PHP检查文件是否包含字符串

Question

我正在尝试查看文件是否包含发送到页面的字符串.我不确定这段代码有什么问题:

?php
    $valid = FALSE;
    $id = $_GET['id'];
    $file = './uuids.txt';

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

if ($handle) {
    // Read file line-by-line
    while (($buffer = fgets($handle)) !== false) {
        if (strpos($buffer, $id) === false)
            $valid = TRUE;
    }
}
fclose($handle);

    if($valid) {
do stufff
}

Answer 1

更简单:

<?php
    if( strpos(file_get_contents("./uuids.txt"),$_GET['id']) !== false) {
        // do stuff
    }
?>

针对内存使用情况的评论:

<?php
    if( exec('grep '.escapeshellarg($_GET['id']).' ./uuids.txt')) {
        // do stuff
    }
?>

Answer 2

搜索较大的文件时,代码更有效.

$handle = fopen('path_to_your_file', 'r');
$valid = false; // init as false
while (($buffer = fgets($handle)) !== false) {
    if (strpos($buffer, $id) !== false) {
        $valid = TRUE;
        break; // Once you find the string, you should break out the loop.
    }      
}
fclose($handle);