base; /* base argument to strtol/strtoul */ |
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98 | u_long (*ccfn)(const char *, char **, int); |
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99 | /* conversion function (strtol/strtoul) */
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100 | char ccltab[256]; /* character class table for %[...] */ |
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101 | char buf[BUF]; /* buffer for numeric conversions */ |
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102 | |||
103 | /* `basefix' is used to avoid `if' tests in the integer scanner */
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104 | static short basefix[17] = |
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105 | { 10, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 }; |
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106 | |||
107 | nassigned = 0;
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108 | nread = 0;
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109 | base = 0; /* XXX just to keep gcc happy */ |
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110 | ccfn = 0; /* XXX just to keep gcc happy */ |
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111 | for (;;) {
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112 | c = *fmt++; |
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113 | if (c == 0) |
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114 | return (nassigned);
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115 | if (isspace(c)) {
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116 | for (;;) {
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117 | if (fp->_r <= 0 && __srefill(fp)) |
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118 | return (nassigned);
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119 | if (!isspace(*fp->_p))
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120 | break;
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121 | nread++, fp->_r--, fp->_p++; |
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122 | } |
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123 | continue;
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124 | } |
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125 | if (c != '%') |
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126 | goto literal;
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127 | width = 0;
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128 | flags = 0;
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129 | /*
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130 | * switch on the format. continue if done;
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131 | * break once format type is derived.
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132 | */
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133 | again: c = *fmt++;
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134 | switch (c) {
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135 | case '%': |
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136 | literal:
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137 | if (fp->_r <= 0 && __srefill(fp)) |
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138 | goto input_failure;
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139 | if (*fp->_p != c)
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140 | goto match_failure;
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141 | fp->_r--, fp->_p++; |
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142 | nread++; |
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143 | continue;
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144 | |||
145 | case '*': |
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146 | flags |= SUPPRESS; |
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147 | goto again;
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148 | case 'l': |
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149 | flags |= LONG; |
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150 | goto again;
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151 | case 'L': |
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152 | flags |= LONGDBL; |
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153 | goto again;
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154 | case 'h': |
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155 | flags |= SHORT; |
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156 | goto again;
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157 | |||
158 | case '0': case '1': case '2': case '3': case '4': |
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159 | case '5': case '6': case '7': case '8': case '9': |
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160 | width = width * 10 + c - '0'; |
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161 | goto again;
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162 | |||
163 | /*
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164 | * Conversions.
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165 | * Those marked `compat' are for 4.[123]BSD compatibility.
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166 | *
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167 | * (According to ANSI, E and X formats are supposed
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168 | * to the same as e and x. Sorry about that.)
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169 | */
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170 | case 'D': /* compat */ |
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171 | flags |= LONG; |
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172 | /* FALLTHROUGH */
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173 | case 'd': |
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174 | c = CT_INT; |
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175 | ccfn = (u_long (*)(const char *, char **, int))strtol; |
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176 | base = 10;
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177 | break;
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178 | |||
179 | case 'i': |
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180 | c = CT_INT; |
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181 | ccfn = (u_long (*)(const char *, char **, int))strtol; |
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182 | base = 0;
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183 | break;
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184 | |||
185 | case 'O': /* compat */ |
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186 | flags |= LONG; |
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187 | /* FALLTHROUGH */
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188 | case 'o': |
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189 | c = CT_INT; |
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190 | ccfn = strtoul; |
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191 | base = 8;
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192 | break;
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193 | |||
194 | case 'u': |
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195 | c = CT_INT; |
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196 | ccfn = strtoul; |
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197 | base = 10;
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198 | break;
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199 | |||
200 | case 'X': /* compat XXX */ |
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201 | flags |= LONG; |
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202 | /* FALLTHROUGH */
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203 | case 'x': |
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204 | flags |= PFXOK; /* enable 0x prefixing */
