Read the docs for -d

If any of the file tests (or either the stat or lstat operators) are given the special filehandle consisting of a solitary underline, then the stat structure of the previous file test (or stat operator) is used, saving a system call.

A few notes and examples follow.

In reply to Re: What does _ mean? by ikegami
in thread What does _ mean? by bichonfrise74

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