php - filesize() 始终读取 0 字节，即使文件大小不是 0 字节

Question

我在下面写了一些代码，目前我正在测试，所以代码中没有数据库查询。

下面的代码显示 if(filesize($filename) != 0) 总是转到 else，即使文件不是 0 字节而是 16 字节那里的数据。我一事无成，它似乎总是认为文件是 0 字节。

我认为显示我的代码更容易(可能还有其他错误，但我会边检查边检查每个错误，一个一个地处理它们)。我没有收到任何 PHP 错误或任何错误。

$filename = 'memberlist.txt';
$file_directory = dirname($filename);
$fopen = fopen($filename, 'w+');

// check is file exists and is writable
if(file_exists($filename) && is_writable($file_directory)){

    // clear statcache else filesize could be incorrect
    clearstatcache();

    // for testing, shows 0 bytes even though file is 16 bytes
    // file has inside without quotes:   '1487071595 ; 582'
    echo "The file size is actually ".filesize($filename)." bytes.\n";

    // check if file contains any data, also tried !==
    // always goes to else even though not 0 bytes in size
    if(filesize($filename) != 0){

        // read file into an array
        $fread = file($filename);

        // get current time
        $current_time = time();

        foreach($fread as $read){
            $var   = explode(';', $read);
            $oldtime  = $var[0];
            $member_count = $var[1];
        }
            if($current_time - $oldtime >= 86400){
                // 24 hours or more so we query db and write new member count to file
                echo 'more than 24 hours has passed'; // for testing

            } else {
                // less than 24 hours so don't query db just read member count from file
                echo 'less than 24 hours has passed'; // for testing
            }
    } else { // WE ALWAYS END UP HERE
        // else file is empty so we add data
        $current_time = time().' ; ';
        $member_count = 582; // this value will come from a database
        fwrite($fopen, $current_time.$member_count);
        fclose($fopen);
        //echo "The file is empty so write new data to file. File size is actually ".filesize($filename)." bytes.\n"; 
    }

} else {
    // file either does not exist or cant be written to
    echo 'file does not exist or is not writeable'; // for testing
}

基本上，代码将位于成员(member)列表页面上，该页面当前检索所有成员(member)并计算注册成员(member)的数量。脚本中的要点是，如果时间少于 24 小时，我们从文件中读取 member_count，否则如果 24 小时或更长时间过去了，那么我们查询数据库，获取成员计数并将新数字写入文件，这是为了减少对成员(member)列表页面。

更新 1:

这段代码:

echo "文件大小实际上是 ".filesize($filename)."bytes.\n";

总是输出下面的内容，即使它不是 0 字节。

The file size is actually 0 bytes.

也试过

var_dump (filesize($filename));

输出:

int(0)

Answer 1

您正在使用:

fopen($filename, "w+") 

根据手册 w+ 表示:

Open for reading and writing; place the file pointer at the beginning of the file and truncate the file to zero length. If the file does not exist, attempt to create it.

因此文件大小为 0 是正确的。

你可能需要 r+