1  /* Read an XML document from standard input and print an element
       2     outline on standard output.
       3     Must be used with Expat compiled for UTF-8 output.
       4                              __  __            _
       5                           ___\ \/ /_ __   __ _| |_
       6                          / _ \\  /| '_ \ / _` | __|
       7                         |  __//  \| |_) | (_| | |_
       8                          \___/_/\_\ .__/ \__,_|\__|
       9                                   |_| XML parser
      10  
      11     Copyright (c) 2000      Clark Cooper <coopercc@users.sourceforge.net>
      12     Copyright (c) 2001-2003 Fred L. Drake, Jr. <fdrake@users.sourceforge.net>
      13     Copyright (c) 2005-2007 Steven Solie <steven@solie.ca>
      14     Copyright (c) 2005-2006 Karl Waclawek <karl@waclawek.net>
      15     Copyright (c) 2016-2022 Sebastian Pipping <sebastian@pipping.org>
      16     Copyright (c) 2017      Rhodri James <rhodri@wildebeest.org.uk>
      17     Licensed under the MIT license:
      18  
      19     Permission is  hereby granted,  free of charge,  to any  person obtaining
      20     a  copy  of  this  software   and  associated  documentation  files  (the
      21     "Software"),  to  deal in  the  Software  without restriction,  including
      22     without  limitation the  rights  to use,  copy,  modify, merge,  publish,
      23     distribute, sublicense, and/or sell copies of the Software, and to permit
      24     persons  to whom  the Software  is  furnished to  do so,  subject to  the
      25     following conditions:
      26  
      27     The above copyright  notice and this permission notice  shall be included
      28     in all copies or substantial portions of the Software.
      29  
      30     THE  SOFTWARE  IS  PROVIDED  "AS  IS",  WITHOUT  WARRANTY  OF  ANY  KIND,
      31     EXPRESS  OR IMPLIED,  INCLUDING  BUT  NOT LIMITED  TO  THE WARRANTIES  OF
      32     MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN
      33     NO EVENT SHALL THE AUTHORS OR  COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
      34     DAMAGES OR  OTHER LIABILITY, WHETHER  IN AN  ACTION OF CONTRACT,  TORT OR
      35     OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
      36     USE OR OTHER DEALINGS IN THE SOFTWARE.
      37  */
      38  
      39  #include <stdio.h>
      40  #include <expat.h>
      41  
      42  #ifdef XML_LARGE_SIZE
      43  #  define XML_FMT_INT_MOD "ll"
      44  #else
      45  #  define XML_FMT_INT_MOD "l"
      46  #endif
      47  
      48  #ifdef XML_UNICODE_WCHAR_T
      49  #  define XML_FMT_STR "ls"
      50  #else
      51  #  define XML_FMT_STR "s"
      52  #endif
      53  
      54  static void XMLCALL
      55  startElement(void *userData, const XML_Char *name, const XML_Char **atts) {
      56    int i;
      57    int *const depthPtr = (int *)userData;
      58  
      59    for (i = 0; i < *depthPtr; i++)
      60      printf("  ");
      61  
      62    printf("%" XML_FMT_STR, name);
      63  
      64    for (i = 0; atts[i]; i += 2) {
      65      printf(" %" XML_FMT_STR "='%" XML_FMT_STR "'", atts[i], atts[i + 1]);
      66    }
      67  
      68    printf("\n");
      69    *depthPtr += 1;
      70  }
      71  
      72  static void XMLCALL
      73  endElement(void *userData, const XML_Char *name) {
      74    int *const depthPtr = (int *)userData;
      75    (void)name;
      76  
      77    *depthPtr -= 1;
      78  }
      79  
      80  int
      81  main(void) {
      82    XML_Parser parser = XML_ParserCreate(NULL);
      83    int done;
      84    int depth = 0;
      85  
      86    if (! parser) {
      87      fprintf(stderr, "Couldn't allocate memory for parser\n");
      88      return 1;
      89    }
      90  
      91    XML_SetUserData(parser, &depth);
      92    XML_SetElementHandler(parser, startElement, endElement);
      93  
      94    do {
      95      void *const buf = XML_GetBuffer(parser, BUFSIZ);
      96      if (! buf) {
      97        fprintf(stderr, "Couldn't allocate memory for buffer\n");
      98        XML_ParserFree(parser);
      99        return 1;
     100      }
     101  
     102      const size_t len = fread(buf, 1, BUFSIZ, stdin);
     103  
     104      if (ferror(stdin)) {
     105        fprintf(stderr, "Read error\n");
     106        XML_ParserFree(parser);
     107        return 1;
     108      }
     109  
     110      done = feof(stdin);
     111  
     112      if (XML_ParseBuffer(parser, (int)len, done) == XML_STATUS_ERROR) {
     113        fprintf(stderr,
     114                "Parse error at line %" XML_FMT_INT_MOD "u:\n%" XML_FMT_STR "\n",
     115                XML_GetCurrentLineNumber(parser),
     116                XML_ErrorString(XML_GetErrorCode(parser)));
     117        XML_ParserFree(parser);
     118        return 1;
     119      }
     120    } while (! done);
     121  
     122    XML_ParserFree(parser);
     123    return 0;
     124  }