Re^2: print number of characters after specific character

[johngg]

With your double split, rather than concatenation in a loop I'd go for join'ing an array slice, although substr seems more suited to the task.

$ perl -E '
$str = q{471234973798375754773971832374974447889743725345932};
say for map { join q{}, ( split m{} )[ 0 .. 9 ] } split m{47}, $str;
say for map { substr $_, 0, 10 } split m{47}, $str;'

1234973798
7397183237
8897437253

1234973798
7397183237
8897437253

$

I hope this is of interest.