test.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <libxml/parser.h>

void examine_nodes(char * xml) {
  xmlDocPtr doc = xmlReadMemory(xml, strlen(xml), NULL, NULL,
      XML_PARSE_NOBLANKS);

  xmlNodePtr bbb_node = xmlDocGetRootElement(doc)->children;

  xmlNodePtr child = bbb_node->children;
  while(child) {
    printf("%s: blank? %d\n", child->name, xmlIsBlankNode(child));
    child = child->next;
  }
}

int main(int argc, char *argv[]) {
  char *xml_no_text = "<?xml version='1.0' encoding='UTF-8'?>" \
                   "<aaa><bbb> <ccc /> <ccc /> </bbb></aaa>";

  char *xml_text = "<?xml version='1.0' encoding='UTF-8'?>" \
                   "<aaa><bbb>hello world <ccc /> <ccc /> </bbb></aaa>";

  examine_nodes(xml_no_text);
  printf("##############\n");
  examine_nodes(xml_text);
  return 0;
}