1  /* This is simple demonstration of how to use expat. This program
       2     reads an XML document from standard input and writes a line with
       3     the name of each element to standard output indenting child
       4     elements by one tab stop more than their parent element.
       5     It must be used with Expat compiled for UTF-8 output.
       6                              __  __            _
       7                           ___\ \/ /_ __   __ _| |_
       8                          / _ \\  /| '_ \ / _` | __|
       9                         |  __//  \| |_) | (_| | |_
      10                          \___/_/\_\ .__/ \__,_|\__|
      11                                   |_| XML parser
      12  
      13     Copyright (c) 1997-2000 Thai Open Source Software Center Ltd
      14     Copyright (c) 2001-2003 Fred L. Drake, Jr. <fdrake@users.sourceforge.net>
      15     Copyright (c) 2004-2006 Karl Waclawek <karl@waclawek.net>
      16     Copyright (c) 2005-2007 Steven Solie <steven@solie.ca>
      17     Copyright (c) 2016-2022 Sebastian Pipping <sebastian@pipping.org>
      18     Copyright (c) 2017      Rhodri James <rhodri@wildebeest.org.uk>
      19     Copyright (c) 2019      Zhongyuan Zhou <zhouzhongyuan@huawei.com>
      20     Licensed under the MIT license:
      21  
      22     Permission is  hereby granted,  free of charge,  to any  person obtaining
      23     a  copy  of  this  software   and  associated  documentation  files  (the
      24     "Software"),  to  deal in  the  Software  without restriction,  including
      25     without  limitation the  rights  to use,  copy,  modify, merge,  publish,
      26     distribute, sublicense, and/or sell copies of the Software, and to permit
      27     persons  to whom  the Software  is  furnished to  do so,  subject to  the
      28     following conditions:
      29  
      30     The above copyright  notice and this permission notice  shall be included
      31     in all copies or substantial portions of the Software.
      32  
      33     THE  SOFTWARE  IS  PROVIDED  "AS  IS",  WITHOUT  WARRANTY  OF  ANY  KIND,
      34     EXPRESS  OR IMPLIED,  INCLUDING  BUT  NOT LIMITED  TO  THE WARRANTIES  OF
      35     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
      36     NO EVENT SHALL THE AUTHORS OR  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
      37     DAMAGES OR  OTHER LIABILITY, WHETHER  IN AN  ACTION OF CONTRACT,  TORT OR
      38     OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
      39     USE OR OTHER DEALINGS IN THE SOFTWARE.
      40  */
      41  
      42  #include <stdio.h>
      43  #include <expat.h>
      44  
      45  #ifdef XML_LARGE_SIZE
      46  #  define XML_FMT_INT_MOD "ll"
      47  #else
      48  #  define XML_FMT_INT_MOD "l"
      49  #endif
      50  
      51  #ifdef XML_UNICODE_WCHAR_T
      52  #  define XML_FMT_STR "ls"
      53  #else
      54  #  define XML_FMT_STR "s"
      55  #endif
      56  
      57  static void XMLCALL
      58  startElement(void *userData, const XML_Char *name, const XML_Char **atts) {
      59    int i;
      60    int *const depthPtr = (int *)userData;
      61    (void)atts;
      62  
      63    for (i = 0; i < *depthPtr; i++)
      64      putchar('\t');
      65    printf("%" XML_FMT_STR "\n", name);
      66    *depthPtr += 1;
      67  }
      68  
      69  static void XMLCALL
      70  endElement(void *userData, const XML_Char *name) {
      71    int *const depthPtr = (int *)userData;
      72    (void)name;
      73  
      74    *depthPtr -= 1;
      75  }
      76  
      77  int
      78  main(void) {
      79    XML_Parser parser = XML_ParserCreate(NULL);
      80    int done;
      81    int depth = 0;
      82  
      83    if (! parser) {
      84      fprintf(stderr, "Couldn't allocate memory for parser\n");
      85      return 1;
      86    }
      87  
      88    XML_SetUserData(parser, &depth);
      89    XML_SetElementHandler(parser, startElement, endElement);
      90  
      91    do {
      92      void *const buf = XML_GetBuffer(parser, BUFSIZ);
      93      if (! buf) {
      94        fprintf(stderr, "Couldn't allocate memory for buffer\n");
      95        XML_ParserFree(parser);
      96        return 1;
      97      }
      98  
      99      const size_t len = fread(buf, 1, BUFSIZ, stdin);
     100  
     101      if (ferror(stdin)) {
     102        fprintf(stderr, "Read error\n");
     103        XML_ParserFree(parser);
     104        return 1;
     105      }
     106  
     107      done = feof(stdin);
     108  
     109      if (XML_ParseBuffer(parser, (int)len, done) == XML_STATUS_ERROR) {
     110        fprintf(stderr,
     111                "Parse error at line %" XML_FMT_INT_MOD "u:\n%" XML_FMT_STR "\n",
     112                XML_GetCurrentLineNumber(parser),
     113                XML_ErrorString(XML_GetErrorCode(parser)));
     114        XML_ParserFree(parser);
     115        return 1;
     116      }
     117    } while (! done);
     118  
     119    XML_ParserFree(parser);
     120    return 0;
     121  }