I think you'd want something like this to create your catFiles.pl script:

#!perl

# called as catFiles.pl input1 input2 > output

exec( qw(perl -MExtUtils::Command -e cat), @ARGV );
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Or if you want a different way of executing the command:

#!perl -w

# called as catFiles.pl output input1 input2

use strict;

my ($output, @inputs) = @ARGV;
exec("perl -MExtUtils::Command -e cat @inputs > $output");
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