1 /***************************************************************************
3 * Project ___| | | | _ \| |
5 * | (__| |_| | _ <| |___
6 * \___|\___/|_| \_\_____|
8 * Copyright (C) 1998 - 2011, Daniel Stenberg, <daniel@haxx.se>, et al.
10 * This software is licensed as described in the file COPYING, which
11 * you should have received as part of this distribution. The terms
12 * are also available at http://curl.haxx.se/docs/copyright.html.
14 * You may opt to use, copy, modify, merge, publish, distribute and/or sell
15 * copies of the Software, and permit persons to whom the Software is
16 * furnished to do so, under the terms of the COPYING file.
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
21 ***************************************************************************/
22 // Get a web page, parse it with libxml.
24 // Written by Lars Nilsson
26 // GNU C++ compile command line suggestion (edit paths accordingly):
28 // g++ -Wall -I/opt/curl/include -I/opt/libxml/include/libxml2 htmltitle.cpp \
29 // -o htmltitle -L/opt/curl/lib -L/opt/libxml/lib -lcurl -lxml2
35 #include <curl/curl.h>
36 #include <libxml/HTMLparser.h>
39 // Case-insensitive string comparison
43 #define COMPARE(a, b) (!stricmp((a), (b)))
45 #define COMPARE(a, b) (!strcasecmp((a), (b)))
49 // libxml callback context structure
54 Context(): addTitle(false) { }
61 // libcurl variables for error strings and returned data
63 static char errorBuffer[CURL_ERROR_SIZE];
64 static std::string buffer;
67 // libcurl write callback function
70 static int writer(char *data, size_t size, size_t nmemb,
71 std::string *writerData)
73 if (writerData == NULL)
76 writerData->append(data, size*nmemb);
82 // libcurl connection initialization
85 static bool init(CURL *&conn, char *url)
89 conn = curl_easy_init();
93 fprintf(stderr, "Failed to create CURL connection\n");
98 code = curl_easy_setopt(conn, CURLOPT_ERRORBUFFER, errorBuffer);
101 fprintf(stderr, "Failed to set error buffer [%d]\n", code);
106 code = curl_easy_setopt(conn, CURLOPT_URL, url);
107 if (code != CURLE_OK)
109 fprintf(stderr, "Failed to set URL [%s]\n", errorBuffer);
114 code = curl_easy_setopt(conn, CURLOPT_FOLLOWLOCATION, 1L);
115 if (code != CURLE_OK)
117 fprintf(stderr, "Failed to set redirect option [%s]\n", errorBuffer);
122 code = curl_easy_setopt(conn, CURLOPT_WRITEFUNCTION, writer);
123 if (code != CURLE_OK)
125 fprintf(stderr, "Failed to set writer [%s]\n", errorBuffer);
130 code = curl_easy_setopt(conn, CURLOPT_WRITEDATA, &buffer);
131 if (code != CURLE_OK)
133 fprintf(stderr, "Failed to set write data [%s]\n", errorBuffer);
142 // libxml start element callback function
145 static void StartElement(void *voidContext,
147 const xmlChar **attributes)
149 Context *context = (Context *)voidContext;
151 if (COMPARE((char *)name, "TITLE"))
154 context->addTitle = true;
160 // libxml end element callback function
163 static void EndElement(void *voidContext,
166 Context *context = (Context *)voidContext;
168 if (COMPARE((char *)name, "TITLE"))
169 context->addTitle = false;
173 // Text handling helper function
176 static void handleCharacters(Context *context,
177 const xmlChar *chars,
180 if (context->addTitle)
181 context->title.append((char *)chars, length);
185 // libxml PCDATA callback function
188 static void Characters(void *voidContext,
189 const xmlChar *chars,
192 Context *context = (Context *)voidContext;
194 handleCharacters(context, chars, length);
198 // libxml CDATA callback function
201 static void cdata(void *voidContext,
202 const xmlChar *chars,
205 Context *context = (Context *)voidContext;
207 handleCharacters(context, chars, length);
211 // libxml SAX callback structure
214 static htmlSAXHandler saxHandler =
246 // Parse given (assumed to be) HTML text and return the title
249 static void parseHtml(const std::string &html,
252 htmlParserCtxtPtr ctxt;
255 ctxt = htmlCreatePushParserCtxt(&saxHandler, &context, "", 0, "",
256 XML_CHAR_ENCODING_NONE);
258 htmlParseChunk(ctxt, html.c_str(), html.size(), 0);
259 htmlParseChunk(ctxt, "", 0, 1);
261 htmlFreeParserCtxt(ctxt);
263 title = context.title;
266 int main(int argc, char *argv[])
272 // Ensure one argument is given
276 fprintf(stderr, "Usage: %s <url>\n", argv[0]);
281 curl_global_init(CURL_GLOBAL_DEFAULT);
283 // Initialize CURL connection
285 if (!init(conn, argv[1]))
287 fprintf(stderr, "Connection initializion failed\n");
292 // Retrieve content for the URL
294 code = curl_easy_perform(conn);
295 curl_easy_cleanup(conn);
297 if (code != CURLE_OK)
299 fprintf(stderr, "Failed to get '%s' [%s]\n", argv[1], errorBuffer);
304 // Parse the (assumed) HTML code
306 parseHtml(buffer, title);
308 // Display the extracted title
310 printf("Title: %s\n", title.c_str());