require "page.class.php";
$neirong = "内容内容内容内容内容内容内容内容内容内容内容内容内容内容";
$content = file_get_contents($neirong); 
$ipage = isset($_GET["ipage"]) ? intval($_GET["ipage"]) : 1; 
$CP = new cutpage($content); 
$page = $CP->cut_str(); 
echo $page[$ipage - 1]; 
echo '' . $CP->pagenav() . '';
class类
page.class.php
/*  
*  长文章分页类     
*/  
    class cutpage{    
        private $pagestr;       //被切分的内容    
        private $pagearr;       //被切分文字的数组格式    
        private $sum_word;      //总字数(UTF-8格式的中文字符也包括)    
        private $sum_page;      //总页数    
        private $page_word;     //一页多少字    
        private $cut_tag;       //自动分页符    
        private $cut_custom;    //手动分页符    
        private $ipage;         //当前切分的页数,第几页    
        private $url;    
         
        function __construct($pagestr,$page_word=1000){    
            $this->page_word = $page_word;    
            $this->cut_tag = array("", "", "
", "
", "”。", "。", ".", "!", "……", "?", ",");    
            $this->cut_custom = "{nextpage}";    
            $tmp_page = isset($_GET["ipage"]) ? intval($_GET["ipage"]) : 1;    
            $this->ipage = $tmp_page>1?$tmp_page:1; 
            $this->pagestr = $pagestr;
        }    
        //统计总字数    
        function get_page_word(){    
            $this->sum_word = $this->strlen_utf8($this->pagestr);    
            return $this->sum_word;    
        }    
        /*  统计UTF-8编码的字符长度  
         *  一个中文,一个英文都为一个字  
         */  
        function strlen_utf8($str){    
           $i = 0;    
           $count = 0;    
           $len = strlen ($str);    
           while ($i 
               $chr = ord ($str[$i]);    
               $count++;    
               $i++;    
               if ($i >= $len)    
                   break;    
               if ($chr & 0x80){    
                   $chr 
                   while ($chr & 0x80) {    
                       $i++;    
                       $chr 
                   }    
               }    
           }    
           return $count;    
        }    
        //设置自动分页符号    
        function set_cut_tag($tag_arr=array()){    
            $this->cut_tag = $tag_arr;    
        }    
        //设置手动分页符    
        function set_cut_custom($cut_str){    
            $this->cut_custom = $cut_str;    
        }    
        function show_cpage($ipage=0){    
            $this->cut_str();    
            $ipage = $ipage ? $ipage:$this->ipage;    
            return $this->pagearr[$ipage];    
        }    
        function cut_str(){    
            $str_len_word = strlen($this->pagestr);     //获取使用strlen得到的字符总数    
            $i = 0;    
            if ($str_len_wordpage_word){   //如果总字数小于一页显示字数    
                $page_arr[$i] = $this->pagestr;    
            }else{    
                if (strpos($this->pagestr, $this->cut_custom)){    
                    $page_arr = 
explode($this->cut_custom, $this->pagestr);    
                }else{    
                    $str_first = 
substr($this->pagestr, 0, $this->page_word);   //0-page_word个文字    cutStr为func.global中的函数    
                    
foreach ($this->cut_tag as $v){    
                        $cut_start = strrpos($str_first, $v);       //逆向查找第一个分页符的位置    
                        if ($cut_start){    
                            $page_arr[$i++] = substr($this->pagestr, 0, $cut_start).$v;    
                            $cut_start = $cut_start + strlen($v);    
                            break;    
                        }    
                    }    
                    if (($cut_start+$this->page_word)>=$str_len_word){  //如果超过总字数    
                        $page_arr[$i++] = substr($this->pagestr, $cut_start, $this->page_word);    
                    }else{    
                        while (($cut_start+$this->page_word)
                            foreach ($this->cut_tag as $v){    
                                $str_tmp = substr($this->pagestr, $cut_start, $this->page_word);        //取第cut_start个字后的page_word个字符    
                                $cut_tmp = strrpos($str_tmp, $v);       //找出从第cut_start个字之后,page_word个字之间,逆向查找第一个分页符的位置    
                                if ($cut_tmp){    
                                    $page_arr[$i++] = substr($str_tmp, 0, $cut_tmp).$v;    
                                    $cut_start = $cut_start + $cut_tmp + strlen($v);    
                                    break;    
                                }    
                            }      
                        }    
                        if (($cut_start+$this->page_word)>$str_len_word){    
                            $page_arr[$i++] = substr($this->pagestr, $cut_start, $this->page_word);    
                        }    
                    }    
                }    
            }    
            $this->sum_page = count($page_arr);     //总页数    
            $this->pagearr = $page_arr;  
            return $page_arr;
        }    
        //显示上一条,下一条    
        function pagenav(){    
            $this->set_url();    
            $str = '';
             
            //$str .= $this->ipage.'/'.$this->sum_page;
             
            for($i=1;$isum_page;$i++){
                if($i==$this->ipage) {
                    $str.= " ";
                }else{
                    $str.= " ";
                }
            }
             
                  
            return $str;    
        }    
        function show_prv_next2(){    
            $this->set_url();    
            $str = '';
             
             
             
            if ($this->sum_page>1 and $this->ipage>1){    
                $str.= " ";    
            }   
            if ($this->sum_page>1 and $this->ipagesum_page){    
                $str .= "";    
            }           
            return $str;    
        }    
        function show_page_
select(){    
            if ($this->sum_page>1){    
                $str = "   
";    
            }    
            return $str;    
        }    
        function show_page_select_wap(){    
            if ($this->sum_page>1){    
                $str = "
";    
            }    
            return $str;    
        }    
        function set_url(){    
            parse_str($_SERVER["QUERY_STRING"], $arr_url);    
            unset($arr_url["ipage"]);    
            if (empty($arr_url)){    
                $str = "ipage=";    
            }else{    
                $str = http_build_query($arr_url)."&ipage=";    
            }    
            $this->url = "http://".$_SERVER["HTTP_HOST"].$_SERVER["PHP_SELF"]."?".$str;    
        }    
    }    
?>