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// Copyright 2013 Google Inc. All Rights Reserved.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
// Author: jdtang@google.com (Jonathan Tang)
//
// Retrieves the title of a page.
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/stat.h>
#include "gumbo.h"
static void read_file(FILE* fp, char** output, int* length) {
struct stat filestats;
int fd = fileno(fp);
fstat(fd, &filestats);
*length = filestats.st_size;
*output = malloc(*length + 1);
int start = 0;
int bytes_read;
while ((bytes_read = fread(*output + start, 1, *length - start, fp))) {
start += bytes_read;
}
}
static const char* find_title(const GumboNode* root) {
assert(root->type == GUMBO_NODE_ELEMENT);
assert(root->v.element.children.length >= 2);
const GumboVector* root_children = &root->v.element.children;
GumboNode* head = NULL;
for (int i = 0; i < root_children->length; ++i) {
GumboNode* child = root_children->data[i];
if (child->type == GUMBO_NODE_ELEMENT &&
child->v.element.tag == GUMBO_TAG_HEAD) {
head = child;
break;
}
}
assert(head != NULL);
GumboVector* head_children = &head->v.element.children;
for (int i = 0; i < head_children->length; ++i) {
GumboNode* child = head_children->data[i];
if (child->type == GUMBO_NODE_ELEMENT &&
child->v.element.tag == GUMBO_TAG_TITLE) {
if (child->v.element.children.length != 1) {
return "<empty title>";
}
GumboNode* title_text = child->v.element.children.data[0];
assert(title_text->type == GUMBO_NODE_TEXT || title_text->type == GUMBO_NODE_WHITESPACE);
return title_text->v.text.text;
}
}
return "<no title found>";
}
int main(int argc, const char** argv) {
if (argc != 2) {
printf("Usage: get_title <html filename>.\n");
exit(EXIT_FAILURE);
}
const char* filename = argv[1];
FILE* fp = fopen(filename, "r");
if (!fp) {
printf("File %s not found!\n", filename);
exit(EXIT_FAILURE);
}
char* input;
int input_length;
read_file(fp, &input, &input_length);
GumboOutput* output = gumbo_parse_with_options(
&kGumboDefaultOptions, input, input_length);
const char* title = find_title(output->root);
printf("%s\n", title);
gumbo_destroy_output(&kGumboDefaultOptions, output);
free(input);
}
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