使用PHP从文件末尾删除行

<?php
// 打开文件
$file = "example.txt";
$handle = fopen($file, "r+");

// 定位到文件末尾
fseek($handle, -1, SEEK_END);
$char = fgetc($handle);

// 判断文件末尾是否为空行
while ($char === "\n" || $char === "\r") {
    fseek($handle, -2, SEEK_END);
    $char = fgetc($handle);
}

// 读取行
$line = "";
while ($char !== false && $char !== "\n" && $char !== "\r") {
    $line .= $char;
    fseek($handle, -2, SEEK_CUR);
    $char = fgetc($handle);
}

// 删除行
fseek($handle, -1, SEEK_CUR);
ftruncate($handle, ftell($handle));

// 关闭文件
fclose($handle);
?>