$ rpm -q libxml-devel

$ xml-config --cflags
-I/usr/include/gnome-xml
$ xml-config --libs
-L/usr/lib -lxml -lz

$ cc -Wall `xml-config --cflags`    hello.c  `xml-config --libs` -o hello
$ ./hello hello.xml
'Hello, world!'

<　xml version="1.0"　>

<!-- comment -->

<greeting>Hello, world!</greeting>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <gnome-xml/parser.h>

static int read_xml(const char *fn)
{
  xmlDocPtr doc;
  xmlNodePtr cur;

  doc = xmlParseFile(fn);
  if(doc == NULL) {
    printf("It seems that %s is not a xml data.\n", fn);
    return 1; 
  }

  cur = doc->root;                  
  if (cur == NULL) {                
    printf("empty document\n");
    xmlFreeDoc(doc);              
    return 1;
  }                    

  while( cur ) {
    if( strcmp( cur->name, "greeting")==0 ) {
      printf("'%s'\n",cur->childs->content);
    }
    cur = cur->next;
  }
  xmlFreeDoc(doc);              
  return 0;
}

int main(int argc, char *argv[])
{
  if( argc<2 ) {
    printf("%s xmldata\n",argv[0]);
    return 1;
  }
  return  read_xml(argv[1]);
}

#include <gnome-xml/parser.h>

ファイルからのXML文章読み込み
xmlDocPtr       xmlParseFile            (const char *filename);

構造体の内容の削除
void            xmlFreeDoc              (xmlDocPtr cur);

メモリーからのXML文章読み込み
xmlDocPtr       xmlParseMemory          (char *buffer,int size);

typedef struct _xmlNode xmlNode;
typedef xmlNode *xmlNodePtr;
struct _xmlNode {
    void           *_private;    
    void           *vepv;        

    xmlElementType  type;        
    struct _xmlDoc  *doc;        
    struct _xmlNode *parent;     
    struct _xmlNode *next;       
    struct _xmlNode *prev;       
    struct _xmlNode *childs;     
    struct _xmlNode *last;       
    struct _xmlAttr *properties; 
    const xmlChar  *name;        
    xmlNs          *ns;          
    xmlNs          *nsDef;       
    xmlChar        *content;     
};

typedef enum {
    XML_ELEMENT_NODE=           1,
    XML_ATTRIBUTE_NODE=         2,
    XML_TEXT_NODE=              3,
    XML_CDATA_SECTION_NODE=     4,
    XML_ENTITY_REF_NODE=        5,
    XML_ENTITY_NODE=            6,
    XML_PI_NODE=                7,
    XML_COMMENT_NODE=           8,
    XML_DOCUMENT_NODE=          9,
    XML_DOCUMENT_TYPE_NODE=     10,
    XML_DOCUMENT_FRAG_NODE=     11,
    XML_NOTATION_NODE=          12,
    XML_HTML_DOCUMENT_NODE=     13
} xmlElementType;

$ cc -Wall `xml-config --cflags`    hello2.c  `xml-config --libs` -o hello2
$ ./hello2 hello2.xml
language=English  : Hello!
language=Spanish  : Hola!
language=Japanese : こんにちは!

<　xml version="1.0" encoding="EUC-JP"　>

<greetings>
	<greeting language="English">Hello!</greeting>
	<greeting language="Spanish">Hola!</greeting>
	<greeting language="Japanese">こんにちは!</greeting> 
<greetings>

<!-- encoding="EUC-JP"は、正しくありません。これはあくまでサンプルで
す。latin系の文字と日本語を組み合わせるには、UTF-8を使うべき。ちなみに
, Holaの前には !をひっくり返した文字が必要。
-->

static int read_xml(const char *fn)
{
  xmlDocPtr doc;
  xmlNodePtr cur;
  xmlNodePtr children;

  doc = xmlParseFile(fn);
  if(doc == NULL) {
    printf("It seems that %s is not a xml data.\n", fn);
    return 1; 
  }

  cur = doc->root;                  
  if (cur == NULL) {                
    printf("empty document\n");
    xmlFreeDoc(doc);              
    return 1;
  }                    

  while( cur ) {
    if( strcmp( cur->name, "greetings")==0 ) {
      children = cur->childs;
      while( children ) {
	if( strcmp( children->name, "greeting")==0 ) {
	  printf("language=%-8s : %s\n",
		 xmlGetProp(children,"language"),
		 xmlNodeGetContent(children) );
	}
	children = children->next;
      }
    }
    cur = cur->next;
  }
  xmlFreeDoc(doc);              
  return 0;
}

 #include <gnome-xml/parser.h>

プロパティーの取得
xmlChar *       xmlGetProp              (xmlNodePtr node,
                                         const xmlChar *name);

