Header redirects & Internal Server Errors- the perfect ingredients for a nightmare!

[Davidc316]

So far, nobody else on the forum seems to have had this problem, so I guess I'm the lucky one! But for once I am TOTALLY convinced that I've not done anything wrong! And yet.... PHP is STILL determined to make life very difficult for me.

The trouble is this....

• I have a form that people fill in.

• The form is sent to a PHP page that processes the form details.

• If there is some kind of error in the form (such as the user has left one of the fields blank), then the user will be redirected to an error page.

• The page that the user gets redirected to is dependant on what the nature of the error is.

---

OK, all is well so far and everything above is simple text book stuff.

The trouble is, instead of being redirected to another page, I'm getting internal server errors!

I'm totally convinced that my script is clean and I'll be glad to post it, if anyone is interested. I just can't understand this. How can you have an internal server error for a page that CLEARLY does exist????????

[Norman_Graham]

Hi David

I think you'll have to post the code. I can't think of anything of the top of my head. You sure the form action is correct?

What's the server error?

Norm

[Davidc316]

There are 3 pages involved in this problem:

1. The page with the form that the user fills in.
2. The page that processes the stuff that the user has filled in.
3. The error page (which simply reads an error from the URL and then prints a message depending on what the error is).

Pages 1 and 3 from the above list are fairly simple and probably not worth posting. Page 2 (the page that processses the form) is as follows:

<?php
//clean the data
$name=ucfirst(strip_tags(trim($name)));
$email=strip_tags(trim($email));

//check that they've not left anything blank
if ($name=="") {
header("location: booktesterror.php?error=noname&lotnumber=$lotnumber ");
die();
}
if ($email=="") {
header("location: booktesterror.php?error=noemail&lotnumber=$lotnumber ");
die();
}
if (($day=="empty") OR ($date=="empty") OR ($month=="empty") OR ($year=="empty") OR ($time=="empty")) {
header("location: booktesterror.php?error=incomplete&lotnumber=$lotnumber ");
die();
}

//turn the month into a number
switch ($month) {
 case "January":
   $monthnumber=1;
   break;
 case "February":
   $monthnumber=2;
   break;
 case "March":
   $monthnumber=3;
   break;
 case "April":
   $monthnumber=4;
   break;
 case "May":
   $monthnumber=5;
   break;
 case "June":
   $monthnumber=6;
   break;
 case "July":
   $monthnumber=7;
   break;
 case "August":
   $monthnumber=8;
   break;
 case "September":
   $monthnumber=9;
   break;
 case "October":
   $monthnumber=10;
   break;
 case "November":
   $monthnumber=11;
   break;
 case "December":
   $monthnumber=12;
   break;
}

//CHECK FOR CHRISTMAS
if (($month==December) AND ($date==25)) {
header("location: booktesterror.php?error=christmas&lotnumber=$lotnumber ");
die();
}

//CHECK FOR NEW YEAR
if (($month==January) AND ($date==1)) {
header("location: booktesterror.php?error=newyear&lotnumber=$lotnumber ");
die();
}

//CHECK FOR AN INVALID DATE
$validdate=checkdate($monthnumber, $date, $year);
if ($validdate=="") {
header("location: booktesterror.php?error=invalid&lotnumber=$lotnumber ");
die();
}

//create a unix timestamp
$timeline=$day;
$timeline.=" $date";
$timeline.=" $month";
$timeline.=" $year";
$timeline.=" $time";
$stamptime=strtotime ("$timeline");

//CHECK THAT DATE HAS NOT PASSED
$nowtime=time();
if ($stamptime<$nowtime) {
header("location: booktesterror.php?error=timepast&lotnumber=$lotnumber ");
die();
}

//CHECK FOR AN INVALID DAY
$date_array=getdate($stamptime);
extract($date_array);
if ($weekday==$day) {
} else {
header("location: booktesterror.php?error=wrongday&wrongdate=$stamptime&incorrect=$day&lotnumber=$lotnumber ");
die();
}

//CHECK THAT WE HAVE AT LEAST 24 hours notice
$twentyfourup=$nowtime+86400;
if ($stamptime<$twentyfourup) {
header("location: booktesterror.php?error=needmorenotice&lotnumber=$lotnumber ");
die();
}

//CHECK FOR OVERBOOKED
include("connectiondata.php");
$connection=mysql_connect($host, $user, $password)
  or die ("Ooops! Could not connect to the server.");
$db=mysql_select_db($database, $connection)
  or die ("Ooops! Could not select the database");

$query="select * from cars_testdrive where testdrive_date=$stamptime";
$result=mysql_query("$query") or die (mysql_error()); 
$numrows=mysql_num_rows($result);
if ($numrows>1) {
header("location: booktesterror.php?error=overbooked&lotnumber=$lotnumber ");
die();
}

