PHP — File Handling

Reading files

<?php
// Read entire file
$content = file_get_contents('file.txt');

// Read line by line
$lines = file('file.txt');

// Read with fopen
$handle = fopen('file.txt', 'r');
while (($line = fgets($handle)) !== false) {
    echo $line;
}
fclose($handle);
?>

Writing files

<?php
// Write entire file
file_put_contents('output.txt', 'Hello, World!');

// Append
file_put_contents('output.txt', "\nSecond line", FILE_APPEND);

// Write with fopen
$handle = fopen('output.txt', 'w');
fwrite($handle, "Line 1\n");
fwrite($handle, "Line 2\n");
fclose($handle);
?>

File operations

<?php
// Check existence
if (file_exists('file.txt')) {
    echo 'File exists';
}

// Get file info
echo filesize('file.txt');
echo date('Y-m-d H:i:s', filemtime('file.txt'));

// Copy, rename, delete
copy('file.txt', 'copy.txt');
rename('copy.txt', 'renamed.txt');
unlink('renamed.txt');
?>

Directory operations

<?php
// Create directory
mkdir('newdir', 0755, true);

// List files
$files = scandir('.');
foreach ($files as $file) {
    echo $file . "\n";
}

// Delete directory
rmdir('newdir');
?>

CSV files

<?php
// Read CSV
$handle = fopen('data.csv', 'r');
while (($row = fgetcsv($handle)) !== false) {
    print_r($row);
}
fclose($handle);

// Write CSV
$handle = fopen('output.csv', 'w');
fputcsv($handle, ['Name', 'Age', 'Email']);
fputcsv($handle, ['Alice', 30, 'alice@example.com']);
fclose($handle);
?>

Mini Practice

Write PHP code that:

1. Reads a file line by line
2. Writes data to a CSV file
3. Checks file existence and size
4. Lists files in a directory

Up Next

In the next lesson, you'll learn about Sessions — managing user sessions.