Chapter 11. File Tests
Earlier, we showed how to open a filehandle for output. Normally, that will create a new file, wiping out any existing file with the same name. Perhaps you want to check that there isn't a file by that name. Perhaps you need to know how old a given file is. Or perhaps you want to go through a list of files to find which ones are larger than a certain number of bytes and not accessed for a certain amount of time. Perl has a complete set of tests you can use to find information about files.