When should I update lastmod value in the sitemap?
I have a website like Stackoverflow. I’m creating a sitemap for it. I want to know, what timestamp should be as the value of last-modified for a page? (a question and all its answers)
last-modified
How to check if directory contents has changed with PHP?
I’m writing a photo gallery script in PHP and have a single directory where the user will store their pictures. I’m attempting to set up page caching and have the cache refresh only if the contents of the directory has changed. I thought I could do this by caching the last modified time of the directory using the filemtime() function and compare it to the current modified time of the directory. However, as I’ve come to realize, the directory modified time does not change as files are added or removed from that directory (at least on Windows, not sure about Linux machines yet).