Get more control over formatting while using libxml2

Question

I have this code (Copied+ a bit minified from here):

#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 tree2 tree2.c
 */

/* A simple example how to create DOM. Libxml2 automagically 
 * allocates the necessary amount of memory to it.
*/
int
main(int argc, char **argv)
{
    xmlDocPtr doc = NULL;       /* document pointer */
    xmlNodePtr root_node = NULL, node = NULL, node1 = NULL;/* node pointers */
    char buff[256];
    int i, j;

    LIBXML_TEST_VERSION;
    doc = xmlNewDoc(BAD_CAST "1.0");
    root_node = xmlNewNode(NULL, BAD_CAST "root");
    xmlDocSetRootElement(doc, root_node);
    xmlCreateIntSubset(doc, BAD_CAST "root", NULL, BAD_CAST "tree2.dtd");
    xmlNewChild(root_node, NULL, BAD_CAST "node1",
                BAD_CAST "content of node 1");
    xmlNewChild(root_node, NULL, BAD_CAST "node2", NULL);
    node =
        xmlNewChild(root_node, NULL, BAD_CAST "node3",
                    BAD_CAST "this node has attributes");
    xmlNewProp(node, BAD_CAST "attribute", BAD_CAST "yes");
    xmlNewProp(node, BAD_CAST "foo", BAD_CAST "bar");
    node = xmlNewNode(NULL, BAD_CAST "node4");
    node1 = xmlNewText(BAD_CAST
                   "other way to create content (which is also a node)");
    xmlAddChild(node, node1);
    xmlAddChild(root_node, node);
    for (i = 5; i < 7; i++) {
        sprintf(buff, "node%d", i);
        node = xmlNewChild(root_node, NULL, BAD_CAST buff, NULL);
        for (j = 1; j < 4; j++) {
            sprintf(buff, "node%d%d", i, j);
            node1 = xmlNewChild(node, NULL, BAD_CAST buff, NULL);
            xmlNewProp(node1, BAD_CAST "odd", BAD_CAST((j % 2) ? "no" : "yes"));
        }
    }
    xmlSaveFormatFileEnc(argc > 1 ? argv[1] : "-", doc, "UTF-8", 1);
    xmlFreeDoc(doc);
    xmlCleanupParser();
    xmlMemoryDump();
    return(0);
}

It gives me the output, but only indented by two spaces, I need to control how many spaces are used or if tabs are used for indenting.

I found this page for saving, but was not able to find any function allowing me to control the indentation.

Answer 1

I found it now:

I have to do e.g.

xmlTreeIndentString = "\t";

to indent with tab or

xmlTreeIndentString = "    ";

to indent with four spaces