Writing to a PHP file - php

Question

I'm trying to write a basic error form to a file, but when I submit the file my PHP always crashes. I've tried some basic error fixes such as whether or not the if statement is occurring, if all the variables I'm using are not null, etc...
In my code all the string variables are valid an I am 100% certain they are not causing the error.
I've reduced it down through error testing to be the lines
$destination = fopen($filename,"w");
and
$fclose($destination);
My code:
if(isset($_POST['submit']) && $_POST['name'] != "" && $_POST['email'] != ""){
$filename = "message_" . date('Y-m-d H:i:s') . ".txt";
$issueType = "Type of issue: " . $_POST["issues"] . "\r\n";
$submitter = "Submitted by: " . $_POST["name"];
$email = "Email ID: " . $_POST["email"];
$time = "Submitted at: " . date('Y-m-d H:i:s') . "\r\n";
$message = "Details: " . $_POST["details"];
$destination = fopen($filename,"w");
fwrite($destination,"Issue Alert!");
fwrite($destination,$issueType);
fwrite($destination,$submitter);
fwrite($destination,$email);
fwrite($destination,$time);
fwrite($destination,$message);
$fclose($destination);
}
Any other code I'm implementing is irrelevant as I've cut off those as being points of error.
When I try this with basic, hard-coded strings I don't get any errors. All help is appreciated, Thanks!

Answer 1

Try to change your $filename, as you wrote
$filename = "message_" . date('Y-m-d H:i:s') . ".txt";
because you can't use colon ( ':' from 'H:i:s') in file name.
maybe you can try this:
$filename = "message_" . date('U') . ".txt";
you still have date-time information in your file name
But remember, if you have big traffic on your site, maybe you will get same file name in one second, and the previous existing file will overwrited