filesize(): size of a specified file in bytes

$file = __DIR__ . '/download.zip';
if (is_file($file)) {
    clearstatcache(true, $file);
    $bytes = filesize($file);
    if ($bytes !== false) {
        echo $bytes . ' bytes';
    }
}

echo filesize('test.htm');

130

Size of all files of directory

$ar=scandir('.'); // current dir
while (list ($key, $val) = each ($ar)) { 
echo $val . filesize($val). " bytes " ;
echo "<br>";
}

Handling Non-Existent Files with filesize()

if (!file_exists('sample.txt')) {
    echo 'File does not exist';
} else {
    echo 'File size: ' . filesize('sample.txt') . ' bytes';
}

Example: Convert Bytes to KB, MB, GB Automatically

function format_size($size) {
    $units = ['B', 'KB', 'MB', 'GB', 'TB'];
    $unit_index = 0;
    while ($size >= 1024 && $unit_index < count($units) - 1) {
        $size /= 1024;
        $unit_index++;
    }
    return round($size, 2) . ' ' . $units[$unit_index];
}

$file_size = filesize('sample.txt');
echo 'Formatted size: ' . format_size($file_size);

Use Case: Handling Multiple File Sizes in a Directory

$dir = 'path/to/directory';
$files = scandir($dir);
foreach ($files as $file) {
    if (is_file("$dir/$file")) {
        echo "$file: " . filesize("$dir/$file") . " bytes
";
    }
}

Example: Using filesize() with a Remote URL

$url = 'http://example.com/sample.jpg';
$headers = get_headers($url, 1);
if (isset($headers['Content-Length'])) {
    echo 'File size: ' . $headers['Content-Length'] . ' bytes';
} else {
    echo 'Unable to determine file size.';
}

Example: Checking File Size in a Different Directory

$file_path = '/var/www/html/sample.txt';
if (file_exists($file_path)) {
    echo 'File size: ' . filesize($file_path) . ' bytes';
} else {
    echo 'File does not exist';
}

Example: Handling Large Files

$file_path = 'large_file.zip';
if (file_exists($file_path)) {
    $file_size = filesize($file_path);
    echo $file_size > 1_000_000 ? 'File size is greater than 1MB' : 'File size is less than 1MB';
} else {
    echo 'File does not exist';
}

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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