note 86248 modified in function.fseek by felipe

read x lines from log file end

marc dot roe at gmail dot com improved a bit speed
but this makes reading even more faster :)

test on my server:
2megs file with his function read elapsed 5 sec vs mines 0.03 sec

faster with large and small file 

<?php
function __file_backread_helper(&$haystack,$needle,$x)
{
	$pos=0;$cnt=0;	
	while( $cnt < $x && ($pos=strpos($haystack,$needle,$pos)) !==false ){$pos++;$cnt++;}	
	return $pos==false ? false:substr($haystack,$pos,strlen($haystack));
}

function file_backread($file,$lines,&$fsize=0){
	$f=fopen($file,'r');
	if(!$f)return Array();
	
	
	$splits=$lines*50;
	if($splits>10000)$splits=10000;

	$fsize=filesize($file);
	$pos=$fsize;
	
	$buff1=Array();
	$cnt=0;

	while($pos)
	{
		$pos=$pos-$splits;
		
		if($pos<0){ $splits+=$pos; $pos=0;}

		fseek($f,$pos);
		$buff=fread($f,$splits);
		if(!$buff)break;
		
		$lines -= substr_count($buff, "\n");

		if($lines <= 0)
		{
			$buff1[] = __file_backread_helper($buff,"\n",abs($lines)+1);
			break;
		}
		$buff1[] = $buff;
	}

	return str_replace("\r",'',implode('',array_reverse($buff1)));
}
?>

end of dirty code

--was--
read x lines from log file end

marc dot roe at gmail dot com improved a bit speed
but this makes reading even more faster :)

test on my server:
2megs file with his function read elapsed 5 sec vs mines 0.03 sec

faster with large and small file 

function __file_backread_helper(&$haystack,$needle,$x)
{
	$pos=0;$cnt=0;	
	while( $cnt < $x && ($pos=strpos($haystack,$needle,$pos)) !==false ){$pos++;$cnt++;}	
	return $pos==false ? false:substr($haystack,$pos,strlen($haystack));
}

function file_backread($file,$lines,&$fsize=0){
	$f=fopen($file,'r');
	if(!$f)return Array();
	
	
	$splits=$lines*50;
	if($splits>10000)$splits=10000;

	$fsize=filesize($file);
	$pos=$fsize;
	
	$buff1=Array();
	$cnt=0;

	while($pos)
	{
		$pos=$pos-$splits;
		
		if($pos<0){ $splits+=$pos; $pos=0;}

		fseek($f,$pos);
		$buff=fread($f,$splits);
		if(!$buff)break;
		
		$lines -= substr_count($buff, "\n");

		if($lines <= 0)
		{
			$buff1[] = __file_backread_helper($buff,"\n",abs($lines)+1);
			break;
		}
		$buff1[] = $buff;
	}

	return str_replace("\r",'',implode('',array_reverse($buff1)));
}

end of dirty code

http://php.net/manual/en/function.fseek.php