创建前检查文件大小

Question

I'm creating a system to generate sitemaps for a application I'm working on, and one of the requirements for generating sitemaps is that each sitemap shouldn't have a file size greater than 10mb (10,485,760 bytes) as can be seen here.

This is my code to create the sitemap:

$fp = fopen($this->getSitemapPath() . $filename, 'w');
fwrite($fp, $siteMap->__toString());
fclose($fp);

The method $siteMap->__toString() holds a maximum of 50000 links.

Is there a way to check the resulting file size before calling the function fwrite?

Answer 1

Sure, you can use mb_strlen to get the length of your string before you write it out to a file.

$contents = $siteMap->__toString();

if(mb_strlen($contents, '8bit') >= 10485760) {
    echo "Oops, this is too big";
} else {
    fwrite($fp, $contents);
}