小心使用'while(!feof……Fgets()的东西，Fgets可以得到一个错误(返回false)和永远循环而不到达文件的结束。Codaddict是最接近正确的，但当你的'while fgets'循环结束时，检查feof;如果不是真的，那么你就出错了。

你可以为文件使用一个面向对象的接口类——SplFileObject http://php.net/manual/en/splfileobject.fgets.php (PHP 5 >= 5.1.0)

<?php

$file = new SplFileObject("file.txt");

// Loop until we reach the end of the file.
while (!$file->eof()) {
    // Echo one line from the file.
    echo $file->fgets();
}

// Unset the file to call __destruct(), closing the file handle.
$file = null;

SplFileObject在处理大文件时很有用。

function parse_file($filename)
{
    try {
        $file = new SplFileObject($filename);
    } catch (LogicException $exception) {
        die('SplFileObject : '.$exception->getMessage());
    }
    while ($file->valid()) {
        $line = $file->fgets();
        //do something with $line
    }

    //don't forget to free the file handle.
    $file = null;
}

<?php
echo '<meta charset="utf-8">';

$k= 1;
$f= 1;
$fp = fopen("texttranslate.txt", "r");
while(!feof($fp)) {
    $contents = '';
    for($i=1;$i<=1500;$i++){
        echo $k.' -- '. fgets($fp) .'<br>';$k++;
        $contents .= fgets($fp);
    }
    echo '<hr>';
    file_put_contents('Split/new_file_'.$f.'.txt', $contents);$f++;
}
?>

这就是我如何处理非常大的文件(测试高达100G)。它比fgets()快

$block =1024*1024;//1MB or counld be any higher than HDD block_size*2
if ($fh = fopen("file.txt", "r")) { 
    $left='';
    while (!feof($fh)) {// read the file
       $temp = fread($fh, $block);  
       $fgetslines = explode("\n",$temp);
       $fgetslines[0]=$left.$fgetslines[0];
       if(!feof($fh) )$left = array_pop($lines);           
       foreach ($fgetslines as $k => $line) {
           //do smth with $line
        }
     }
}
fclose($fh);

你可以使用fgets()函数逐行读取文件:

$handle = fopen("inputfile.txt", "r");
if ($handle) {
    while (($line = fgets($handle)) !== false) {
        // process the line read.
    }

    fclose($handle);
}