ノードのコンテンツの取得
xmlChar *       xmlNodeGetContent       (xmlNodePtr cur)  

char* _getprop(xmlNodePtr cur, const char *str)
{
  char *ret=NULL;
  xmlAttrPtr prop = cur->properties;

  while( prop ) {
    if( strcmp( prop->name, str ) == 0 ) {
      ret = prop->val->content;
      break;
    }
    prop = prop->next;
  }

  return ret;
}

typedef struct _xmlAttr xmlAttr;
typedef xmlAttr *xmlAttrPtr;
struct _xmlAttr {
    (一部省略)
    xmlElementType  type;        
    struct _xmlNode *node;       
    struct _xmlAttr *next;       
    const xmlChar   *name;       
    struct _xmlNode *val;        
    xmlNs           *ns;         
};

$ cc -Wall `xml-config --cflags`    xmldir.c  `xml-config --libs` -o xmldir
$ ./xmldir /etc/wu-ftpd/ dir.xml

<　xml version="1.0"　>
<dirent>
  <dir mode="40755">
    <name>/etc/wu-ftpd</name>
    <file mode="40755">ftpaccess</file>
    <file mode="40755">ftpconversions</file>
    <file mode="40755">ftpgroups</file>
    <file mode="40755">ftphosts</file>
    <file mode="40755">ftpusers</file>
  </dir>
</dirent>

/* ------------------------------------------------------------
   This program is free software; you can redistribute it and/or modify
   it under ther terms of GNU General Public License, version 2.

   written by Kazutomo Yoshii <kazutomo@turbolinux.co.jp> 
   ------------------------------------------------------------ */
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/types.h>
#include <dirent.h>
#include <sys/stat.h>
#include <unistd.h>

#include <gnome-xml/parser.h>

static int readdir_to_xml(const char *dirname, xmlNodePtr tree )
{
	DIR *dir;
	struct dirent *ent;
	xmlNodePtr subtree, subsubtree;
	struct stat sbuf;
	char mode_buf[BUFSIZ];

	dir = opendir(dirname);
	if( dir==NULL ) return 0;

	subtree = xmlNewChild(tree, NULL, "dir", NULL);
	xmlNewChild(subtree, NULL, "name", dirname);
	stat(  dirname, &sbuf);
	sprintf(mode_buf, "%o", sbuf.st_mode);
	xmlSetProp(subtree, "mode", mode_buf);

while( (ent=readdir(dir))!=NULL ) {
	if( !(strcmp(ent->d_name,".")==0 ||
		 strcmp(ent->d_name,"..")==0) ) {
		char tmp[BUFSIZ];
		sprintf(tmp, "%s/%s", dirname, ent->d_name);

		 	if( readdir_to_xml(tmp, subtree)==0 ) {
			subsubtree = xmlNewChild(subtree, NULL, "file", ent->d_name );
			stat( ent->d_name, &sbuf);
			sprintf(mode_buf, "%o", sbuf.st_mode);
			xmlSetProp(subsubtree, "mode", mode_buf);
		}
	}
}
	closedir( dir );
	return 1;
}


int main(int argc, char *argv[])
{
	xmlDocPtr doc;
	char dirname[BUFSIZ];

	if( argc < 3 ) {
		printf("%s DIR XMLFILE\n", argv[0]);
		return 1;
	}

	strcpy( dirname, argv[1]);
	/* eliminate the '/' character in the last */   
	if( strlen(dirname)>1 && dirname[strlen(dirname)-1] == (char)'/' ) {
		dirname[strlen(dirname)-1] = (char)NULL;
	}

	doc = xmlNewDoc("1.0");
	doc->root = xmlNewDocNode(doc, NULL, "dirent", NULL);

	if( readdir_to_xml(dirname, doc->root) == 0 ) {
		printf("'%s' is not a directly\n", dirname);
	} else {
		xmlSaveFile(argv[2], doc);
	}
	xmlFreeDoc(doc);
  
	return 0;
}

/* 
 * Local variables:
 *  compile-command: " cc -Wall `gnome-config --cflags xml`
    xmldir.c  `gnome-config --libs xml` -o xmldir"
 *  c-indent-level: 4
 *  c-basic-offset: 4
 *  tab-width: 4
 * End:
 */

#include <gnome-xml/parser.h>

XML文章(の構造)の生成
xmlDocPtr       xmlNewDoc               (const xmlChar *version);

ドキュメントノードの生成
xmlNodePtr      xmlNewDocNode           (xmlDocPtr doc,
                                         xmlNsPtr ns,
                                         const xmlChar *name,
                                         const xmlChar *content);

子ノードの生成
xmlNodePtr      xmlNewChild             (xmlNodePtr parent,
                                         xmlNsPtr ns,
                                         const xmlChar *name,
                                         const xmlChar *content);

プロパティーの設定
xmlAttrPtr      xmlSetProp              (xmlNodePtr node,
                                         const xmlChar *name,
                                         const xmlChar *value);

XML文章(の構造)をファイルへ保存
int             xmlSaveFile             (const char *filename,
                                         xmlDocPtr cur);