//CHECK FOR DOUBLE BOOKINGS
$query2="select * from cars_testdrive where lot_number=$lotnumber and testdrive_date=$stamptime";
$result2=mysql_query("$query2") or die (mysql_error()); 
$numrows2=mysql_num_rows($result2);
if ($numrows2>0) {
header("location: booktesterror.php?error=doublebooked&lotnumber=$lotnumber ");
die();
}

//INSERT THE DATA AND SAY THANK YOU
$sql="insert into cars_testdrive (name, email, lot_number, testdrive_date) values ('$name', '$email', '$lotnumber', '$stamptime')";
if (mysql_query($sql, $connection)) {
 print "Record Added!";
} else {
print mysql_error();
} 
?>

The error message that I get is a bog standard Internal Error Message. The exact wording of the error is...

Internal Server Error
The server encountered an internal error or misconfiguration and was unable to complete your request.
Please contact the server administrator, admin@localhost and inform them of the time the error occurred, and anything you might have done that may have caused the error.

More information about this error may be available in the server error log.

---

Apache/1.3.14 Server at localhost Port 80

[Norman_Graham]

Could it possibly be something as simple as the fact that Location: is actually meant to be written with an upper-case 'L'?

http://de3.php.net/manual/en/function.header.php

That ought to produce a PHP error message, though, unless you've switched off error reporting.

Anyway, according to the info in the manual, you may need an absolute URI after Location:, i.e. http://www.mysite.com/booktesterror?..., although some clients might not have a problem with a relative URI.

Norm

[drawmack]

here I've done some work on your script. I have not tested it but I think it will work

BTW: If you ever get a server 500 error IT IS YOUR FAULT, THERE IS AN ERROR IN THE PROGRAM AND YOU PUT IT THERE.

<?php
//register globals is off by default so we'll fix this first
extract($_POST);

//clean the data 
$name=ucfirst(strip_tags(trim($name))); 
$email=strip_tags(trim($email));
$months = array('January'=>1,'February'=>2,'March'=>3,'April'=>4,'May'=5,
                'June'=>6,'July'=>7,'August'=>8,'September'=>9,'October'=>10,
                'November'=>11,'December'=>12);

//check that they've not left anything blank
//TOM: order if statment conditions like this (constant == variable), so that
//the parser can catch the = instead of == error 
if ("" == $name) { 
    header("location: booktesterror.php?error=noname&lotnumber=$lotnumber "); 
    die(); 
} //end if

if ("" == $email) { 
    header("location: booktesterror.php?error=noemail&lotnumber=$lotnumber "); 
    die(); 
} //end if 

//TOM: problem one it's || not OR
if (('empty' == $day) || ('empty' == $date) || ('empty' == $month) ||
    ('empty' == $year) || ('empty' == $time)) { 
    header("location: booktesterror.php?error=incomplete&lotnumber=$lotnumber "); 
    die(); 
} //end if

//turn the month into a number 
$monthnumber = $months[$month];

//CHECK FOR CHRISTMAS 
//TOM: problem 2, you're not quoting string constants, I'm rewritting this to 
//     use numbers instead of strings. 
//TOM: problem 3, it's && in php and not AND
if ((12 == $months[$month]) && (25 == $date)) { 
    header("location: booktesterror.php?error=christmas&lotnumber=$lotnumber "); 
    die(); 
} //end if

//CHECK FOR NEW YEAR 
if ((1 == $months[$month]) && (1 == $date)) { 
    header("location: booktesterror.php?error=newyear&lotnumber=$lotnumber "); 
    die(); 
} //end if

//CHECK FOR AN INVALID DATE 
if ('' == checkdate($monthnumber, $date, $year);) { 
    header("location: booktesterror.php?error=invalid&lotnumber=$lotnumber "); 
    die(); 
} 

//create a unix timestamp 
$stamptime = strtotime($day . ' ' . $date . ' ' . $month . ' ' . $year . ' ' . $time); 

//CHECK THAT DATE HAS NOT PASSED 
if ($stamptime < time()) { 
    header("location: booktesterror.php?error=timepast&lotnumber=$lotnumber "); 
    die(); 
} 

//CHECK FOR AN INVALID DAY 
$date_array=getdate($stamptime); 
extract($date_array); 
if ($weekday != $day) { 
    header("location: booktesterror.php?error=wrongday&wrongdate=$stamptime&incorrect=$day&lotnumber=$lotnumber "); 
    die(); 
} 

//CHECK THAT WE HAVE AT LEAST 24 hours notice 
$twentyfourup = time() + 86400; 
if ($stamptime < $twentyfourup) { 
    header("location: booktesterror.php?error=needmorenotice&lotnumber=$lotnumber "); 
    die(); 
} 

