php将时间差转换为字符串提示

<?php
class timeago
{
static $timeagoobject;
private $rustle;
private $unit;
private function __construct()
{
}
private function __clone(){ }
public static function getobject()
{
if(! (self::$timeagoobject instanceof self) )
self::$timeagoobject = new timeago();
return self::$timeagoobject;
}
private function count_int($unix_c) // main function
{
if(! (isset($unix_c) || is_numeric($unix_c)) )
return 'don\'t find parameter';
$d = time()-$unix_c ; // $d - unix time difference value
$d_int =(int)floor($d/60) ; // minimum unit -- minutes unix/60
$this->unit = 0 ; // is minutes,hour or day?
if($d_int < 60){ // minutes in one hour 3600
$this->rustle = $d_int;
$this->unit = 1;
}
else if($d_int < 720){ //hour in one day 3600*12
$this->rustle = floor($d_int/60);
$this->unit = 2 ;
}
else if($d_int < 7200){ //day in ten days 3600*12*10
$this->rustle = floor($d_int/720);
$this->unit = 3 ;
}
else{
$this->rustle = $d ;
$this->unit = 4 ;
}
}
public function piece_str($c)
{
$this->count_int($c);
$u = '';
switch( $this->unit )
{
case 1:
$u = 'minute';
break;
case 2:
$u = 'hour';
break;
case 3:
$u = 'day';
break;
case 4:
$u = '';
break;
case 0:
return 'sorry , get time is fail';
}
if($this->unit < 4)
{
if($this->rustle > 1)
return (string)$this->rustle.$u.'s ago';
else if($this->rustle == 1)
return (string)$this->rustle.$u.'ago';
else
return 'just now';
}
}
/* example: $ago = timeago::getobject();
* echo $ago->piece_str($unix);
* // 2 days ago
*/
}
?>