リロード、二重ポスト対策
ソース
header
<?php
define(LOG , "./data/dpost.txt");
function counter($up){
$fp = @fopen(LOG , "r+");
flock($fp, LOCK_EX);
$count = fgets($fp);
if ($up) {
$count++;
rewind($fp);
fwrite($fp, $count);
}
flock($fp, LOCK_UN);
fclose($fp);
return $count;
}
if ($_POST['submit']) {
counter(true);
header("Location: {$_SERVER['PHP_SELF']}");
exit;
}
print '
<form action="'.$_SERVER['PHP_SELF'].'" method="post">
<p>
<input type="submit" name="submit" value="送信" />
</p>
</form>
';
$count = counter(false);
print "<p style=\"font-size:200%\">$count</p>";
?>
cookie
<?php
define(LOG , "./data/dpost.txt");
function counter($up){
$fp = @fopen(LOG , "r+");
flock($fp, LOCK_EX);
$count = fgets($fp);
if ($up) {
$count++;
rewind($fp);
fwrite($fp, $count);
}
flock($fp, LOCK_UN);
fclose($fp);
return $count;
}
$error = false;
if ($_POST['submit']) {
if ($_POST["rand"] == $_COOKIE["sample"]) {
//有効期限を設定していない為、ブラウザを閉じた時が有効期限になります
setcookie("sample", 0);
counter(true);
}else{
$error = ture;
}
}else{
mt_srand((double)microtime() * 10000000);
$rand = md5((string)mt_rand());
setcookie("sample", $rand);
}
print '
<form action="'.$_SERVER['PHP_SELF'].'" method="post">
<p>
<input type="hidden" name="rand" value="'.$rand.'" />
<input type="submit" name="submit" value="送信" />
</p>
</form>
';
$count = counter(false);
print "<p style=\"font-size:200%\">$count</p>";
if ($error) {
print "<p style=\"color:red\">二重送信は出来ません</p>";
}
?>
session
<?php
define(LOG , "./data/dpost.txt");
function counter($up){
$fp = @fopen(LOG , "r+");
flock($fp, LOCK_EX);
$count = fgets($fp);
if ($up) {
$count++;
rewind($fp);
fwrite($fp, $count);
}
flock($fp, LOCK_UN);
fclose($fp);
return $count;
}
$error = false;
if ($_POST['submit']) {
session_start();
if ($_POST["rand"] == $_SESSION["sample"]) {
unset($_SESSION["sample"]);
counter(true);
}else{
$error = ture;
}
}else{
mt_srand((double)microtime() * 10000000);
$rand = md5((string)mt_rand());
session_start();
$_SESSION["sample"] = $rand;
}
print '
<form action="'.$_SERVER['PHP_SELF'].'" method="post">
<p>
<input type="hidden" name="rand" value="'.$rand.'" />
<input type="submit" name="submit" value="送信" />
</p>
</form>
';
$count = counter(false);
print "<p style=\"font-size:200%\">$count</p>";
if ($error) {
print "<p style=\"color:red\">二重送信は出来ません</p>";
}
?>
サンプル実行
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