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  1. <form action="" method="post">
  2. <img src="./?<?php echo session_name()?>=<?php echo session_id()?>">
  3. <input type="text" name="keystring">
  4. <input type="submit" value="Check">
  5. </form>
  6. <?php
  7. if(count($_POST)>0) {
  8. if(isset($_SESSION['captcha_keystring']) && $_SESSION['captcha_keystring'] === $_POST['keystring']){
  9. echo "Верно";
  10. }else{
  11. echo "Ошибка";
  12. }
  13. }
  14. unset($_SESSION['captcha_keystring']);
  15. ?>
Success #stdin #stdout #stderr 0.02s 24448KB
comments (?)
stdin 
Standard input is empty
stdout 
<form action="" method="post">
<img src="./?PHPSESSID=">
<input type="text" name="keystring">
<input type="submit" value="Check">
</form>
stderr 
PHP Notice:  Undefined variable: _SESSION in /home/F7Z6w2/prog.php on line 14
https://ideone.com/993ZNV
language:
PHP (php 7.3.5)
created:
10 years ago
visibility:
public

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