Using PHP file_exists() to Check File and Directory Existence

In PHP programming, the file_exists() function is used to determine whether a specified file or directory exists, enabling appropriate handling based on the result.

Syntax:

bool file_exists ( string $filename )

Parameter:

$filename : The path of the file or directory to be checked.

Return value: Returns true if the file or directory exists, otherwise false .

Example: The following code demonstrates how to use file_exists() to check a file and a directory.

<?php
// Check if a file exists
$file = 'example.txt';
if (file_exists($file)) {
echo "File exists.";
} else {
echo "File does not exist.";
}
// Check if a directory exists
$dir = 'example_dir';
if (file_exists($dir) && is_dir($dir)) {
echo "Directory exists.";
} else {
echo "Directory does not exist.";
}
?>

The script first defines a file path variable $file and uses file_exists() to verify its existence, outputting a corresponding message. It then defines a directory path variable $dir and checks both existence and that it is a directory using file_exists() together with is_dir() .

Notes:

The file_exists() function can check both local and remote files by providing a URL as the argument.

The function does not differentiate between files and directories; it returns true for either.

It only reports existence and does not impose access restrictions.

It is advisable to use is_readable() or is_writable() before accessing a file to avoid permission‑related errors.

Conclusion: file_exists() is a fundamental PHP function for verifying the presence of files or directories, and when combined with proper conditional checks, it helps ensure correct and secure file handling in backend applications.