use strict; my $text="the number is 3+4"; print "before: $text\n"; $text =~ s/(\d+)\+(\d+)/&hello($&, $1, $2)/e; print "after: $text\n"; sub hello { my ($line, $n1, $n2)=@_; my $sum=$n1+$n2; return "$line=$sum"; }
before: the number is 3+4 after: the number is 3+4=7