Note, if you call lots of -X operators in succession (i.e. for the same $_), you can use the special filehandle of a single underline to avoid repeating the stat(2) system call: 
die "Can't read $_" unless -r;
die "Can't write $_" unless -w _;
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: Re: How portable are common $! error codes? by ctilmes
in thread How portable are common $! error codes? by Anonymous Monk

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