How to determine if a file is missing from my server

[Smudly]

When I upload new files, their file name is stored into my database. I have been told that a couple of the file downloads weren't working. Upon further investigation I figured out that the file the person wanted to download was nowhere to be seen in my downloads directory. How can I determine if a file exists in my directory? I assume I can somehow use the location that is stored inside my database (ex: myfile.pdf) and compare that with what's in the folder.

[P0lT10n]

do

if(file_exists(you_dir_to_file_and_file_name)){
// code
}