| 1 | /* |
| 2 | * This file is part of DisOrder |
| 3 | * Copyright (C) 2007 Richard Kettlewell |
| 4 | * |
| 5 | * This program is free software; you can redistribute it and/or modify |
| 6 | * it under the terms of the GNU General Public License as published by |
| 7 | * the Free Software Foundation; either version 2 of the License, or |
| 8 | * (at your option) any later version. |
| 9 | * |
| 10 | * This program is distributed in the hope that it will be useful, but |
| 11 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 13 | * General Public License for more details. |
| 14 | * |
| 15 | * You should have received a copy of the GNU General Public License |
| 16 | * along with this program; if not, write to the Free Software |
| 17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| 18 | * USA |
| 19 | */ |
| 20 | /** @file lib/html.c |
| 21 | * @brief Noddy HTML parser |
| 22 | */ |
| 23 | |
| 24 | #include <config.h> |
| 25 | #include "types.h" |
| 26 | |
| 27 | #include <string.h> |
| 28 | #include <ctype.h> |
| 29 | #include <stddef.h> |
| 30 | |
| 31 | #include "hash.h" |
| 32 | #include "html.h" |
| 33 | #include "mem.h" |
| 34 | #include "log.h" |
| 35 | #include "vector.h" |
| 36 | #include "charset.h" |
| 37 | #include "table.h" |
| 38 | |
| 39 | /** @brief Entity table type */ |
| 40 | struct entity { |
| 41 | const char *name; |
| 42 | uint32_t value; |
| 43 | }; |
| 44 | |
| 45 | /** @brief Known entities |
| 46 | * |
| 47 | * We only support the entities that turn up in the HTML files we |
| 48 | * actually care about. |
| 49 | * |
| 50 | * Keep in alphabetical order. |
| 51 | */ |
| 52 | static const struct entity entities[] = { |
| 53 | { "amp", '&' }, |
| 54 | { "gt", '>' }, |
| 55 | { "lt", '<' } |
| 56 | }; |
| 57 | |
| 58 | /** @brief Skip whitespace */ |
| 59 | static const char *skipwhite(const char *input) { |
| 60 | while(*input && isspace((unsigned char)*input)) |
| 61 | ++input; |
| 62 | return input; |
| 63 | } |
| 64 | |
| 65 | /** @brief Parse an entity */ |
| 66 | static const char *parse_entity(const char *input, |
| 67 | uint32_t *entityp) { |
| 68 | input = skipwhite(input); |
| 69 | if(*input == '#') { |
| 70 | input = skipwhite(input + 1); |
| 71 | if(*input == 'x') |
| 72 | *entityp = strtoul(skipwhite(input + 1), (char **)&input, 16); |
| 73 | else |
| 74 | *entityp = strtoul(input, (char **)&input, 10); |
| 75 | } else { |
| 76 | struct dynstr name[1]; |
| 77 | int n; |
| 78 | |
| 79 | dynstr_init(name); |
| 80 | while(isalnum((unsigned char)*input)) |
| 81 | dynstr_append(name, tolower((unsigned char)*input++)); |
| 82 | dynstr_terminate(name); |
| 83 | if((n = TABLE_FIND(entities, struct entity, name, name->vec)) < 0) { |
| 84 | error(0, "unknown entity '%s'", name->vec); |
| 85 | *entityp = '?'; |
| 86 | } else |
| 87 | *entityp = entities[n].value; |
| 88 | } |
| 89 | input = skipwhite(input); |
| 90 | if(*input == ';') |
| 91 | ++input; |
| 92 | return input; |
| 93 | } |
| 94 | |
| 95 | /** @brief Parse one character or entity and append it to a @ref dynstr */ |
| 96 | static const char *parse_one(const char *input, struct dynstr *d) { |
| 97 | if(*input == '&') { |
| 98 | uint32_t c; |
| 99 | input = parse_entity(input + 1, &c); |
| 100 | if(one_ucs42utf8(c, d)) |
