使用fwrite从文本文档中删除特定数据 - Deleting specific data from a text document using fwrite?

Deleting specific data from a text document using fwrite?

我正在为我的迷你社交网络写一个"unfriend"脚本，基本上unfriend动作需要从他们的朋友列表中删除他们的id: $user和我的id: $my_id。我已经制作了将用户id添加到每个用户文件的脚本，但我不确定如何删除这个?

我的friend_list文件:1,2,3 // I am user 1

其friend_list文件:1,2,3 // They are user 3

我目前使用这个来添加每个id到文本文件:

if($action === 'accept'){
    mysql_query("DELETE FROM `friend_req` WHERE `from`='$user' AND `to`='$my_id'");
    $fp = fopen($user_data['friend_list'], 'a');
    fwrite($fp, ",".$user."");
    fclose($fp);
    $their_id = friend_list_from_user_id($user);
    $fp = fopen($their_id, 'a');
    fwrite($fp, ",".$my_id."");
    fclose($fp);
}

但是要从他们的friend_list和他们的$user id从我的friend_list中删除$my_id，我想我需要使用这样的东西，但它不起作用:

if($action === 'unfriend'){
    $fp = fopen($user_data['friend_list'], 'a');
    unset($user);
    fclose($fp);
    $their_id = friend_list_from_user_id($user);
    unset($my_id);
    fclose($fp);
}

但是这似乎不起作用，我应该怎么做才能从相应的文件中只删除指定的用户名?

哦，还有，这可能有用，也可能没用:

$myFile = $file;
$fh = fopen($myFile, 'r');
$theData = fgets($fh);
fclose($fh);
$friend = explode(',', $theData);
for($i=0; $i < count($friend); $i++){
    if($i >= 0)
    {
        if($friend[$i] == $user_id) {
        $their_user_id = $user_id;
    }
}

要解决您的问题，只需这样做:

//get the contents of the file
$contents = file_get_contents($user_data['friend_list']);
$contents = str_replace(",".$friend_id, "", $contents); //remove the friend's id
//open the file again and rewrite the whole thing with the new contents without that id
$fp = fopen($user_data['friend_list'], 'w+');
fwrite($fp, $contents);
fclose($fp);