This ran in just a few minutes against my big 2GB file.

All I had to do was change the printable range to 33..126, change <DATA> to <>, and for my own curiosity, add print "$1 seen on line $.\n"; after delete $char_hash{$1};

In reply to Re^4: Find what characters never appear by Narveson
in thread Find what characters never appear by Narveson

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