As long as the options are all being stored in one hash anyhow, I think the reference-to-options-hash usage of Getopts::Long is easier to read:

[snip]

# Process and validate the command line options in @ARGV.
my %options;
GetOptions (
    \%options,
    qw{
        infile=s
        outfile=s
        help
    }
) or help();

[snip]
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