What is fclose() in PHP?

The fclose() function is used to close an open file pointer in PHP.

• When you open a file using fopen(), PHP keeps a connection to that file.
• After you are done working with the file (reading, writing, etc.), you should close it using fclose() to free up system resources.

Syntax

fclose(resource $stream): bool

• $stream: This is the file pointer resource (the variable returned by fopen()).
• It returns:
  • true if the file is successfully closed.
  • false if an error occurs.

Simple Example

<?php
// Open a file for reading
$file = fopen("example.txt", "r");

if ($file) {
    // Read the first line
    echo fgets($file);

    // Close the file
    fclose($file);
} else {
    echo "Unable to open file!";
}
?>

Explanation:

• fopen("example.txt", "r") opens the file in read mode.
• fgets($file) reads a line.
• fclose($file) closes the file after reading.

Why is fclose() important?

• Prevents memory leaks.
• Releases the lock on a file (important if many users/programs are accessing the same file).
• Good practice: Always close a file after finishing work with it.

Another Example with Writing

<?php
// Open a file for writing
$file = fopen("sample.txt", "w");

if ($file) {
    fwrite($file, "Hello, world!");

    // Important to close the file after writing
    fclose($file);

    echo "Data written and file closed successfully.";
} else {
    echo "Unable to open file!";
}
?>

Here, after writing "Hello, world!" into sample.txt, we close the file using fclose().

What happens if you don't use fclose()?

• PHP usually automatically closes files at the end of the script.
• But manually closing with fclose() is safer and more reliable, especially in large scripts or when handling multiple files.