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205 | c = CT_INT; |
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206 | ccfn = strtoul; |
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207 | base = 16;
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208 | break;
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209 | |||
210 | case 's': |
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211 | c = CT_STRING; |
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212 | break;
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213 | |||
214 | case '[': |
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215 | fmt = __sccl(ccltab, fmt); |
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216 | flags |= NOSKIP; |
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217 | c = CT_CCL; |
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218 | break;
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219 | |||
220 | case 'c': |
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221 | flags |= NOSKIP; |
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222 | c = CT_CHAR; |
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223 | break;
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224 | |||
225 | case 'p': /* pointer format is like hex */ |
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226 | flags |= POINTER | PFXOK; |
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227 | c = CT_INT; |
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228 | ccfn = strtoul; |
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229 | base = 16;
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230 | break;
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231 | |||
232 | case 'n': |
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233 | if (flags & SUPPRESS) /* ??? */ |
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234 | continue;
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235 | if (flags & SHORT)
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236 | *va_arg(ap, short *) = nread;
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237 | else if (flags & LONG) |
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238 | *va_arg(ap, long *) = nread;
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239 | else
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240 | *va_arg(ap, int *) = nread;
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241 | continue;
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242 | |||
243 | /*
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244 | * Disgusting backwards compatibility hacks. XXX
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245 | */
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246 | case '\0': /* compat */ |
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247 | return (EOF); |
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248 | |||
249 | default: /* compat */ |
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250 | if (isupper(c))
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251 | flags |= LONG; |
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252 | c = CT_INT; |
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253 | ccfn = (u_long (*)(const char *, char **, int))strtol; |
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254 | base = 10;
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255 | break;
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256 | } |
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257 | |||
258 | /*
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259 | * We have a conversion that requires input.
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260 | */
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261 | if (fp->_r <= 0 && __srefill(fp)) |
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262 | goto input_failure;
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263 | |||
264 | /*
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265 | * Consume leading white space, except for formats
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266 | * that suppress this.
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267 | */
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268 | if ((flags & NOSKIP) == 0) { |
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269 | while (isspace(*fp->_p)) {
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270 | nread++; |
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271 | if (--fp->_r > 0) |
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272 | fp->_p++; |
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273 | else if (__srefill(fp)) |
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274 | goto input_failure;
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275 | } |
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276 | /*
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277 | * Note that there is at least one character in
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278 | * the buffer, so conversions that do not set NOSKIP
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279 | * ca no longer result in an input failure.
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280 | */
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281 | } |
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282 | |||
283 | /*
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284 | * Do the conversion.
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285 | */
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286 | switch (c) {
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287 | |||
288 | case CT_CHAR:
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289 | /* scan arbitrary characters (sets NOSKIP) */
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290 | if (width == 0) |
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291 | width = 1;
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292 | if (flags & SUPPRESS) {
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293 | size_t sum = 0;
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294 | for (;;) {
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295 | if ((size_t)(n = fp->_r) < width) {
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296 | sum += n; |
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297 | width -= n; |
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298 | fp->_p += n; |
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299 | if (__srefill(fp)) {
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300 | if (sum == 0) |
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301 | goto input_failure;
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302 | break;
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303 | } |
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304 | } else {
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305 | sum += width; |
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306 | fp->_r -= width; |
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307 | fp->_p += width; |
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308 | break;
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309 | } |
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310 | } |
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311 | nread += sum; |
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312 | } else {
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313 | size_t r = fread((void *)va_arg(ap, char *), 1, |
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314 | width, fp); |
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315 | |||
316 | if (r == 0) |
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317 | goto input_failure;
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318 | nread += r; |
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319 | nassigned++; |
