What are common pitfalls or gotchas with stat and file test operators (-e -f -d)?

When working with Perl's stat and file test operators like -e, -f, and -d, there are several common pitfalls and gotchas to keep in mind:

Common Pitfalls

• Symbolic Links: Using -f and -d on symbolic links can yield unexpected results if the target does not exist.
• Permissions: If your script does not have permission to access the file, the file test operators may return false negatives.
• Race Conditions: The state of the file can change between the time you check it and the time you use it, leading to race conditions in a multi-threaded or multi-process environment.
• Path Issues: Always ensure you are checking the right path; relative paths can lead to confusion.

Example

if (-e "example.txt") {
        print "File exists.\n";
    } else {
        print "File does not exist.\n";
    }