xref: /third_party/curl/docs/examples/htmltidy.c (revision 13498266)
1/***************************************************************************
2 *                                  _   _ ____  _
3 *  Project                     ___| | | |  _ \| |
4 *                             / __| | | | |_) | |
5 *                            | (__| |_| |  _ <| |___
6 *                             \___|\___/|_| \_\_____|
7 *
8 * Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
9 *
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 https://curl.se/docs/copyright.html.
13 *
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.
17 *
18 * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
19 * KIND, either express or implied.
20 *
21 * SPDX-License-Identifier: curl
22 *
23 ***************************************************************************/
24/* <DESC>
25 * Download a document and use libtidy to parse the HTML.
26 * </DESC>
27 */
28/*
29 * LibTidy => https://www.html-tidy.org/
30 */
31
32#include <stdio.h>
33#include <tidy/tidy.h>
34#include <tidy/tidybuffio.h>
35#include <curl/curl.h>
36
37/* curl write callback, to fill tidy's input buffer...  */
38uint write_cb(char *in, uint size, uint nmemb, TidyBuffer *out)
39{
40  uint r;
41  r = size * nmemb;
42  tidyBufAppend(out, in, r);
43  return r;
44}
45
46/* Traverse the document tree */
47void dumpNode(TidyDoc doc, TidyNode tnod, int indent)
48{
49  TidyNode child;
50  for(child = tidyGetChild(tnod); child; child = tidyGetNext(child) ) {
51    ctmbstr name = tidyNodeGetName(child);
52    if(name) {
53      /* if it has a name, then it's an HTML tag ... */
54      TidyAttr attr;
55      printf("%*.*s%s ", indent, indent, "<", name);
56      /* walk the attribute list */
57      for(attr = tidyAttrFirst(child); attr; attr = tidyAttrNext(attr) ) {
58        printf("%s", tidyAttrName(attr));
59        tidyAttrValue(attr)?printf("=\"%s\" ",
60                                   tidyAttrValue(attr)):printf(" ");
61      }
62      printf(">\n");
63    }
64    else {
65      /* if it does not have a name, then it's probably text, cdata, etc... */
66      TidyBuffer buf;
67      tidyBufInit(&buf);
68      tidyNodeGetText(doc, child, &buf);
69      printf("%*.*s\n", indent, indent, buf.bp?(char *)buf.bp:"");
70      tidyBufFree(&buf);
71    }
72    dumpNode(doc, child, indent + 4); /* recursive */
73  }
74}
75
76
77int main(int argc, char **argv)
78{
79  if(argc == 2) {
80    CURL *curl;
81    char curl_errbuf[CURL_ERROR_SIZE];
82    TidyDoc tdoc;
83    TidyBuffer docbuf = {0};
84    TidyBuffer tidy_errbuf = {0};
85    int err;
86
87    curl = curl_easy_init();
88    curl_easy_setopt(curl, CURLOPT_URL, argv[1]);
89    curl_easy_setopt(curl, CURLOPT_ERRORBUFFER, curl_errbuf);
90    curl_easy_setopt(curl, CURLOPT_NOPROGRESS, 0L);
91    curl_easy_setopt(curl, CURLOPT_VERBOSE, 1L);
92    curl_easy_setopt(curl, CURLOPT_WRITEFUNCTION, write_cb);
93
94    tdoc = tidyCreate();
95    tidyOptSetBool(tdoc, TidyForceOutput, yes); /* try harder */
96    tidyOptSetInt(tdoc, TidyWrapLen, 4096);
97    tidySetErrorBuffer(tdoc, &tidy_errbuf);
98    tidyBufInit(&docbuf);
99
100    curl_easy_setopt(curl, CURLOPT_WRITEDATA, &docbuf);
101    err = curl_easy_perform(curl);
102    if(!err) {
103      err = tidyParseBuffer(tdoc, &docbuf); /* parse the input */
104      if(err >= 0) {
105        err = tidyCleanAndRepair(tdoc); /* fix any problems */
106        if(err >= 0) {
107          err = tidyRunDiagnostics(tdoc); /* load tidy error buffer */
108          if(err >= 0) {
109            dumpNode(tdoc, tidyGetRoot(tdoc), 0); /* walk the tree */
110            fprintf(stderr, "%s\n", tidy_errbuf.bp); /* show errors */
111          }
112        }
113      }
114    }
115    else
116      fprintf(stderr, "%s\n", curl_errbuf);
117
118    /* clean-up */
119    curl_easy_cleanup(curl);
120    tidyBufFree(&docbuf);
121    tidyBufFree(&tidy_errbuf);
122    tidyRelease(tdoc);
123    return err;
124
125  }
126  else
127    printf("usage: %s <url>\n", argv[0]);
128
129  return 0;
130}
131