use strict;
my $str = '32/34, 36/38, 40/42, 44/46
40/42/44/46/48
58/60
39-42
40-50-60
24-25,26,28,30
36 40,5 44
';
my $regex = qr/(?<=^|$|[\s,\/-])(?:(?P<var1>(?<![\/-])(?!(?:(\d+(?:[,.][05])?)[\/-]){2}(?-1))(\d+(?:[,.][05])?)[\/-](?-1)|(?-1)))(?=^|$|[\s,\/-])/uip;
my $subst = '\\g<var1>\\n';
my $result = $str =~ s/$regex/$subst/rg;
print "The result of the substitution is' $result\n";
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Perl, please visit: http://perldoc.perl.org/perlre.html