Since he italicized his source text, I did a google search with the exact text "replaces everything that is not a digit with a space" which yielded my three results.
Jeff japhy Pinyan,
P.L., P.M., P.O.D, X.S.:
Perl,
regex,
and perlhacker How can we ever be the sold short or the cheated, we who for every service have long ago been overpaid? ~~ Meister Eckhart
Comment on Re^3: How Do I Use the tr Function's 'c' Option?