php md5_file function with gif file?

问题

I discovered that when I use php md5_file function to get the md5 checksum of the image, the checksum is different everytime.

Is it the gif image or is the md5_file() function that is dynamic?

回答1:

Unless the file contents change this is impossible

md5_file("path/file"); 

If file stays the same the output will be the same hash every time

来源：https://stackoverflow.com/questions/14055780/php-md5-file-function-with-gif-file