我试图编写这个程序，将文件中的用户名与输入的用户名进行比较，以检查它是否存在，但该程序似乎不起作用。请帮忙。该程序应该打开一个名为allusernames的文件来比较用户名。如果找不到用户名，请将其添加到文件中。
<?php
$valid=1;
$username = $_POST["username"];
$listofusernames = fopen("allusernames.txt", "r") or die("Unable to open");
while(!feof($listofusernames)) {
$cmp = fgets($listofusernames);
$val = strcmp($cmp , $username);
if($val == 0) {
echo ("Choose another user name, the user name you have entered has already been chosen!");
$valid=0;
fclose($listofusernames);
break;
} else {
continue;
}
}
if($valid != 0) {
$finalusers = fopen("allusernames.txt", "a+");
fwrite($finalusers, $username.PHP_EOL);
fclose($finalusers);
?>
您需要替换每行中的换行符/换行符进行比较。
while(!feof($listofusernames)) {
$cmp = fgets($listofusernames);
$cmp = str_replace(array("'r", "'n"), '',$cmp);
$val = strcmp($cmp , $username);
if($val == 0) {
echo ("Choose another user name, the user name you have entered has already been chosen!");
$valid=0;
fclose($listofusernames);
break;
} else {
continue;
}
}
我在你的代码中添加了以下行
$cmp = str_replace(array("'r", "'n"), '',$cmp);
我还没有测试过，但我想知道你是否可以使用之类的东西
<?php
$user = $_POST["username"];
$contents = file_get_contents("allusernames.txt");
$usernames = explode("'n",$contents);
if(in_array($user,$usernames))
{
echo "Choose another username";
}
else
{
$contents .= "'n".$user;
file_put_contents("allusernames.txt",$contents);
}
我认为像文件获取内容之类的东西需要特定版本的PHP，但它们确实让事情变得更好用。
这也假定您的用户名由新行分隔。
Yo可以用以下代码更简单地完成这项工作：
<?php
$username = $_POST["username"];
$listofusernames = 'allusernames.txt';
$content = file($listofusernames);
if(in_array($username, $content)) {
echo ("Choose another user name, the user name you have entered has already been chosen!");
} else {
$content[] = $username . PHP_EOL;
file_put_contents($listofusernames, implode('', $content));
}
?>