In unix, this is already done by the shell

$ perl -le'print for @ARGV' a.xml
a.xml

$ perl -le'print for @ARGV' *.xml
a.xml
b.xml

$ perl -le'print for @ARGV' foo/*.xml
foo/x.xml
foo/y.xml
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To handle Windows too, you just need to add the following code to your script:

BEGIN {
    if ($^O =~ /MSWin32/) {
        require File::Glob;
        @ARGV = map File::Glob::bsd_glob($_), @ARGV;
    }
}
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