or download this
# for f in `seq 40123`; do echo " #alfa beta"; done | perl -e 'use str
+ict; use warnings; undef $/; my $s = <STDIN>; print length $s, "\n";
+$s =~ /\G (?: \s++ | \# .*+ )++ /xgc; print pos $s, "\n"; '
481476
Complex regular subexpression recursion limit (32766) exceeded at -e l
+ine 1, <STDIN> chunk 1.
196597