1 #include "str.h" |
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2 |
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3 #include <ctype.h> |
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4 #include <stdio.h> |
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5 #include <string.h> |
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6 #include <stdbool.h> |
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7 |
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8 #include <assert.h> |
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9 |
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10 size_t str_append_num (char *buf, size_t buf_size, const char *str, ssize_t len) |
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11 { |
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12 size_t str_len; |
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13 |
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14 // copy the bytes |
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15 // len will either be >0 or <0 |
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16 for (str_len = 0; *str && buf_size > 1 && len != 0; str_len++, buf_size--, len--) |
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17 *buf++ = *str++; |
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18 |
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19 // count the rest |
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20 for (; *str && len != 0; str++, len--) |
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21 str_len++; |
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22 |
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23 if (buf_size) |
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24 // NUL-terminate |
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25 *buf = '\0'; |
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26 |
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27 // ok |
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28 return str_len; |
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29 |
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30 } |
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31 |
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32 size_t str_append (char *buf, size_t buf_size, const char *str) |
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33 { |
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34 return str_append_num(buf, buf_size, str, -1); |
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35 } |
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36 |
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37 size_t str_append_char (char *buf, size_t buf_size, char c) |
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38 { |
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39 if (buf_size > 1) |
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40 *buf++ = c; |
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41 |
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42 if (buf_size > 0) |
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43 *buf = '\0'; |
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44 |
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45 return 1; |
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46 } |
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47 |
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48 size_t str_append_fmt_va (char *buf, size_t buf_size, const char *fmt, va_list vargs) |
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49 { |
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50 int ret; |
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51 |
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52 // do the formatting |
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53 ret = vsnprintf(buf, buf_size, fmt, vargs); |
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54 |
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55 // XXX: not all vsnprintf implementations do this |
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56 assert(ret >= 0); |
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57 |
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58 // ok |
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59 return ret; |
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60 } |
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61 |
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62 size_t str_append_fmt (char *buf, size_t buf_size, const char *fmt, ...) |
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63 { |
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64 va_list vargs; |
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65 int ret; |
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66 |
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67 va_start(vargs, fmt); |
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68 ret = str_append_fmt_va(buf, buf_size, fmt, vargs); |
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69 va_end(vargs); |
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70 |
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71 return ret; |
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72 } |
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73 |
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74 static const struct str_quote_item { |
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75 /** The char value to quote */ |
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76 char c; |
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77 |
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78 /** The quoted value */ |
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79 const char *out; |
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80 } _quote_table[] = { |
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81 { '\'', "\\'" }, |
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82 { '\\', "\\\\" }, |
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83 { '\0', "\\0" }, |
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84 { '\r', "\\r" }, |
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85 { '\n', "\\n" }, |
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86 { 0, NULL } |
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87 }; |
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88 |
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89 size_t str_quote_char (char *buf, size_t buf_size, char c) |
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90 { |
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91 const struct str_quote_item *quote_item = _quote_table; |
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92 |
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93 // special quote? |
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94 for (quote_item = _quote_table; quote_item->c || quote_item->out; quote_item++) { |
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95 if (quote_item->c == c) |
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96 return str_append(buf, buf_size, quote_item->out); |
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97 } |
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98 |
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99 // output directly? |
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100 if (isprint(c)) |
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101 return str_append_char(buf, buf_size, c); |
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102 |
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103 else |
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104 return str_append_fmt(buf, buf_size, "\\x%02x", c); |
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105 } |
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106 |
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107 size_t str_advance (size_t *data_size, size_t *buf_size, size_t len) |
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108 { |
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109 if (data_size) |
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110 *data_size += len; |
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111 |
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112 if (len > *buf_size) |
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113 *buf_size = 0; |
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114 |
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115 else |
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116 *buf_size -= len; |
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117 |
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118 return len; |
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119 } |
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120 |
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121 /** |
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122 * Number of bytes reserved by str_quote for the trailing overflow stuff |
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123 */ |
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124 #define STR_QUOTE_RESERVED 5 |
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125 |
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126 size_t str_quote (char *buf, size_t buf_size, const char *str, ssize_t str_len) |
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127 { |
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128 size_t data_size = 0; |
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129 |
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130 // NULL? |
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131 if (str == NULL) { |
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132 return str_append(buf, buf_size, "NULL"); |
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133 |
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134 } else { |
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135 // calc length? |
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136 if (str_len < 0) |
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137 str_len = strlen(str); |
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138 |
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139 // quote |
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140 buf += str_advance(&data_size, &buf_size, str_append_char(buf, buf_size, '\'')); |
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141 |
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142 // dump each char |
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143 while (str_len--) { |
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144 if (buf_size > STR_QUOTE_RESERVED) { |
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145 size_t char_size; |
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146 |
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147 // output and count the chars |
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148 char_size = str_quote_char(buf, buf_size, *str++); |
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149 |
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150 // if there's still enough room left, commit this and continue |
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151 if (buf_size > char_size && buf_size - char_size >= STR_QUOTE_RESERVED) |
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152 buf += str_advance(&data_size, &buf_size, char_size); |
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153 |
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154 else |
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155 // keep the buf pointer intact, we'll overwrite it now |
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156 data_size += char_size; |
