What file format is dat? Function code of PHP mandatory file download function arbitrary file format

Copy the code The code is as follows:

/********************
*@file - path to file
*/
function force_download($file)
{
if ((isset($file))&&(file_exists($file))) {
header("Content-length: ".filesize($file));
header('Content-Type: application/octet-stream');
header('Content-Disposition: attachment; filename="' . $file . '"');
readfile("$file");
} else {
echo "No file selected";
}
}

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Collection of twenty-one practical and convenient PHP function codes

The above introduces what file format dat is. The function code of PHP's mandatory file download function is any file format, including what file format dat is. I hope it will be helpful to friends who are interested in PHP tutorials.