How to PHP Error Handling

Basic Error Handling: Using the die() function
The first example shows a simple script that opens a text file:

<?php
$file=fopen("welcome.txt","r");
?>

If the file does not exist you might get an error like this:

Warning: fopen(welcome.txt) [function.fopen]: failed to open stream:
No such file or directory in C:\webfolder\test.php on line 2

To prevent the user from getting an error message like the one above, we test whether the file exist before we try to access it:

<?php
if(!file_exists("welcome.txt")) {
  die("File not found");
} else {
  $file=fopen("welcome.txt","r");
}
?>

Now if the file does not exist you get an error like this:

File not found

The code above is more efficient than the earlier code, because it uses a simple error handling mechanism to stop the script after the error.