http://qs321.pair.com?node_id=148757

vladb has asked for the wisdom of the Perl Monks concerning the following question:

Good day, monks.. I'm working on a small parser and in this script I require a function that would be able to return a special 'escape' (excuse me for poor jargon) character (such as'\U' etc) based on the case of a string passed to the sub as the first parameter. So, if my string is in uppercase, the subroutine should return '\U', it should return '\L' otherwise. For example,
my $esc_char = get_escape_case("S");
would return '\U' escape character. I may then use it (or so I hope to) to format any other string (either uppercase or lowercase it) by simply prepending the escape character in an expression like this:
my $case_formatted_string = $esc_char ."FoobAr";
In this example (where $esc_char is '\U') $case_formatted_string should become 'FOOBAR' (since "S" is in uppercase).

The only problem that I'm facing now is how do I actually apply this escape character to a string? I've tried one obvious way in a sample code below but it didn't work:
use strict; # determine case of a character # and return appropriate 'control' code. sub get_escape_case { my ($char) = @_; if ($char eq "\U$char") { return '\U'; } else { return '\L'; } } # this wouldn't work... print get_escape_case("S")."stuff\n"; # while this works.. print "\Ustuff\n";
I guess I might have to use a special 'code' for the escape character? Could anyone lead me in the right path? Thank you. ;-)

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