PHP File Handling: Read, Write, and Manage Files

Learn reading and writing files in PHP — file_get_contents, file_put_contents, fopen, fwrite.

file_get_contents and file_put_contents

$data = file_get_contents("file.txt");
echo $data;

file_put_contents("file.txt", "Hello World");


#append mode
file_put_contents("file.txt", "New Line\n", FILE_APPEND);

fopen for More Control

$handle = fopen("file.txt", "r");
$content = fread($handle, filesize("file.txt"));
fclose($handle);

File Checks and Management

// Read line by line
if (file_exists($file)) {
    $handle = fopen($file, "r");

    if ($handle) {
        echo "Reading with fopen:\n";
        while (!feof($handle)) {
            echo fgets($handle);
        }
        fclose($handle);
    }
}

// Write using fopen
$handle = fopen($file, "a");
if ($handle) {
    fwrite($handle, "Written using fopen\n");
    fclose($handle);
}



// Exists
if (file_exists($file)) {
    echo "\nFile exists\n";
}

// Permissions
if (is_readable($file)) {
    echo "File is readable\n";
}

if (is_writable($file)) {
    echo "File is writable\n";
}

// Size
echo "File size: " . filesize($file) . " bytes\n";

// Rename
rename($file, "new_file.txt");

// Delete (uncomment to use)
// unlink("new_file.txt");




$logFile = "app.log";

if (!file_exists($logFile)) {
    file_put_contents($logFile, "");
}

$message = date("Y-m-d H:i:s") . " - User logged in\n";
file_put_contents($logFile, $message, FILE_APPEND);

Q: When should I use fopen instead of fle_get_contents?

Use file_get_contents for simple one-shot reads. Use fopen for large files you need to read line-by-line (saving memory), or when you need both reading and writing in the same operation.