//connect to database
//TOM: You should not be dying here. You really want your user's to see a broke
//     ass site becaues your database is offline for somereason?
include("connectiondata.php"); 
$connection=mysql_connect($host, $user, $password) 
  or die ("Ooops! Could not connect to the server."); 
$db=mysql_select_db($database, $connection) 
  or die ("Ooops! Could not select the database"); 

//CHECK FOR OVERBOOKED 
$query="select * from cars_testdrive where testdrive_date=$stamptime";
//TOM: again a broke ass site cause of a mysql error. 
$result=mysql_query($query) or die (mysql_error());  

if (1 < mysql_num_rows($result)) { 
    header("location: booktesterror.php?error=overbooked&lotnumber=$lotnumber ");
    mysql_close($db); 
    die(); 
} 

//CHECK FOR DOUBLE BOOKINGS 
$query2="select * from cars_testdrive where lot_number=$lotnumber and testdrive_date=$stamptime"; 
//TOM: again a broke ass site cause of a mysql error. 
$result2=mysql_query($query2) or die (mysql_error());  

if (0 <  mysql_num_rows($result2)) { 
    header("location: booktesterror.php?error=doublebooked&lotnumber=$lotnumber "); 
    die(); 
} 

//INSERT THE DATA AND SAY THANK YOU 
$sql  = "INSERT INTO cars_testdrive (name, email, lot_number, testdrive_date) ";
$sql .= "VALUES ('" . $name . "', '" . $email . "', '" . $lotnumber . "', '" . $stamptime . "')"; 
if (mysql_query($sql, $connection)) { 
   echo "Record Added!"; 
} else { 
   echo mysql_error(); 
} //end if  

?>

[Davidc316]

Well, first of all let me say that I can't even begin to tell you how grateful I am for your efforts in sorting out my script.

I took a close look at the stuff that you wrote and tried it out.

There were one or two inevitable parse errors on your script but after I corrected those minor typos I ran the thing and guess what? -it behaved exactly the same as the script that I had written! Yes, that's right.... it got an internal server error.

I've considered the criticisms of my script that you made and I am very grateful for your comments. However, I think that none of the flaws that you mentioned are enough to warrent a 500 Internal Server Error.

Things like using "AND" instead of "&&" or writing "if ($apples=='green') {" instead of "if ('green'==$apples) {" strike me as being simply a matter of choice or personal style that we have as PHP users. The particular style of scriptwriting that I use has never given me any problems before.

I know that this sounds like the ultimate case of a bad worker blaming his tools, but I am starting to seriously suspect that there's a problem with my PHP engine.

I would be happy to send you every single line of code from the original HTML form, to the form processing script (that we've been working on) to the error page... just to see if it works on someone else's computer. However, I certainly wouldn't blame you for not being interested.

The one piece of good news with this mystery is that there is, I think, a better way to write the script anyway- a method that avoids doing all those header redirects and simply deals with the error(s) there and then. I think I'll try that approach instead.

Thanks again for your help.

[Davidc316]

Norman,
thanks for your input. The capital "L" thing was a good theory, but unfortunately I changed it and it didn't make any difference. The relative VS absolute theory is also interesting but I've used relative links loads of times in the past and haven't had any problems at all.

The thing that makes this particular PHP problem so much of a downer for me is the gut feeling that on this particular occassion I have got it right and PHP has got it wrong. I've only ever felt like this once before and on that occassion my webhosts did an investigation and eventually confirmed that their PHP engine had been corrupted.

I have broken my script don't into small sections and tested each section individually. Each section works fine on its own. I just can't understand how it is that when I put everything together it won't work.

Perhaps PHP simply freaks out when you bombard it with lots and lots of different header redirect statements. Maybe that's the flaw.

[Norman_Graham]

Hi David

Not sure if I can be of any help. What I would suggest, though, is that you do indeed adopt a different approach. I read a whole bunch of articles about OOP in PHP when I wanted to put a user-input form on my site and then I created a form with the total feedback and the insertion of the data into the DB (and sending an e-mail to the user and to myself) all in one file. OK - I did move the form-validation class to a different file, purely for structural/recycling reasons, but I basically have an all-singing, all-dancing PHP file which does everything without relocates and file switching. I found this both elegant and efficient. Took me a while to get my head round the OOP approach, but it works very nicely and keeps methods separate from raw data.

Best o luck

Norm

[Davidc316]

I think you're right Norman.

I'll get started on this new script straight away.

Thanks for the advice.

[codeDV]

I've got a few suggestions. You may have already tried some if not all of these but I'll fire away anyway:

1. An internal server error indicates a problem at the server end.

2. Make sure that Location begins with a capital "L". Some web servers will complain otherwise.

3. HTTP 1.1 requires that the location header points to an absolute URI. e.g: Location: http://mydomain.com/myscript.php

4. You can also try creating a CGI script that sends a location header and calling that. This will tell you for sure whether or not its your script.