How to Replace Text while Maintaining Capitalization?

Question

Say I wanted to a string replace on a file with the following contents

name
nAmE
naMEbb
NAME

And wanted to replace the word "name" with "dave", but keeping the capitalization of the original text. For example, my desired output would be,

dave
dAvE
daVEbb
DAVE

Are there any one-liners to do this (preferably in Perl so I can do an in-place substitution across many files)?

EDIT The problem is ambiguous unless both strings have exactly the same length. Let's assume it does.

Answer 1

There are some solutions on perlFaq: http://perldoc.perl.org/perlfaq6.html#How-do-I-substitute-case-insensitively-on-the-LHS-while-preserving-case-on-the-RHS?

One of solutions presented there allows to perform the substitution in a single line, by defining a subroutine (preserve_case):

   $string = "this is a TEsT case";
   $string =~ s/(test)/preserve_case($1, "success")/egi;
   print "$string\n";

This prints: this is a SUcCESS case