您可以在较小的文件上使用一种方法，该文件可以两次装入您的内存：
$data = file('myfile'); // reads an array of lines
function replace_a_line($data) {
if (stristr($data, 'certain word')) {
return "replaement line!\n";
}
return $data;
}
$data = array_map('replace_a_line',$data);
file_put_contents('myfile', implode('', $data));
快速说明，PHP> 5.3.0支持lambda函数，因此您可以删除命名的函数声明并将映射缩短为：
$data = array_map(function($data) {
return stristr($data,'certain word') ? "replacement line\n" : $data;
}, $data);
从理论上讲，您可以使它成为单个（很难理解）的PHP语句：
file_put_contents('myfile', implode('',
array_map(function($data) {
return stristr($data,'certain word') ? "replacement line\n" : $data;
}, file('myfile'))
));
$reading = fopen('myfile', 'r');
$writing = fopen('myfile.tmp', 'w');
$replaced = false;
while (!feof($reading)) {
$line = fgets($reading);
if (stristr($line,'certain word')) {
$line = "replacement line!\n";
$replaced = true;
}
fputs($writing, $line);
}
fclose($reading); fclose($writing);
// might as well not overwrite the file if we didn't replace anything
if ($replaced)
{
rename('myfile.tmp', 'myfile');
} else {
unlink('myfile.tmp');
}
602392714
清零编程群