This document is simply a very short example illustrating the practical use of XML, and describing the few most important functions provided by the libxml library. This document is based on a tutorial I have found on the DeveloperWorks web site.

Consider the following XML data :

<?xml version="1.0"?>
  <Genealogy>
    <Person name="Vaclav I." dob="After 905" dod="28.9. 929 or 935">tata</Person>
    <Person name="Vratislav I." dob="Unknown" dod="13.2. 921"></Person>
    <Person name="Borivoj I." dob="Unknown" dod="Around 894" />
    <Person name="Ludmila" dob="Unknown" dod="16.9. 921" />
    <Person name="Drahomir" dob="Unknown" dod="Unknown" />
   </Genealogy>

Here is the code to parse the XML file and store its content into a DOM tree. THis code also illustrate the way you can retrieve data from the attributes and content of each node.

#include <gnome-xml/tree.h>
#include <gnome-xml/parser.h>


int main(int argc, char** argv) {
  
  xmlDocPtr doc;
  xmlNodePtr node;
  char *name;
  char *info;
  

  if (argc != 2) {
    printf("Please provide a file name\n");
    exit(0);
  }
  
    doc = xmlParseFile(argv[1]);
  
  if(!doc->root || !doc->root->name || strcasecmp(doc->root->name,"Genealogy")!=0) {
    xmlFreeDoc(doc);
  }
  
    for(node = doc->root->childs; node != NULL; node = node->next) {
  
      name = xmlGetProp(node,"name");
      info = xmlNodeListGetString(doc, node->xmlChildrenNode, 1);

      
      printf("Name=%s", name);
      
      if (info) 
	printf(", info=%s\n", info);
      else
	printf("\n");
      
   
    }
    
  return 0;
}

The command line necessary to compile the above C source code (domxml.c) into an executable binary (domxml) is the following :


cc -o domxml domxml.c -lxml