| 101 | dynstr_append(d, '?'); /* U+FFFD might be a better choice */ |
| 102 | } else |
| 103 | dynstr_append(d, *input++); |
| 104 | return input; |
| 105 | } |
| 106 | |
| 107 | /** @brief Too-stupid-to-live HTML parser |
| 108 | * @param callbacks Parser callbacks |
| 109 | * @param input HTML document |
| 110 | * @param u User data pointer |
| 111 | * @return 0 on success, -1 on error |
| 112 | */ |
| 113 | int html_parse(const struct html_parser_callbacks *callbacks, |
| 114 | const char *input, |
| 115 | void *u) { |
| 116 | struct dynstr text[1]; |
| 117 | |
| 118 | dynstr_init(text); |
| 119 | while(*input) { |
| 120 | if(*input == '<') { |
| 121 | struct dynstr tag[1]; |
| 122 | hash *attrs; |
| 123 | |
| 124 | /* flush collected text */ |
| 125 | if(text->nvec) { |
| 126 | dynstr_terminate(text); |
| 127 | callbacks->text(text->vec, u); |
| 128 | text->nvec = 0; |
| 129 | } |
| 130 | dynstr_init(tag); |
| 131 | input = skipwhite(input + 1); |
| 132 | /* see if it's an open or close tag */ |
| 133 | if(*input == '/') { |
| 134 | input = skipwhite(input + 1); |
| 135 | attrs = 0; |
| 136 | } else |
| 137 | attrs = hash_new(sizeof(char *)); |
| 138 | /* gather tag */ |
| 139 | while(isalnum((unsigned char)*input)) |
| 140 | dynstr_append(tag, tolower((unsigned char)*input++)); |
| 141 | dynstr_terminate(tag); |
| 142 | input = skipwhite(input); |
| 143 | if(attrs) { |
| 144 | /* gather attributes */ |
| 145 | while(*input && *input != '>') { |
| 146 | struct dynstr name[1], value[1]; |
| 147 | |
| 148 | dynstr_init(name); |
| 149 | dynstr_init(value); |
| 150 | /* attribute name */ |
| 151 | while(isalnum((unsigned char)*input)) |
| 152 | dynstr_append(name, tolower((unsigned char)*input++)); |
| 153 | dynstr_terminate(name); |
| 154 | input = skipwhite(input); |
| 155 | if(*input == '=') { |
| 156 | /* attribute value */ |
| 157 | input = skipwhite(input + 1); |
| 158 | if(*input == '"' || *input == '\'') { |
| 159 | /* quoted value */ |
| 160 | const int q = *input++; |
| 161 | while(*input && *input != q) |
| 162 | input = parse_one(input, value); |
| 163 | if(*input == q) |
| 164 | ++input; |
| 165 | } else { |
| 166 | /* unquoted value */ |
| 167 | while(*input && *input != '>' && !isspace((unsigned char)*input)) |
| 168 | input = parse_one(input, value); |
| 169 | } |
| 170 | dynstr_terminate(value); |
| 171 | } |
| 172 | /* stash the value */ |
| 173 | hash_add(attrs, name->vec, value->vec, HASH_INSERT_OR_REPLACE); |
| 174 | input = skipwhite(input); |
| 175 | } |
| 176 | } |
| 177 | if(*input != '>') { |
| 178 | error(0, "unterminated tag %s", tag->vec); |
| 179 | return -1; |
| 180 | } |
| 181 | ++input; |
| 182 | if(attrs) |
| 183 | callbacks->open(tag->vec, attrs, u); |
| 184 | else |
| 185 | callbacks->close(tag->vec, u); |
| 186 | } else |
| 187 | input = parse_one(input, text); |
| 188 | } |
| 189 | /* flush any trailing text */ |
| 190 | if(text->nvec) { |
| 191 | dynstr_terminate(text); |
| 192 | callbacks->text(text->vec, u); |
| 193 | text->nvec = 0; |
| 194 | } |
| 195 | return 0; |
| 196 | } |
| 197 | |
| 198 | /* |
| 199 | Local Variables: |
| 200 | c-basic-offset:2 |
| 201 | comment-column:40 |
| 202 | fill-column:79 |
| 203 | indent-tabs-mode:nil |
| 204 | End: |
| 205 | */ |