File Test Operators

Perl has a set of file test operators that let you get particular information about files. They all take the form of -X, where the X represents the particular test (and there is a literal -X file test operator too, to confuse things a bit). In most cases, these operators return true or false. Although we call these things operators, you’ll find their documentation in perlfunc.^[303]

Before you start a program that creates a new file, you might want to ensure that the file doesn’t already exist so that you don’t accidentally overwrite a vital spreadsheet data file or that important birthday calendar. For this, you can use the -e file test, testing a filename for existence: