Regexp?

$ perl -e '$_ = "xoxo";$_=ucfirst(reverse(ucfirst(reverse($_))));print
+'
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Yes, this _is_ faster than any regular expression.

#!/usr/bin/perl -wl

use strict;

 my $foo="xoxoxoxoxoxoxoxoxoxoxoxoxoxoxox";
 $foo=~s/^(.)(.+?)(.)$/\U$1\E\L$2\E\U$3\E/;
 print $foo;
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This soluction does work, but it does force all the letters inbetween the first and last to lowercase. If you want to leave them alone then you should use this:



#!/usr/bin/perl -wl

use strict;

my $foo="xoxoxoxoxoxoxoxoxoxoxoxoxoxoxox";
$foo =~ s/^(.)(.*)(.)$/\U$1\E$2\U$3/;
print "$foo\n";

#Output: XoxoxoxoxoxoxoxoxoxoxoxoxoxoxoX

my $bar="xoXOxoXOxoXOxoXOxoXOxoXOxo";
$bar =~ s/^(.)(.*)(.)$/\U$1\E$2\U$3/;
print "$bar\n";

#Ooutput: XoXOxoXOxoXOxoXOxoXOxoXOxO
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The original question was worded with what to do with the middle segment was up in the air. Just trying to add clarification for posterity :)

Both your solution and husoft's fail on a single character string. As "x" consists of a single character and that character is both the first and the last it should be capitalized.

-sauoq
"My two cents aren't worth a dime.";

As I mentioned in my reply to Helter, your solution fails on a single character string. Worse, it requires a string to have 3 characters at a minimum. (I also agree that lowercasing the middle portion is probably wrong.)

-sauoq
"My two cents aren't worth a dime.";

I dont think that lowercasing the middle is wrong.
$foo="XOXOXOXOXOXOXOXOXOXOXOXOXOXXO";
you will need to lowercase the middle!...

#!/usr/bin/perl

use strict;
use warnings;

my @strings = qw/foo BAR Baz blah q/;


foreach (@strings) {
    # leave string as is
    print ucfirst(reverse(ucfirst(reverse()))),"\n";    
    # or lc everything else
    print ucfirst(reverse(ucfirst(reverse(lc())))),"\n";

}
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UPDATE: well that serves me right for not refreshing my browser, looks like I had the same idea as fruiture

I would do it in two steps.

Update: Well, maybe one step:

-sauoq
"My two cents aren't worth a dime.";

Don't use a regexp, you don't need it and it'll only make things more complicated. Just alter each character individually.

for (0, -1)
  {
    $bar = substr $foo, $_, 1;
    $foo = substr($foo, $_, 1) = uc bar;
  }
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But if you really do want to use a Regex the following will work and does so for the special cases of one or two letter words.

s/\b\w|\w\b/\U$&\E/g
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or if you don't want "toasted weasels" to go to "ToasteD WeaselS" but "Toasted weaselS" then:

s/\A\w|\w\z/\U$&\E/g
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Dedalus.