This is a tutorial on using Perl's warn and die signals. It is based on a post I made some time ago, here, but covers more of the details and raises more of the pitfalls. In this tutorial I attempt to separate the warn and die signals from the OS signals, explain how they are used and what they can be used for, and explore the problems that can come up.
Traditionally, Unix/Linux/POSIX filenames can be almost any sequence of bytes, and their meaning is unassigned. The only real rules are that "/" is always the directory separator, and that filenames can't contain byte 0 (because this is the terminator). Although this is flexible, this creates many unnecessary problems. In particular, this lack of limitations makes it unnecessarily difficult to write correct programs (enabling many security flaws), makes it impossible to consistently and accurately display filenames, causes portability problems, and confuses users. more ....
Comments