how to get the file from a folder using php?

Question

i have one folder,in that i have many files and i have four buttons also,the buttons are first,next,previous,last. when i click on first button i want to get first file content and it should display which file currently working on.when i click on next button i want to get next file content,when i click on previous button want to get the previous file content,when i click on last button i want to get the last file content.

$next_slide=$text+"1";
echo $next_slide;
$a_str = array($_POST["content"]);
$contents = implode(PHP_EOL, $a_str);
$contents .= PHP_EOL . PHP_EOL;   
$get_content=file_get_contents($foldername.'/'.$next_slide."-html",$contents);

when i click on first getting first file content,passing the 1 as to php fie and adding +1 for get the next file content,but not get the second file content please help me how to do it?

Answer 1

Try following and -html is not a valid extension

$handler = fopen($foldername.'/'.$next_slide.'.html','r');
$get_content = fread($handler);

Answer 2

You have to save customer choice:

 $choice = 0;
 if(isset($_SESSION['actual'])){
     $choice = $_SESSION['actual']; or COOKIE as you want.
 }
 if($_GET['next']){
      $choice++;
 }
 elseif($_GET['previous']){
      $choice--;
 }
 elseif($_GET['first']){
      $choice = 'first';
 }
 elseif($_GET['last']){
      $choice = 'last';
 }
 $_SESSION['actual'] = $choice;

 $get_content=file_get_contents($foldername.'/'. $choice ."-html",$contents);