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uc EXPR
uc

Returns an uppercased version of EXPR. If EXPR is omitted, uses $_.

my $str = uc("Perl is GREAT"); # "PERL IS GREAT"

This function behaves the same way under various pragmas, such as in a locale, as lc does.

If you want titlecase mapping on initial letters see ucfirst instead.

Note: This is the internal function implementing the \U escape in double-quoted strings.

my $str = "Perl is \Ugreat\E"; # "Perl is GREAT"