#include <stdio.h>
#include <string.h>
#include <libxml/xmlreader.h>

void main ()
{
    char *s = "<elem att1='foo' att2='bar'/>";

    xmlTextReaderPtr xml = xmlReaderForMemory (s, strlen(s), NULL, NULL, 0);

    while (xmlTextReaderRead (xml) == 1)
        while (xmlTextReaderMoveToNextAttribute (xml) == 1)
            while (xmlTextReaderReadAttributeValue (xml) == 1)
                printf ("%s\n", xmlTextReaderValue (xml));
}

/* Compile with gcc -o attributevalue attributevalue.c `pkg-config --cflags --libs libxml-2.0` */