added Dodji's example, added output handling Daniel

* doc/examples/*: added Dodji's example, added output handling
Daniel

doc/examples/tree1.c

@@ -0,0 +1,86 @@
+/**
+ * section: Tree
+ * synopsis: Navigates a tree to print element names
+ * purpose: Parse a file to a tree, use xmlDocGetRootElement() to
+ *          get the root element, then walk the document and print
+ *          all the element name in document order.
+ * usage: tree1 filename_or_URL
+ * test: tree1 test2.xml > tree1.tmp ; diff tree1.tmp tree1.out ; rm tree1.tmp
+ * author: Dodji Seketeli
+ * copy: see Copyright for the status of this software.
+ */
+#include <stdio.h>
+#include <libxml/parser.h>
+#include <libxml/tree.h>
+
+/*
+ *To compile this file using gcc you can type
+ *gcc `xml2-config --cflags --libs` -o xmlexample libxml2-example.c
+ */
+
+/**
+ * print_element_names:
+ * @a_node: the initial xml node to consider.
+ *
+ * Prints the names of the all the xml elements
+ * that are siblings or children of a given xml node.
+ */
+void
+print_element_names(xmlNode * a_node)
+{
+    xmlNode *cur_node = NULL;
+
+    for (cur_node = a_node; cur_node; cur_node = cur_node->next) {
+        if (cur_node->type == XML_ELEMENT_NODE) {
+            printf("node type: Element, name: %s\n", cur_node->name);
+        }
+
+        print_element_names(cur_node->children);
+    }
+}
+
+
+/**
+ * Simple example to parse a file called "file.xml", 
+ * walk down the DOM, and print the name of the 
+ * xml elements nodes.
+ */
+int
+main(int argc, char **argv)
+{
+    xmlDoc *doc = NULL;
+    xmlNode *root_element = NULL;
+
+    if (argc != 2)
+        return(1);
+
+    /*
+     * this initialize the library and check potential ABI mismatches
+     * between the version it was compiled for and the actual shared
+     * library used.
+     */
+    LIBXML_TEST_VERSION
+
+    /*parse the file and get the DOM */
+    doc = xmlParseFile(argv[1]);
+
+    if (doc == NULL) {
+        printf("error: could not parse file file.xml\n");
+    }
+
+    /*Get the root element node */
+    root_element = xmlDocGetRootElement(doc);
+
+    print_element_names(root_element);
+
+    /*free the document */
+    xmlFreeDoc(doc);
+
+    /*
+     *Free the global variables that may
+     *have been allocated by the parser.
+     */
+    xmlCleanupParser();
+
+    return 0;
+}