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157 |
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158 } else { |
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159 // continue counting the chars, but don't output anything anymore |
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160 data_size += str_quote_char(NULL, 0, *str++); |
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161 } |
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162 } |
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163 |
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164 // end quote |
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165 buf += str_advance(&data_size, &buf_size, str_append_char(buf, buf_size, '\'')); |
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166 } |
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167 |
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168 // overflow -> mark |
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169 if (buf_size < STR_QUOTE_RESERVED) |
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170 buf += str_advance(NULL, &buf_size, str_append(buf, buf_size, "...")); |
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171 |
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172 // the total outputted chars |
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173 return data_size; |
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174 } |
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175 |
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176 /** |
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177 * Output the data for a single parameter |
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178 */ |
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179 static err_t str_format_param (char **buf, size_t *buf_size, const char *name, const char *flags, str_format_cb func, void *arg) |
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180 { |
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181 const char *value; |
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182 ssize_t value_len = -1; |
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183 char flag; |
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184 bool use_quote = false; |
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185 err_t err; |
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186 |
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187 // look it up |
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188 if ((err = func(name, &value, &value_len, arg))) |
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189 return err; |
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190 |
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191 // not found? |
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192 if (!value) |
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193 return ERR_STR_FMT_NAME; |
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194 |
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195 // parse flags |
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196 while ((flag = *flags++)) { |
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197 switch (flag) { |
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198 case 'r': |
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199 // quote |
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200 use_quote = true; |
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201 |
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202 break; |
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203 |
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204 default: |
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205 // unknown flag |
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206 return ERR_STR_FMT_FLAG; |
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207 |
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208 } |
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209 } |
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210 |
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211 // output value |
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212 if (use_quote) |
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213 *buf += str_advance(NULL, buf_size, str_quote(*buf, *buf_size, value, value_len)); |
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214 |
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215 else |
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216 *buf += str_advance(NULL, buf_size, str_append_num(*buf, *buf_size, value, value_len)); |
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217 |
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218 // ok |
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219 return SUCCESS; |
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220 } |
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221 |
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222 err_t str_format (char *buf, size_t buf_size, const char *format, str_format_cb func, void *arg) |
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223 { |
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224 char name_buf[STR_FORMAT_PARAM_MAX + 1], *name_ptr; |
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225 size_t name_size; |
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226 char flags_buf[STR_FORMAT_FLAGS_MAX + 1], *flags_ptr; |
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227 size_t flags_size; |
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228 bool in_param = false, in_param_flags = false; |
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229 err_t err; |
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230 |
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231 // iterate over the format string |
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232 do { |
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233 // check buffer state |
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234 if (!buf_size) |
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235 return ERR_STR_FMT_BUF_LEN; |
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236 |
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237 // inspect this char |
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238 switch (*format) { |
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239 case '{': |
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240 // syntax |
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241 if (in_param) |
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242 return ERR_STR_FMT_TAG; |
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243 |
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244 // init state |
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245 in_param = true; |
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246 name_ptr = name_buf; |
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247 name_size = sizeof(name_buf); |
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248 flags_ptr = flags_buf; |
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249 flags_size = sizeof(flags_buf); |
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250 |
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251 *name_ptr = *flags_ptr = '\0'; |
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252 |
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253 break; |
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254 |
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255 case '}': |
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256 // syntax |
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257 if (!in_param) |
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258 return ERR_STR_FMT_TAG; |
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259 |
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260 // reset state |
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261 in_param = false; |
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262 in_param_flags = false; |
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263 |
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264 // output token |
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265 if ((err = str_format_param(&buf, &buf_size, name_buf, flags_buf, func, arg))) |
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266 return err; |
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267 |
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268 break; |
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269 |
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270 case ':': |
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271 if (in_param) { |
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272 // set state |
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273 in_param_flags = true; |
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274 |
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275 break; |
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276 } |
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277 |
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278 /* Fallthrough */ |
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279 |
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280 default: |
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281 if (in_param && in_param_flags ) { |
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282 // add to param flags |
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283 flags_ptr += str_advance(NULL, &flags_size, str_append_char(flags_ptr, flags_size, *format)); |
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284 |
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285 if (!flags_size) |
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286 return ERR_STR_FMT_FLAGS_LEN; |
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287 |
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288 } else if (in_param) { |
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289 // add to param name |
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290 name_ptr += str_advance(NULL, &name_size, str_append_char(name_ptr, name_size, *format)); |
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291 |
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292 if (!name_size) |
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293 return ERR_STR_FMT_NAME_LEN; |
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294 |
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295 } else { |
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296 // add to output |
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297 buf += str_advance(NULL, &buf_size, str_append_char(buf, buf_size, *format)); |
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298 |
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299 } |
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300 |
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301 break; |
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302 } |
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303 } while (*format++); |
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304 |
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305 // syntax |
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306 if (in_param) |
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307 return ERR_STR_FMT_TAG; |
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308 |
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309 // ok |
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310 return SUCCESS; |
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311 } |
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