讀取大文件最后幾行數據：

/**

* 取文件最后$n行

* @param string $filename 文件路徑

* @param int $n 最后幾行

* @return mixed false表示有錯誤，成功則返回字符串

*/

function FileLastLines($filename,$n){

if(!$fp=fopen($filename,’r')){

echo ”打開文件失敗，請檢查文件路徑是否正確，路徑和文件名不要包含中文”;

return false;

}

$pos=-2;

$eof=”";

$str=”";

while($n>0){

while($eof!=”n”){

if(!fseek($fp,$pos,SEEK_END)){

$eof=fgetc($fp);

$pos–;

}else{

break;

}

}

$str.=fgets($fp);

$eof=”";

$n–;

}

return $str;

}

echo nl2br(FileLastLines(‘sss.txt’,4));

/**? * 取文件最后$n行? * @param string $filename 文件路徑? * @param int $n 最后幾行? * @return mixed false表示有錯誤，成功則返回字符串? */ function FileLastLines($filename,$n){???? if(!$fp=fopen($filename,'r')){???????? echo "打開文件失敗，請檢查文件路徑是否正確，路徑和文件名不要包含中文";???????? return false;???? }???? $pos=-2;???? $eof="";???? $str="";???? while($n>0){???????? while($eof!="n"){???????????? if(!fseek($fp,$pos,SEEK_END)){???????????????? $eof=fgetc($fp);???????????????? $pos--;???????????? }else{???????????????? break;???????????? }???????? }???????? $str.=fgets($fp);???????? $eof="";???????? $n--;???? }???? return $str; } echo nl2br(FileLastLines('sss.txt',4));

function tail($fp,$n,$base=5)

{

assert($n>0);

$pos = $n 1;

$lines = array();

while(count($lines)< =$n){

try{

fseek($fp,-$pos,SEEK_END);

} catch (Exception $e){

fseek(0);

break;

}

$pos *= $base;

while(!feof($fp)){

array_unshift($lines,fgets($fp));

}

}

return array_slice($lines,0,$n);

}

var_dump(tail(fopen("access.log","r "),10));

$fp = fopen($file, "r");

$line = 10;

$pos = -2;

$t = " ";

$data = "";

while ($line > 0) {

while ($t != "n") {

fseek($fp, $pos, SEEK_END);

$t = fgetc($fp);

$pos --;

}

$t = " ";

$data .= fgets($fp);

$line --;

}

fclose ($fp);

echo $data