PHP's file_exists() will not work for me?

The file_exists() function in PHP can be used to check if a file exists on the file system. However, if the file is located on a remote server or the file permission is not set correctly, the function may not be able to access the file and therefore will return false. In that case, you can try using other functions like curl_exec() or get_headers() to check if the file exists or not.

Here's an example of how you can use file_exists in PHP to check if a file exists and output the result:

<?php

$filename = "example.txt";

if (file_exists($filename)) {
  echo "The file '$filename' exists." . PHP_EOL;
} else {
  echo "The file '$filename' does not exist." . PHP_EOL;
}

In this code, the file_exists function is used to check if the file example.txt exists. If the file exists, the function returns true, and the code inside the if block is executed, echoing the message "The file 'example.txt' exists.". If the file does not exist, the function returns false, and the code inside the else block is executed, echoing the message "The file 'example.txt' does not exist.".

Here's another example of using file_exists to check if a directory exists:

<?php

$dirname = "example_dir";

if (file_exists($dirname) && is_dir($dirname)) {
  echo "The directory '$dirname' exists." . PHP_EOL;
} else {
  echo "The directory '$dirname' does not exist." . PHP_EOL;
}

In this code, file_exists is used to check if the directory example_dir exists. If the directory exists, the function returns true. The is_dir function is used to check if the path specified by $dirname is a directory. If $dirname is a directory, the code inside the if block is executed, echoing the message "The directory 'example_dir' exists.". If $dirname is not a directory, the code inside the else block is executed, echoing the message "The directory 'example_dir' does not exist.".