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320 | } |
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321 | break;
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322 | |||
323 | case CT_CCL:
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324 | /* scan a (nonempty) character class (sets NOSKIP) */
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325 | if (width == 0) |
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326 | width = ~0; /* `infinity' */ |
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327 | /* take only those things in the class */
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328 | if (flags & SUPPRESS) {
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329 | n = 0;
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330 | while (ccltab[*fp->_p]) {
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331 | n++, fp->_r--, fp->_p++; |
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332 | if (--width == 0) |
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333 | break;
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334 | if (fp->_r <= 0 && __srefill(fp)) { |
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335 | if (n == 0) |
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336 | goto input_failure;
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337 | break;
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338 | } |
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339 | } |
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340 | if (n == 0) |
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341 | goto match_failure;
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342 | } else {
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343 | p0 = p = va_arg(ap, char *);
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344 | while (ccltab[*fp->_p]) {
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345 | fp->_r--; |
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346 | *p++ = *fp->_p++; |
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347 | if (--width == 0) |
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348 | break;
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349 | if (fp->_r <= 0 && __srefill(fp)) { |
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350 | if (p == p0)
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351 | goto input_failure;
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352 | break;
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353 | } |
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354 | } |
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355 | n = p - p0; |
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356 | if (n == 0) |
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357 | goto match_failure;
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358 | *p = 0;
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359 | nassigned++; |
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360 | } |
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361 | nread += n; |
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362 | break;
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363 | |||
364 | case CT_STRING:
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365 | /* like CCL, but zero-length string OK, & no NOSKIP */
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366 | if (width == 0) |
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367 | width = ~0;
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368 | if (flags & SUPPRESS) {
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369 | n = 0;
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370 | while (!isspace(*fp->_p)) {
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371 | n++, fp->_r--, fp->_p++; |
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372 | if (--width == 0) |
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373 | break;
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374 | if (fp->_r <= 0 && __srefill(fp)) |
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375 | break;
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376 | } |
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377 | nread += n; |
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378 | } else {
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379 | p0 = p = va_arg(ap, char *);
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380 | while (!isspace(*fp->_p)) {
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381 | fp->_r--; |
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382 | *p++ = *fp->_p++; |
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383 | if (--width == 0) |
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384 | break;
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385 | if (fp->_r <= 0 && __srefill(fp)) |
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386 | break;
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387 | } |
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388 | *p = 0;
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389 | nread += p - p0; |
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390 | nassigned++; |
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391 | } |
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392 | continue;
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393 | |||
394 | case CT_INT:
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395 | /* scan an integer as if by strtol/strtoul */
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396 | #ifdef hardway
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397 | if (width == 0 || width > sizeof(buf) - 1) |
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398 | width = sizeof(buf) - 1; |
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399 | #else
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400 | /* size_t is unsigned, hence this optimisation */
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401 | if (--width > sizeof(buf) - 2) |
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402 | width = sizeof(buf) - 2; |
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403 | width++; |
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404 | #endif
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405 | flags |= SIGNOK | NDIGITS | NZDIGITS; |
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406 | for (p = buf; width; width--) {
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407 | c = *fp->_p; |
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408 | /*
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409 | * Switch on the character; `goto ok'
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410 | * if we accept it as a part of number.
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411 | */
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412 | switch (c) {
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413 | |||
414 | /*
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415 | * The digit 0 is always legal, but is
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416 | * special. For %i conversions, if no
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417 | * digits (zero or nonzero) have been
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418 | * scanned (only signs), we will have
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419 | * base==0. In that case, we should set
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420 | * it to 8 and enable 0x prefixing.
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421 | * Also, if we have not scanned zero digits
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422 | * before this, do not turn off prefixing
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423 | * (someone else will turn it off if we
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424 | * have scanned any nonzero digits).
