Question

I’m writing a php script that takes some c code and tests it against a few test cases.
But since the source code can have single and double quotes along with slashes, my script doesn’t get the entire data when passed via a textarea. I’m posting using the .ajax method of jQuery

When I tried, here’s what happens

$code_string = $_POST['code'];
echo $code_string;

the input is

int a,b;
scanf("%d%d",&a,&b);
printf("%d",a+b);

The jQuery code that posts the data is

  $('#submitButton').click(
    function(evt){
    userCode = $('#answer').val();
    $.ajax({
    type : 'POST',
    url : 'scripts/php/check_answer.php',
    data : 'code=' + escape( userCode ),
    dataType : 'text',
    success : populateResponseToQuestion
    });

evt.preventDefault;
});

and the output is

int a,b;
scanf("%d%d",&a,&b);
printf("%d",a b);

I want to be able to pass the data to php without anything being trimmed off. In this case the + symbol is lost. With more code, I realize more stuff would be lost or modified.

Answer 1

Your post data is preserved, but if you want it display correctly in HTML document you have to use <br> for new lines, so function nl2br will be helpful. You should also use htmlspecialchars or mentioned earlier htmlentities to avoid problems when posting code with < character (it can be interpreted as opening HTML tag).

[+]

As for JavaScript part, you are doing it wrong. Either use encodeURIComponent() instead of escape() or pass object to the $.ajax:

$.ajax({
    type : 'POST',
    url : 'scripts/php/check_answer.php',
    data : { "code" : userCode },
    dataType : 'text',
    success : populateResponseToQuestion
});

This way jQuery will handle it for you.