我正在使用下面的PHP代码来写入我的wall.txt文件。它运行良好，但问题是wall.txt文件大小不断增加。我想在3段之后添加新数据后修剪wall.txt文件。旧段落将被删除，而新段落将被添加
这是php文件
<?php
$joke = $_POST['AndroidString'];
$complexString = ($joke . "|" . date("l") . ", " . date("jS 'of F Y h:i:s A"));
$endLineStericks = "****";
$registrationFile = fopen("wall.txt", "a") or die("Unable to open file!");
fwrite($registrationFile, $complexString);
fwrite($registrationFile, "'n");
fwrite($registrationFile, $endLineStericks);
fwrite($registrationFile, "'n");
fclose($registrationFile);
?>
这是文本文件
男孩：校长太笨了！/-%/女孩：你知道我是谁吗？/-%/男孩：不…/-%/女孩：我是校长的女儿！/-%/男孩：你知道是谁吗我是？/-%/女孩：不……/-%/男孩：好走开|星期五下午05:23:04****男孩：打911喂？我需要你的帮助！/-%/911：好吧，是什么？/-%/男孩：两个女孩在为我打架！/-%/911：那么你的紧急情况？/-%/男孩：丑陋的那个赢了|星期五，下午05:36:19****最接近我™我今年节食了，从我的浏览器历史记录中删除了食物搜索。/-%//-%/Lollzzzzz:p|星期五，下午05:44:35
使用file和array_slice函数的解决方案：
define("WALL", "wall.txt");
$joke = $_POST['AndroidString'];
fopen(WALL, 'a') || die("Failed to open file!");
$contents = file(WALL); // gets file contents as array of strings(lines)
$complexString = ($joke . "|" . date("l") . ", " . date("jS 'of F Y h:i:s A")). PHP_EOL;
$endLineStericks = "****" . PHP_EOL;
$contents = array_merge($contents, [$complexString, $endLineStericks]);
// if there were at least three records(including end stricks) in wall.txt
if (count($contents) > 6) {
$contents = array_slice($contents, -6); // getting last three records
}
file_put_contents(WALL, implode("", $contents));