Just to further highlight some of the things tadman mentions: Strings may have punctuation after the final word and some words may have an apostrophe or hyphen(s). You can tune a regex to grab whatever you consider to be words in a s/// operation and apply the \u and \L escapes as needed in the replacement. Here is one potential solution: 

    #!/usr/bin/perl -w
    use strict;
    while(<DATA>){
        s/\b(\w+(?:['-]\w+)*)\b/\L\u$1/g;
        s/(\w+(?:['-]\w+)*[\W\s]*)$/\U$1/;
        print;
    }
    __DATA__
    tHis IS just one exAMPle, note:
    some STRINGS haVe apOStrophEs or hyPHens, and
    perhaps faulty punctuation or trailing elipsis ...
    doN't SETTLE for over-THE-counter sOLutions! !!
    including this one.

[download]

I hope this isn't homework, but if it is please do yourself a favor and read up on regexen (perlre) and the various case-functions (uc, lc, ucfirst, and lcfirst), and their equivalent double-quoted string escapes (perlop, in the section "Quote and Quote-like Operators").

In reply to Re: Re: Mixing the case of a line by danger
in thread Mixing the case of a line by Joes

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