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425 | */
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426 | case '0': |
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427 | if (base == 0) { |
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428 | base = 8;
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429 | flags |= PFXOK; |
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430 | } |
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431 | if (flags & NZDIGITS)
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432 | flags &= ~(SIGNOK|NZDIGITS|NDIGITS); |
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433 | else
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434 | flags &= ~(SIGNOK|PFXOK|NDIGITS); |
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435 | goto ok;
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436 | |||
437 | /* 1 through 7 always legal */
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438 | case '1': case '2': case '3': |
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439 | case '4': case '5': case '6': case '7': |
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440 | base = basefix[base]; |
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441 | flags &= ~(SIGNOK | PFXOK | NDIGITS); |
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442 | goto ok;
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443 | |||
444 | /* digits 8 and 9 ok iff decimal or hex */
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445 | case '8': case '9': |
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446 | base = basefix[base]; |
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447 | if (base <= 8) |
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448 | break; /* not legal here */ |
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449 | flags &= ~(SIGNOK | PFXOK | NDIGITS); |
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450 | goto ok;
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451 | |||
452 | /* letters ok iff hex */
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453 | case 'A': case 'B': case 'C': |
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454 | case 'D': case 'E': case 'F': |
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455 | case 'a': case 'b': case 'c': |
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456 | case 'd': case 'e': case 'f': |
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457 | /* no need to fix base here */
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458 | if (base <= 10) |
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459 | break; /* not legal here */ |
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460 | flags &= ~(SIGNOK | PFXOK | NDIGITS); |
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461 | goto ok;
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462 | |||
463 | /* sign ok only as first character */
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464 | case '+': case '-': |
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465 | if (flags & SIGNOK) {
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466 | flags &= ~SIGNOK; |
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467 | goto ok;
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468 | } |
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469 | break;
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470 | |||
471 | /* x ok iff flag still set & 2nd char */
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472 | case 'x': case 'X': |
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473 | if (flags & PFXOK && p == buf + 1) { |
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474 | base = 16; /* if %i */ |
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475 | flags &= ~PFXOK; |
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476 | goto ok;
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477 | } |
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478 | break;
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479 | } |
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480 | |||
481 | /*
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482 | * If we got here, c is not a legal character
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483 | * for a number. Stop accumulating digits.
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484 | */
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485 | break;
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486 | ok:
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487 | /*
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488 | * c is legal: store it and look at the next.
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489 | */
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490 | *p++ = c; |
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491 | if (--fp->_r > 0) |
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492 | fp->_p++; |
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493 | else if (__srefill(fp)) |
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494 | break; /* EOF */ |
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495 | } |
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496 | /*
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497 | * If we had only a sign, it is no good; push
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498 | * back the sign. If the number ends in `x',
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499 | * it was [sign] '0' 'x', so push back the x
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500 | * and treat it as [sign] '0'.
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501 | */
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502 | if (flags & NDIGITS) {
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503 | if (p > buf)
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504 | (void) ungetc(*(u_char *)--p, fp);
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505 | goto match_failure;
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506 | } |
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507 | c = ((u_char *)p)[-1];
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508 | if (c == 'x' || c == 'X') { |
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509 | --p; |
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510 | (void) ungetc(c, fp);
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511 | } |
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512 | if ((flags & SUPPRESS) == 0) { |
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513 | u_long res; |
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514 | |||
515 | *p = 0;
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516 | res = (*ccfn)(buf, (char **)NULL, base); |
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517 | if (flags & POINTER)
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518 | *va_arg(ap, void **) = (void *)res; |
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519 | else if (flags & SHORT) |
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520 | *va_arg(ap, short *) = res;
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521 | else if (flags & LONG) |
||
522 | *va_arg(ap, long *) = res;
|
||
523 | else
|
||
524 | *va_arg(ap, int *) = res;
|
||
525 | nassigned++; |
||
526 | } |
||
527 | nread += p - buf; |
||
528 | break;
|
||
529 | |||
530 | } |
||
531 | } |
||
532 | input_failure:
|
||
533 | return (nassigned ? nassigned : -1); |
||
534 | match_failure:
|
||
535 | return (nassigned);
|
||
536 | } |
||
537 | |||
538 | /*
|
||
539 | * Fill in the given table from the scanset at the given format
|
||
540 | * (just after `['). Return a pointer to the character past the
|
||
541 | * closing `]'. The table has a 1 wherever characters should be
|
||
542 | * considered part of the scanset.
