Most of the time, it is enough to just output the error message in $! to the user, so they can figure out what's happening. If you want to find out more about the exact condition, I'd suggest you use the -X operators, e.g.

die "Can't read $_" unless -r;
die "Can't write $_" unless -r;
die "Can't execute $_" unless -x;
die "$_ not a file" unless -f;
die "$_ not a directory" unless -d;
# ...

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In reply to Re: How portable are common $! error codes? by crenz
in thread How portable are common $! error codes? by Anonymous Monk

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