PHP compress file without library

compress.php

function compress_file($input_file, $output_file) {
    // Open the input file for reading
    $input_handle = fopen($input_file, 'rb');
    if (!$input_handle) {
        echo "Failed to open input file\n";
        return;
    }

    // Open the output file for writing
    $output_handle = fopen($output_file, 'wb');
    if (!$output_handle) {
        echo "Failed to open output file\n";
        return;
    }

    // Read the input file into a buffer
    $input_buffer = file_get_contents($input_file);

    // Compress the input buffer using RLE
    $output_buffer = '';
    $current_byte = $input_buffer[0];
    $count = 1;
    for ($i = 1; $i < strlen($input_buffer); $i++) {
        if ($input_buffer[$i] === $current_byte && $count < 255) {
            $count++;
        } else {
            $output_buffer .= chr($count) . $current_byte;
            $current_byte = $input_buffer[$i];
            $count = 1;
        }
    }
    $output_buffer .= chr($count) . $current_byte;

    // Write the compressed buffer to the output file
    fwrite($output_handle, $output_buffer);

    // Close the input and output files
    fclose($input_handle);
    fclose($output_handle);
}

// Compress a file
compress_file('input.bin', 'output.bin');