PHP fclose Function
last modified April 3, 2025
The PHP fclose function closes an open file pointer. It's essential
for proper resource management when working with files in PHP.
Basic Definition
The fclose function closes a file that was opened with fopen
or fsockopen. It returns true on success or false
on failure.
Syntax: fclose(resource $stream): bool. The function frees system
resources associated with the file handle. Always close files when done.
Basic fclose Example
This shows the simplest usage of fclose to close a file handle.
<?php
declare(strict_types=1);
$file = fopen("example.txt", "r");
if ($file) {
// Read or write operations here
fclose($file);
echo "File closed successfully.";
}
This opens a file for reading, then closes it. The fclose call
releases the file resource. Always check if the file opened successfully first.
Closing After Writing
Files should be closed after writing to ensure all data is flushed to disk.
<?php
declare(strict_types=1);
$file = fopen("output.txt", "w");
if ($file) {
fwrite($file, "Hello, World!");
fclose($file);
echo "Data written and file closed.";
}
This writes to a file then closes it. Closing ensures all buffered data is
written. Without fclose, data might remain in buffers.
Error Handling
Proper error handling ensures resources are cleaned up even if errors occur.
<?php
declare(strict_types=1);
$file = @fopen("nonexistent.txt", "r");
if ($file === false) {
echo "Failed to open file.";
} else {
try {
// File operations here
} finally {
fclose($file);
}
}
This demonstrates robust error handling. The finally block ensures
the file is closed even if exceptions occur. Always clean up resources.
Closing Network Connections
fclose can also close network connections opened with fsockopen.
<?php
declare(strict_types=1);
$socket = fsockopen("www.example.com", 80);
if ($socket) {
fwrite($socket, "GET / HTTP/1.0\r\nHost: example.com\r\n\r\n");
// Read response here
fclose($socket);
echo "Network connection closed.";
}
This opens a network connection, sends a request, then closes it. Network resources should be released promptly like file resources.
Multiple File Handles
When working with multiple files, each should be properly closed.
<?php
declare(strict_types=1);
$file1 = fopen("file1.txt", "r");
$file2 = fopen("file2.txt", "w");
if ($file1 && $file2) {
// Process files here
fclose($file1);
fclose($file2);
echo "Both files closed successfully.";
}
This shows proper handling of multiple file handles. Each opened file must be closed individually. The order of closing usually doesn't matter.
Best Practices
- Always Close: Never leave file handles open unnecessarily.
- Error Check: Verify files opened successfully before closing.
- Resource Management: Use try-finally for robust cleanup.
- Buffering: Closing ensures all buffered data is written.
- Performance: Open files only when needed and close promptly.
Source
This tutorial covered the PHP fclose function with practical
examples showing proper file handle management in different scenarios.