HTML-XML-utils由一套小型C程序（过滤器）组成

				/*				 * Routines to check for the occurrence of a class.				 *				 * Author: Bert Bos 				 * Created: 20 Aug 2000				 * Version: $Id: class.c,v 1.1 2000/08/20 16:31:52 bbos Exp $				 *				 **/								#include "config.h"				#include 				#if STDC_HEADERS				# include 				#else				# ifndef HAVE_STRCHR				#  define strchr index				#  define strrchr rindex				# endif				# ifndef HAVE_STRSTR				#  include "strstr.e"				# endif				#endif				#include 				#include "export.h"				#include "types.e"												/* contains -- check if string contains a certain word, return pointer */				EXPORT const string contains(const string s, const string word)				{				  string t = s;				  unsigned char c;								  while ((t = strstr(t, word))) {				    if ((c = *(t + strlen(word))) && !isspace(c)) t++; /* Not end of word */				    else if (t != s && !isspace(*(t - 1))) t++;	/* Not beginning of word */				    else return t;				/* Found it */				  }				  return NULL;					/* Not found */				}								/* has_class -- check for class=word in list of attributes */				EXPORT Boolean has_class(pairlist attribs, const string word)				{				  pairlist p;								  for (p = attribs; p; p = p->next) {				    if (strcasecmp(p->name, "class") == 0 && contains(p->value, word))				      return True;				  }				  return False;				}