PHP 长文章分页函数 带使用方法，不会分割段落

<?php function ff_page($content,$page)
{
global $expert_id;
$PageLength = 2000; //每页字数
$CLength = strlen($content);
$PageCount = floor(($CLength / $PageLength)) + 1; //计算页数
$PageArray=array();
$Seperator = array("\n","\r","。","！","？","；","，","”","'"); //分隔符号

//echo "页数：".$PageCount."<br>";
//echo "长度：".$CLength."<br><br><br>";
//strpos() 函数返回字符串在另一个字符串中第一次出现的位置
if($CLength<$PageLength)
{
echo $content;

}else{

$PageArray[0]=0;
$Pos = 0;
$i=0;
//第一页
for($j=0;$j<sizeof($Seperator);$j++)
{
//echo $Seperator[$j];
$Pos=strpos($content,$Seperator[$j],$PageArray[$i]+1900);
while($Pos > 0 && $Pos < ($i+1)*$PageLength && $Pos > $i*$PageLength )
{
$PageArray[$i] = $Pos ;
$Pos = strpos($Pos+$PageLength,$content,$Seperator[$j]) ;
}
if($PageArray[$i]>0)
{
$j = $j + sizeof($Seperator) + 1;
}
}

//---
for($i=1;$i<$PageCount-1;$i++){

for($j=0;$j<sizeof($Seperator);$j++)
{
//echo $Seperator[$j];
$Pos=strpos($content,$Seperator[$j],$PageArray[$i-1]+1900);
while($Pos > 0 && $Pos < ($i+1)*$PageLength && $Pos > $i*$PageLength )
{
$PageArray[$i] = $Pos ;
$Pos = strpos($Pos+$PageLength,$content,$Seperator[$j]) ;
}
if($PageArray[$i]>0)
{
$j = $j + sizeof($Seperator) + 1;
}
}
}


//--最后一页
$PageArray[$PageCount-1]=$CLength;

//$page=2;
if($page==1)
{
$output=substr($content,0,$PageArray[$page-1]+2);

}
if($page>1 && $page<=$PageCount)
{
$output=substr($content,$PageArray[$page-2]+2,$PageArray[$page-1]-$PageArray[$page-2]);
$output=" （上接第".($page-1)."页）\n".$output;
}

echo str_replace("\n","<br>&nbsp;&nbsp;&nbsp;",$output);
//if($page==$PageCount)
//return $output=substr($content,$PageArray[$page-2]+2,$PageArray[$page-1]-$PageArray[$page-2]);

if($PageCount>1)
{
echo "<br><br><br><center>";
echo "<font color='ff0000'>".$page."</font>/".$PageCount." 页 &nbsp;";
if($page>1)
echo "<a href=https://www.jb51.net/$PHP_SELF?expert_id=$expert_id&page_t=".($page-1).">上一页</a> ";
else
echo "上一页 ";

for($i=1;$i<=$PageCount;$i++)
{

echo "<a href=https://www.jb51.net/$PHP_SELF?expert_id=$expert_id&page_t=".$i.">[".$i."]</a> ";
}

if($page<$PageCount)
echo " <a href=https://www.jb51.net/$PHP_SELF?expert_id=$expert_id&page_t=".($page+1).">下一页</a> ";
else
echo " 下一页 ";

echo "</center>";
}
}

}?>