|
||
543 | */
|
||
544 | static u_char *
|
||
545 | __sccl(tab, fmt) |
||
546 | char *tab;
|
||
547 | u_char *fmt; |
||
548 | { |
||
549 | int c, n, v;
|
||
550 | |||
551 | /* first `clear' the whole table */
|
||
552 | c = *fmt++; /* first char hat => negated scanset */
|
||
553 | if (c == '^') { |
||
554 | v = 1; /* default => accept */ |
||
555 | c = *fmt++; /* get new first char */
|
||
556 | } else
|
||
557 | v = 0; /* default => reject */ |
||
558 | /* should probably use memset here */
|
||
559 | for (n = 0; n < 256; n++) |
||
560 | tab[n] = v; |
||
561 | if (c == 0) |
||
562 | return (fmt - 1);/* format ended before closing ] */ |
||
563 | |||
564 | /*
|
||
565 | * Now set the entries corresponding to the actual scanset
|
||
566 | * to the opposite of the above.
|
||
567 | *
|
||
568 | * The first character may be ']' (or '-') without being special;
|
||
569 | * the last character may be '-'.
|
||
570 | */
|
||
571 | v = 1 - v;
|
||
572 | for (;;) {
|
||
573 | tab[c] = v; /* take character c */
|
||
574 | doswitch:
|
||
575 | n = *fmt++; /* and examine the next */
|
||
576 | switch (n) {
|
||
577 | |||
578 | case 0: /* format ended too soon */ |
||
579 | return (fmt - 1); |
||
580 | |||
581 | case '-': |
||
582 | /*
|
||
583 | * A scanset of the form
|
||
584 | * [01+-]
|
||
585 | * is defined as `the digit 0, the digit 1,
|
||
586 | * the character +, the character -', but
|
||
587 | * the effect of a scanset such as
|
||
588 | * [a-zA-Z0-9]
|
||
589 | * is implementation defined. The V7 Unix
|
||
590 | * scanf treats `a-z' as `the letters a through
|
||
591 | * z', but treats `a-a' as `the letter a, the
|
||
592 | * character -, and the letter a'.
|
||
593 | *
|
||
594 | * For compatibility, the `-' is not considerd
|
||
595 | * to define a range if the character following
|
||
596 | * it is either a close bracket (required by ANSI)
|
||
597 | * or is not numerically greater than the character
|
||
598 | * we just stored in the table (c).
|
||
599 | */
|
||
600 | n = *fmt; |
||
601 | if (n == ']' || n < c) { |
||
602 | c = '-';
|
||
603 | break; /* resume the for(;;) */ |
||
604 | } |
||
605 | fmt++; |
||
606 | do { /* fill in the range */ |
||
607 | tab[++c] = v; |
||
608 | } while (c < n);
|
||
609 | #if 1 /* XXX another disgusting compatibility hack */ |
||
610 | /*
|
||
611 | * Alas, the V7 Unix scanf also treats formats
|
||
612 | * such as [a-c-e] as `the letters a through e'.
|
||
613 | * This too is permitted by the standard....
|
||
614 | */
|
||
615 | goto doswitch;
|
||
616 | #else
|
||
617 | c = *fmt++; |
||
618 | if (c == 0) |
||
619 | return (fmt - 1); |
||
620 | if (c == ']') |
||
621 | return (fmt);
|
||
622 | #endif
|
||
623 | break;
|
||
624 | |||
625 | case ']': /* end of scanset */ |
||
626 | return (fmt);
|
||
627 | |||
628 | default: /* just another character */ |
||
629 | c = n; |
||
630 | break;
|
||
631 | } |
||
632 | } |
||
633 | /* NOTREACHED */
|
||
634 | } |